Here we go again
- Thread starter Thigh19
- Start date
I think that is a little small depending on what you are going to do. If
all you do is run a few lights it may be enough but if you are going to do
the work why not make it meaningful? I thin you should consider a 390 to
400 watt rigid panel as the lid for a cargo pod. If you do not aim the
panel you would get much less than rated nameplate output.
On Fri, Nov 1, 2019 at 12:14 PM Thom High via Gmclist <
> I know this subject has probably been beaten to death, but I'm
> contemplating s9lar. Is 100 watt panel enough? Flexible or rigid panel?
> Don't want to
> do a lot of off grid, but want to keep my 2 6volt golf cart batteries
> charged. Have a 1973 Sequoia
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
*John Phillips*
all you do is run a few lights it may be enough but if you are going to do
the work why not make it meaningful? I thin you should consider a 390 to
400 watt rigid panel as the lid for a cargo pod. If you do not aim the
panel you would get much less than rated nameplate output.
On Fri, Nov 1, 2019 at 12:14 PM Thom High via Gmclist <
> I know this subject has probably been beaten to death, but I'm
> contemplating s9lar. Is 100 watt panel enough? Flexible or rigid panel?
> Don't want to
> do a lot of off grid, but want to keep my 2 6volt golf cart batteries
> charged. Have a 1973 Sequoia
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
*John Phillips*
I got by with a single 140 watt panel for a few years, but have since added a 55 watt panel to help out. It works well for what we do and how we
manage our electricity use:
http://www.gmcmhphotos.com/photos/g6227-solar-battery-charging.html
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging. GMCSJ and GMCMI member
manage our electricity use:
http://www.gmcmhphotos.com/photos/g6227-solar-battery-charging.html
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging. GMCSJ and GMCMI member
If its just to keep the batteries topped off 100 watts will be enough. More importantly I think you should consider getting a good solar controller
that monitors your usage over time. With this data it will be obvious whether or not you need more solar.
I went with 200 watts of flexible panels tapped on to the roof using eternabond. The hard part was running the wires but now that they are set if I
need to it will be easy to upgrade to a larger panel.
--
Angel Rodriguez
San Jose, CA
1978 23' Birchhaven
that monitors your usage over time. With this data it will be obvious whether or not you need more solar.
I went with 200 watts of flexible panels tapped on to the roof using eternabond. The hard part was running the wires but now that they are set if I
need to it will be easy to upgrade to a larger panel.
--
Angel Rodriguez
San Jose, CA
1978 23' Birchhaven
> I know this subject has probably been beaten to death, but I'm contemplating s9lar. Is 100 watt panel enough? Flexible or rigid panel? Don't want
> to do a lot of off grid, but want to keep my 2 6volt golf cart batteries charged. Have a 1973 Sequoia
First Questions.......
What are you planning to power?
- If you only plan to keep the battery alive while the coach is parked, a 50 watt panel will take care of that.
- If you plan to use the solar for power, we have MORE questions.
- Are you supplying only 12v dc power appliances? This should be easier for you. To get the Amp rating of a panel, you divide the panel (100 watt)
by the voltage (12v dc) which would be 8 AMPs.
Most 12v appliances are low amp ratings, or low watt ratings.
More Understanding ---- Your best solar charge is at Sun hours. This generally is related to static homes, and can vary from 3 to 5 hours per day.
A 100 watt solar panel in a 4 sun hour day will charge up to 400 watts, or 32 amps.
Another thought, If you have a 100AH battery, that 100 watt solar panel will take over 3 days to restore a battery that has been discharged.
If you are planning on using an inverter, prepare to be shocked.
In order for a inverter to create 5 amps of 120v ac power, your battery needs to supply 50 amps of 12v dc power.
A fast rough idea of time.... a 12v dc 100 AH lead acid battery will supply 5 amps for 20 hours. The above example would not last long.
Another fast thought......... Batteries, either Lead Acid or Lithium, do not like to supply high amps for extended periods. If you can keep the draw
down around 5 amps, occasional spikes to 10 amps is ok, the battery will have a longer life.
So if you planned to run 15 amps often from your batteries, You may want to supply two batteries. 15 AMPs would be supplied by two 100 AH batteries
at 7.5 amp per battery. Checking the rough guide above, you'd have about 15 hours.
Panel depend on how you will be supplying power.
FIRST ----- Flexible are not highly recommended. The flexible panels tend to fail in 4 years. No matter how you care for them, the inner circuitry
seems to break down. The flexible panels have no good cooling method and heat is detrimental to flex panels.
In the case where you have a space problem and the flex panels seem to be the only choice, look for a TOP BRAND panel with a warrentee, but be warned,
the flex panels tend to go away as fast as they show up. most are made in China and no matter how long your warrantee is, they most likely will not
exist by the time yours fails.
In framed panels there are two types, Poly and mono. One is suppose to be better than the other but according to tests, they both perform pretty much
the same in sun/shade. Do some research on this if you want to be picky about which you go after but the test results concluded that there are not
large differences.
The space you have on your RV will most likely be the determining factor of how many panels you can have.
300 watts is a good number but again, what are you going to use it for.
If you want to run TV lights and computer at night, you have to figure your loads, play with the battery numbers, figure sun hours (yes it is
important even in an RV) and then go with it.
Here is a quick list
Coffee makr 950 watts
Toaster oven 1200 watts
MicrWave 750 watts
Sm Floor htr 750 watts
Lg floor htr 1500 watts
Sm Tv 90 watts
DVD player 60 watts
16 cu ft frost free frig 725 watts
Xbox 360 106 watts
rv frig 343 watts
Stereo Recvr 75 watts
Computer 120 watts
Telephone 100 watts
Florescent lamp 20 watts
fan 100 watts
Figure these figures as ONE HOUR USE. If using the tv for 3 hours, multiply the 90 watts by 3 for one days use.
So if you are using the tv for 3 hours at 90 watts total is 270 watts
in a 4 hour sun day area, a 300 watt set of panels can produce 1200 watts, that is enough to cover the 270 watts for the
tv and to charge the batteries.
Play with the numbers and see where you might end up.
Also look in to the mppt controllers. They are supposed to charged even when not in direct sunlight.
[ PANEL ] = [ roof fuse ] = [ Regulator ] = [ ckt breaker ] = [BATTERY]
I mention the roof fuse because recently the rv community has had a bad installer install solar to unsuspecting users. He
made the hole through the roof too small and scraped the insulation from the power wires. Several Rvs have burnt down
recently because of this installer.
Besides, you need to protect your sources both from the panel and from the battery.
good luck.
--
GatsbysCruise. \
74GMC260 Former Glacier Model style. \
Waukegan, Illinois \ Keep those MiniDiscs Spinning \ MY GREYHOUND IS FASTER THAN YOUR HONOR ROLL STUDENT \ WindowsXP-Win7-Win8.1-UBUNTU STUDIO -
UBUNTU VOYAGER - Berzin Auto Center
> to do a lot of off grid, but want to keep my 2 6volt golf cart batteries charged. Have a 1973 Sequoia
First Questions.......
What are you planning to power?
- If you only plan to keep the battery alive while the coach is parked, a 50 watt panel will take care of that.
- If you plan to use the solar for power, we have MORE questions.
- Are you supplying only 12v dc power appliances? This should be easier for you. To get the Amp rating of a panel, you divide the panel (100 watt)
by the voltage (12v dc) which would be 8 AMPs.
Most 12v appliances are low amp ratings, or low watt ratings.
More Understanding ---- Your best solar charge is at Sun hours. This generally is related to static homes, and can vary from 3 to 5 hours per day.
A 100 watt solar panel in a 4 sun hour day will charge up to 400 watts, or 32 amps.
Another thought, If you have a 100AH battery, that 100 watt solar panel will take over 3 days to restore a battery that has been discharged.
If you are planning on using an inverter, prepare to be shocked.
In order for a inverter to create 5 amps of 120v ac power, your battery needs to supply 50 amps of 12v dc power.
A fast rough idea of time.... a 12v dc 100 AH lead acid battery will supply 5 amps for 20 hours. The above example would not last long.
Another fast thought......... Batteries, either Lead Acid or Lithium, do not like to supply high amps for extended periods. If you can keep the draw
down around 5 amps, occasional spikes to 10 amps is ok, the battery will have a longer life.
So if you planned to run 15 amps often from your batteries, You may want to supply two batteries. 15 AMPs would be supplied by two 100 AH batteries
at 7.5 amp per battery. Checking the rough guide above, you'd have about 15 hours.
Panel depend on how you will be supplying power.
FIRST ----- Flexible are not highly recommended. The flexible panels tend to fail in 4 years. No matter how you care for them, the inner circuitry
seems to break down. The flexible panels have no good cooling method and heat is detrimental to flex panels.
In the case where you have a space problem and the flex panels seem to be the only choice, look for a TOP BRAND panel with a warrentee, but be warned,
the flex panels tend to go away as fast as they show up. most are made in China and no matter how long your warrantee is, they most likely will not
exist by the time yours fails.
In framed panels there are two types, Poly and mono. One is suppose to be better than the other but according to tests, they both perform pretty much
the same in sun/shade. Do some research on this if you want to be picky about which you go after but the test results concluded that there are not
large differences.
The space you have on your RV will most likely be the determining factor of how many panels you can have.
300 watts is a good number but again, what are you going to use it for.
If you want to run TV lights and computer at night, you have to figure your loads, play with the battery numbers, figure sun hours (yes it is
important even in an RV) and then go with it.
Here is a quick list
Coffee makr 950 watts
Toaster oven 1200 watts
MicrWave 750 watts
Sm Floor htr 750 watts
Lg floor htr 1500 watts
Sm Tv 90 watts
DVD player 60 watts
16 cu ft frost free frig 725 watts
Xbox 360 106 watts
rv frig 343 watts
Stereo Recvr 75 watts
Computer 120 watts
Telephone 100 watts
Florescent lamp 20 watts
fan 100 watts
Figure these figures as ONE HOUR USE. If using the tv for 3 hours, multiply the 90 watts by 3 for one days use.
So if you are using the tv for 3 hours at 90 watts total is 270 watts
in a 4 hour sun day area, a 300 watt set of panels can produce 1200 watts, that is enough to cover the 270 watts for the
tv and to charge the batteries.
Play with the numbers and see where you might end up.
Also look in to the mppt controllers. They are supposed to charged even when not in direct sunlight.
[ PANEL ] = [ roof fuse ] = [ Regulator ] = [ ckt breaker ] = [BATTERY]
I mention the roof fuse because recently the rv community has had a bad installer install solar to unsuspecting users. He
made the hole through the roof too small and scraped the insulation from the power wires. Several Rvs have burnt down
recently because of this installer.
Besides, you need to protect your sources both from the panel and from the battery.
good luck.
--
GatsbysCruise. \
74GMC260 Former Glacier Model style. \
Waukegan, Illinois \ Keep those MiniDiscs Spinning \ MY GREYHOUND IS FASTER THAN YOUR HONOR ROLL STUDENT \ WindowsXP-Win7-Win8.1-UBUNTU STUDIO -
UBUNTU VOYAGER - Berzin Auto Center
Gatsby you're muddling up your units. Watts are a rate of use, you need the duration in order to size the battery and panels.
For instance, a coffee maker at 950W running for an hour doesn't consume 950W from a system. It would have consumed 950 Watt-hr. Or 0.950 kW-hr to
put it in units familiar on an electric bill.
The 90 Watt tv running for 3 hours doesn't consume 270 Watts, it consumes 270 Watt-hours.
That's why the battery capacity is expressed in Amp-hours. It's not the rate, it's the rate multiplied by the time. A 100 Amp-hr battery capacity at
12V can also be expressed as 1200 Watt-hour since DC watts = Volts * Amps
If everything is expressed in the same units it easier to work out a budget and size the panels and battery.
Also critical is the efficiency of each step of the process. B/c that 90 Amp TV running on a battery through an invertor isn't pulling 90A from the
battery, it's pulling 90A / efficiency. There's also an efficiency of charging the battery from the panels, that's not 100% either. It's better to
assume a low efficiency and size your system conservatively up front than to asssume optimistic values and run out of power later on.
> > I know this subject has probably been beaten to death, but I'm contemplating s9lar. Is 100 watt panel enough? Flexible or rigid panel? Don't
> > want to do a lot of off grid, but want to keep my 2 6volt golf cart batteries charged. Have a 1973 Sequoia
>
> First Questions.......
> What are you planning to power?
> - If you only plan to keep the battery alive while the coach is parked, a 50 watt panel will take care of that.
> - If you plan to use the solar for power, we have MORE questions.
> - Are you supplying only 12v dc power appliances? This should be easier for you. To get the Amp rating of a panel, you divide the panel (100
> watt) by the voltage (12v dc) which would be 8 AMPs.
> Most 12v appliances are low amp ratings, or low watt ratings.
> More Understanding ---- Your best solar charge is at Sun hours. This generally is related to static homes, and can vary from 3 to 5 hours per
> day.
> A 100 watt solar panel in a 4 sun hour day will charge up to 400 watts, or 32 amps.
> Another thought, If you have a 100AH battery, that 100 watt solar panel will take over 3 days to restore a battery that has been discharged.
>
> If you are planning on using an inverter, prepare to be shocked.
> In order for a inverter to create 5 amps of 120v ac power, your battery needs to supply 50 amps of 12v dc power.
>
> A fast rough idea of time.... a 12v dc 100 AH lead acid battery will supply 5 amps for 20 hours. The above example would not last long.
>
> Another fast thought......... Batteries, either Lead Acid or Lithium, do not like to supply high amps for extended periods. If you can keep the
> draw down around 5 amps, occasional spikes to 10 amps is ok, the battery will have a longer life.
> So if you planned to run 15 amps often from your batteries, You may want to supply two batteries. 15 AMPs would be supplied by two 100 AH
> batteries at 7.5 amp per battery. Checking the rough guide above, you'd have about 15 hours.
>
> Panel depend on how you will be supplying power.
> FIRST ----- Flexible are not highly recommended. The flexible panels tend to fail in 4 years. No matter how you care for them, the inner
> circuitry seems to break down. The flexible panels have no good cooling method and heat is detrimental to flex panels.
> In the case where you have a space problem and the flex panels seem to be the only choice, look for a TOP BRAND panel with a warrentee, but be
> warned, the flex panels tend to go away as fast as they show up. most are made in China and no matter how long your warrantee is, they most likely
> will not exist by the time yours fails.
>
> In framed panels there are two types, Poly and mono. One is suppose to be better than the other but according to tests, they both perform pretty
> much the same in sun/shade. Do some research on this if you want to be picky about which you go after but the test results concluded that there are
> not large differences.
>
> The space you have on your RV will most likely be the determining factor of how many panels you can have.
> 300 watts is a good number but again, what are you going to use it for.
> If you want to run TV lights and computer at night, you have to figure your loads, play with the battery numbers, figure sun hours (yes it is
> important even in an RV) and then go with it.
>
> Here is a quick list
>
> Coffee makr 950 watts
> Toaster oven 1200 watts
> MicrWave 750 watts
> Sm Floor htr 750 watts
> Lg floor htr 1500 watts
> Sm Tv 90 watts
> DVD player 60 watts
> 16 cu ft frost free frig 725 watts
> Xbox 360 106 watts
> rv frig 343 watts
> Stereo Recvr 75 watts
> Computer 120 watts
> Telephone 100 watts
> Florescent lamp 20 watts
> fan 100 watts
>
> Figure these figures as ONE HOUR USE. If using the tv for 3 hours, multiply the 90 watts by 3 for one days use.
>
> So if you are using the tv for 3 hours at 90 watts total is 270 watts
>
> in a 4 hour sun day area, a 300 watt set of panels can produce 1200 watts, that is enough to cover the 270 watts for the
> tv and to charge the batteries.
>
> Play with the numbers and see where you might end up.
> Also look in to the mppt controllers. They are supposed to charged even when not in direct sunlight.
>
> [ PANEL ] = [ roof fuse ] = [ Regulator ] = [ ckt breaker ] = [BATTERY]
>
> I mention the roof fuse because recently the rv community has had a bad installer install solar to unsuspecting users. He
> made the hole through the roof too small and scraped the insulation from the power wires. Several Rvs have burnt down
> recently because of this installer.
> Besides, you need to protect your sources both from the panel and from the battery.
>
> good luck.
--
Todd Snyder, Buffalo NY
1976 Eleganza II
For instance, a coffee maker at 950W running for an hour doesn't consume 950W from a system. It would have consumed 950 Watt-hr. Or 0.950 kW-hr to
put it in units familiar on an electric bill.
The 90 Watt tv running for 3 hours doesn't consume 270 Watts, it consumes 270 Watt-hours.
That's why the battery capacity is expressed in Amp-hours. It's not the rate, it's the rate multiplied by the time. A 100 Amp-hr battery capacity at
12V can also be expressed as 1200 Watt-hour since DC watts = Volts * Amps
If everything is expressed in the same units it easier to work out a budget and size the panels and battery.
Also critical is the efficiency of each step of the process. B/c that 90 Amp TV running on a battery through an invertor isn't pulling 90A from the
battery, it's pulling 90A / efficiency. There's also an efficiency of charging the battery from the panels, that's not 100% either. It's better to
assume a low efficiency and size your system conservatively up front than to asssume optimistic values and run out of power later on.
> > I know this subject has probably been beaten to death, but I'm contemplating s9lar. Is 100 watt panel enough? Flexible or rigid panel? Don't
> > want to do a lot of off grid, but want to keep my 2 6volt golf cart batteries charged. Have a 1973 Sequoia
>
> First Questions.......
> What are you planning to power?
> - If you only plan to keep the battery alive while the coach is parked, a 50 watt panel will take care of that.
> - If you plan to use the solar for power, we have MORE questions.
> - Are you supplying only 12v dc power appliances? This should be easier for you. To get the Amp rating of a panel, you divide the panel (100
> watt) by the voltage (12v dc) which would be 8 AMPs.
> Most 12v appliances are low amp ratings, or low watt ratings.
> More Understanding ---- Your best solar charge is at Sun hours. This generally is related to static homes, and can vary from 3 to 5 hours per
> day.
> A 100 watt solar panel in a 4 sun hour day will charge up to 400 watts, or 32 amps.
> Another thought, If you have a 100AH battery, that 100 watt solar panel will take over 3 days to restore a battery that has been discharged.
>
> If you are planning on using an inverter, prepare to be shocked.
> In order for a inverter to create 5 amps of 120v ac power, your battery needs to supply 50 amps of 12v dc power.
>
> A fast rough idea of time.... a 12v dc 100 AH lead acid battery will supply 5 amps for 20 hours. The above example would not last long.
>
> Another fast thought......... Batteries, either Lead Acid or Lithium, do not like to supply high amps for extended periods. If you can keep the
> draw down around 5 amps, occasional spikes to 10 amps is ok, the battery will have a longer life.
> So if you planned to run 15 amps often from your batteries, You may want to supply two batteries. 15 AMPs would be supplied by two 100 AH
> batteries at 7.5 amp per battery. Checking the rough guide above, you'd have about 15 hours.
>
> Panel depend on how you will be supplying power.
> FIRST ----- Flexible are not highly recommended. The flexible panels tend to fail in 4 years. No matter how you care for them, the inner
> circuitry seems to break down. The flexible panels have no good cooling method and heat is detrimental to flex panels.
> In the case where you have a space problem and the flex panels seem to be the only choice, look for a TOP BRAND panel with a warrentee, but be
> warned, the flex panels tend to go away as fast as they show up. most are made in China and no matter how long your warrantee is, they most likely
> will not exist by the time yours fails.
>
> In framed panels there are two types, Poly and mono. One is suppose to be better than the other but according to tests, they both perform pretty
> much the same in sun/shade. Do some research on this if you want to be picky about which you go after but the test results concluded that there are
> not large differences.
>
> The space you have on your RV will most likely be the determining factor of how many panels you can have.
> 300 watts is a good number but again, what are you going to use it for.
> If you want to run TV lights and computer at night, you have to figure your loads, play with the battery numbers, figure sun hours (yes it is
> important even in an RV) and then go with it.
>
> Here is a quick list
>
> Coffee makr 950 watts
> Toaster oven 1200 watts
> MicrWave 750 watts
> Sm Floor htr 750 watts
> Lg floor htr 1500 watts
> Sm Tv 90 watts
> DVD player 60 watts
> 16 cu ft frost free frig 725 watts
> Xbox 360 106 watts
> rv frig 343 watts
> Stereo Recvr 75 watts
> Computer 120 watts
> Telephone 100 watts
> Florescent lamp 20 watts
> fan 100 watts
>
> Figure these figures as ONE HOUR USE. If using the tv for 3 hours, multiply the 90 watts by 3 for one days use.
>
> So if you are using the tv for 3 hours at 90 watts total is 270 watts
>
> in a 4 hour sun day area, a 300 watt set of panels can produce 1200 watts, that is enough to cover the 270 watts for the
> tv and to charge the batteries.
>
> Play with the numbers and see where you might end up.
> Also look in to the mppt controllers. They are supposed to charged even when not in direct sunlight.
>
> [ PANEL ] = [ roof fuse ] = [ Regulator ] = [ ckt breaker ] = [BATTERY]
>
> I mention the roof fuse because recently the rv community has had a bad installer install solar to unsuspecting users. He
> made the hole through the roof too small and scraped the insulation from the power wires. Several Rvs have burnt down
> recently because of this installer.
> Besides, you need to protect your sources both from the panel and from the battery.
>
> good luck.
--
Todd Snyder, Buffalo NY
1976 Eleganza II
Also a 100W solar panel will almost never give you 100W. 50-60W might be more realistic unless you can track the sun, eliminate all trees etc. There
is also slight drop over time.
--
John Lebetski
Woodstock, IL
77 Eleganza II
is also slight drop over time.
--
John Lebetski
Woodstock, IL
77 Eleganza II
I’m putting a 325 watt panel on eldest daughters horse trailer.
It’s function is to run ONE fantastic fan, charge cellphones, and a light.
Oh, and a couple of golf car batteries (and a controller). No shore power charger.
I expect to see maybe 165 watts from it. When the sun is shining.
Dolph
DE AD0LF
Wheeling, West Virginia
1977 26’ ex-PalmBeach
Howell EFI & EBL, Reaction Arms, Manny Transmission
“The Aluminum and Fiberglass Mistress"
>
> Also a 100W solar panel will almost never give you 100W. 50-60W might be more realistic unless you can track the sun, eliminate all trees etc. There
> is also slight drop over time.
> --
> John Lebetski
> Woodstock, IL
> 77 Eleganza II
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
It’s function is to run ONE fantastic fan, charge cellphones, and a light.
Oh, and a couple of golf car batteries (and a controller). No shore power charger.
I expect to see maybe 165 watts from it. When the sun is shining.
Dolph
DE AD0LF
Wheeling, West Virginia
1977 26’ ex-PalmBeach
Howell EFI & EBL, Reaction Arms, Manny Transmission
“The Aluminum and Fiberglass Mistress"
>
> Also a 100W solar panel will almost never give you 100W. 50-60W might be more realistic unless you can track the sun, eliminate all trees etc. There
> is also slight drop over time.
> --
> John Lebetski
> Woodstock, IL
> 77 Eleganza II
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Just to clarify, in his last paragraph where Todd referred to the 90 Amp TV, he meant 90 Watts. So a TV consuming 90 Watts through an Inverter with
an efficiency of 80% would consume approximately 112 watts (90/0.8) from the battery. In round figures, that's about 10Amps at 12V Over 3 hours that
would be 336 watt-hrs or about 1/3 of the 100 Amp/hr battery's capacity.
But don't forget you shouldn't discharge a lead-acid battery beyond 50% or its cycle life will drop drastically. So in real terms that's about all you
could discharge from a lead-acid battery considering you likely also had an LED light on, used the water pump a few times and even a roof fan going.
Actually if you had watched TV and had the roof fan going all night you would likely have deep discharged the 100 Amp-hr battery by morning.
My 150W panel flat on top of my storage pod through a PWM controller will give me about 6.5 amps @ 13.8V = 90 watts in bright sunshine. My panel is
rated at 8.3 Amps @ 18V, so with a MPPT controller I might be able to get 8.3A x 13.8V = 115W. I would need to track the sun to get close to the rated
150 watts from the panel.
Unless you have lots of solar panel power and lots of battery capacity (LiFePO4 batteries... Read $$$), you are better to start the generator to run
high current appliances like coffee makers, microwaves and toasters.
Just my 2 cents.
--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
an efficiency of 80% would consume approximately 112 watts (90/0.8) from the battery. In round figures, that's about 10Amps at 12V Over 3 hours that
would be 336 watt-hrs or about 1/3 of the 100 Amp/hr battery's capacity.
But don't forget you shouldn't discharge a lead-acid battery beyond 50% or its cycle life will drop drastically. So in real terms that's about all you
could discharge from a lead-acid battery considering you likely also had an LED light on, used the water pump a few times and even a roof fan going.
Actually if you had watched TV and had the roof fan going all night you would likely have deep discharged the 100 Amp-hr battery by morning.
My 150W panel flat on top of my storage pod through a PWM controller will give me about 6.5 amps @ 13.8V = 90 watts in bright sunshine. My panel is
rated at 8.3 Amps @ 18V, so with a MPPT controller I might be able to get 8.3A x 13.8V = 115W. I would need to track the sun to get close to the rated
150 watts from the panel.
Unless you have lots of solar panel power and lots of battery capacity (LiFePO4 batteries... Read $$$), you are better to start the generator to run
high current appliances like coffee makers, microwaves and toasters.
Just my 2 cents.
--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
I read Jerry Work's presentation about lithium batteries and all that goes with them with great interest. I'd like solar to keep the batteries
healthy while parked, but really the utility of solar panels for me is limited. The batteries will almost always be fully charged by the alternator
when I reach a campsite. Our usage isn't great and we rarely stay in one place very long. Along with the fact that we don't have a towd, we drive
the coach into town - if that's what we want to do.
Lithium would allow us to be off-grid longer than we ever have been. It's tough to make the jump when Costco has the 6v deep cycle batteries for
$100. Solar would allow me to use the Onan less, I suppose, but it's working well (and paid for). I want lithium batteries and solar panels, but our
usage doesn't justify the expense.
Proofreading this made me chuckle - justify the expense of our motorhome - HA!!
--
Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
healthy while parked, but really the utility of solar panels for me is limited. The batteries will almost always be fully charged by the alternator
when I reach a campsite. Our usage isn't great and we rarely stay in one place very long. Along with the fact that we don't have a towd, we drive
the coach into town - if that's what we want to do.
Lithium would allow us to be off-grid longer than we ever have been. It's tough to make the jump when Costco has the 6v deep cycle batteries for
$100. Solar would allow me to use the Onan less, I suppose, but it's working well (and paid for). I want lithium batteries and solar panels, but our
usage doesn't justify the expense.
Proofreading this made me chuckle - justify the expense of our motorhome - HA!!
--
Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
As I am fully in play mode with solar now, ALL my figures are created in hourly segments unless otherwise stated.
I created many Exile worksheets to play with the numbers, and I will admit I am not perfect but I am getting some
pretty good numbers that compare to working systems.
My original comment was an attempt to help the user understand that SOLAR is a balancing act between the panels, batteries and the load.
One scenario is where you may have a high count of solar watts which allows you to run some appliances during the sun hours
while the batteries maintain charge.
Another scenario is where you charge the batteries during the day and use the battery storage in the evening, requiring more batteries.
The scenarios go on and on, it is all a customizing game to the use you have for the system.
No one system is the same.
My only comments on the batteries is they need something charging them, solar, vehicle alternator, generator or all of the above.
Recent reads have come up with information that says that even though you CAN use the power in a battery and run its level down, IDEALLY, you want
your battery levels high, near full.
We had lead acid batteries in battery banks that would last 25 years.
the Lithiums, and i am not going to get into an argument over these new batteries, but they have concerns that no one seems to
consider. All that is heard is they can last longer and discharge further. I will say that is true, but, they don't like
that deep of a discharge and every deep discharge is taking some life away from the battery.
Also, NO BATTERY likes High loads for extended periods. Besides shortening the life of the battery, extreme high loads will find your
system weak spots, usually connections, and they will get hot or burn. That is why I mentioned that time measure formula some kind
person offered here at GMC net at one time, it is a loose figure to work with,
but it is close enough to get an idea of what you are working with.
IDEALLY, the batteries like low loads of 5 to 10 amps. You start to get high loads from the batteries, you need more batteries
to share the load.
Running the inverter is expensive on your battery power. at 12v dc, its a factor of 10. 20 amps of 12v dc into the inverter
will supply 2 amps of 120v AC. The normal roof top AC is plus or minus about 9 amps, which would be 90 amps from the battery/hr.
So that is not likely to happen as physically, the GMC does not have enough roof for panels or space for batteries to support that.
The RV Nomads have taken to home windows units which run at about 3-4 amps/hr to run. This translates to 30 to 40 amps of 12v dc into
the inverter, still requires an extra panel or two and one or two more batteries, but it can be done.
One important thing to keep in mind is if you draw high amps from the Lithium batteries, they start to get hot. That should be a warning
but most just ignore it. The article I read said that if those components, and that chemical mix begins to ignite, that battery
fire is very difficult to put out, and you cannot use water on a lithium battery fire. If the fire department finds out there are
lithium batteries involved in a fire, they become much more cautious about attacking that fire. So much so you may lose your rig.
This is the main reason that batteries, including Lithium batteries, should be planned to supply low current loads, within reason, to the system
including the inverter.
Keeping the current loads down extends the battery life and runs at a much safer operating margin.
For myself, my rig sits over winter so Lithiums do not fit the plan for solar storage because of temperature..
My batteries are and will be some form of lead acid, probably gel because lead acid can handle much more abuse over the lithiums.
Talking about batteries these days, especially with the lithiums out there is dangerous because people form their opinions and once they set their
minds, there is no changing them. Lithium batteries have more or less morphed 2twice that I know of now and the rules have changed. They are not the
magic cells that people talk about and require very similar care and use that the Lead acid cells do.
The Lithium cells are one area that I have kept an eye on and read the articles so there is a lot to learn about them. In some ways they can
be more dangerous than using Lead Acid, but most won't understand this until something bad happens. and we move forward.
--
GatsbysCruise. \
74GMC260 Former Glacier Model style. \
Waukegan, Illinois \ Keep those MiniDiscs Spinning \ MY GREYHOUND IS FASTER THAN YOUR HONOR ROLL STUDENT \ WindowsXP-Win7-Win8.1-UBUNTU STUDIO -
UBUNTU VOYAGER - Berzin Auto Center
I created many Exile worksheets to play with the numbers, and I will admit I am not perfect but I am getting some
pretty good numbers that compare to working systems.
My original comment was an attempt to help the user understand that SOLAR is a balancing act between the panels, batteries and the load.
One scenario is where you may have a high count of solar watts which allows you to run some appliances during the sun hours
while the batteries maintain charge.
Another scenario is where you charge the batteries during the day and use the battery storage in the evening, requiring more batteries.
The scenarios go on and on, it is all a customizing game to the use you have for the system.
No one system is the same.
My only comments on the batteries is they need something charging them, solar, vehicle alternator, generator or all of the above.
Recent reads have come up with information that says that even though you CAN use the power in a battery and run its level down, IDEALLY, you want
your battery levels high, near full.
We had lead acid batteries in battery banks that would last 25 years.
the Lithiums, and i am not going to get into an argument over these new batteries, but they have concerns that no one seems to
consider. All that is heard is they can last longer and discharge further. I will say that is true, but, they don't like
that deep of a discharge and every deep discharge is taking some life away from the battery.
Also, NO BATTERY likes High loads for extended periods. Besides shortening the life of the battery, extreme high loads will find your
system weak spots, usually connections, and they will get hot or burn. That is why I mentioned that time measure formula some kind
person offered here at GMC net at one time, it is a loose figure to work with,
but it is close enough to get an idea of what you are working with.
IDEALLY, the batteries like low loads of 5 to 10 amps. You start to get high loads from the batteries, you need more batteries
to share the load.
Running the inverter is expensive on your battery power. at 12v dc, its a factor of 10. 20 amps of 12v dc into the inverter
will supply 2 amps of 120v AC. The normal roof top AC is plus or minus about 9 amps, which would be 90 amps from the battery/hr.
So that is not likely to happen as physically, the GMC does not have enough roof for panels or space for batteries to support that.
The RV Nomads have taken to home windows units which run at about 3-4 amps/hr to run. This translates to 30 to 40 amps of 12v dc into
the inverter, still requires an extra panel or two and one or two more batteries, but it can be done.
One important thing to keep in mind is if you draw high amps from the Lithium batteries, they start to get hot. That should be a warning
but most just ignore it. The article I read said that if those components, and that chemical mix begins to ignite, that battery
fire is very difficult to put out, and you cannot use water on a lithium battery fire. If the fire department finds out there are
lithium batteries involved in a fire, they become much more cautious about attacking that fire. So much so you may lose your rig.
This is the main reason that batteries, including Lithium batteries, should be planned to supply low current loads, within reason, to the system
including the inverter.
Keeping the current loads down extends the battery life and runs at a much safer operating margin.
For myself, my rig sits over winter so Lithiums do not fit the plan for solar storage because of temperature..
My batteries are and will be some form of lead acid, probably gel because lead acid can handle much more abuse over the lithiums.
Talking about batteries these days, especially with the lithiums out there is dangerous because people form their opinions and once they set their
minds, there is no changing them. Lithium batteries have more or less morphed 2twice that I know of now and the rules have changed. They are not the
magic cells that people talk about and require very similar care and use that the Lead acid cells do.
The Lithium cells are one area that I have kept an eye on and read the articles so there is a lot to learn about them. In some ways they can
be more dangerous than using Lead Acid, but most won't understand this until something bad happens. and we move forward.
--
GatsbysCruise. \
74GMC260 Former Glacier Model style. \
Waukegan, Illinois \ Keep those MiniDiscs Spinning \ MY GREYHOUND IS FASTER THAN YOUR HONOR ROLL STUDENT \ WindowsXP-Win7-Win8.1-UBUNTU STUDIO -
UBUNTU VOYAGER - Berzin Auto Center
> As I am fully in play mode with solar now, ALL my figures are created in hourly segments unless otherwise stated.
> I created many Ecell worksheets to play with the numbers, and I will admit I am not perfect but I am getting some
> pretty good numbers that compare to working systems.
>
> My original comment was an attempt to help the user understand that SOLAR is a balancing act between the panels, batteries and the load.
> One scenario is where you may have a high count of solar watts which allows you to run some appliances during the sun hours
> while the batteries maintain charge.
> Another scenario is where you charge the batteries during the day and use the battery storage in the evening, requiring more batteries.
> The scenarios go on and on, it is all a customizing game to the use you have for the system.
> No one system is the same.
>
> My only comments on the batteries is they need something charging them, solar, vehicle alternator, generator or all of the above.
> Recent reads have come up with information that says that even though you CAN use the power in a battery and run its level down, IDEALLY, you want
>
> your battery levels high, near full.
> We had lead acid batteries in battery banks that would last 25 years.
> the Lithiums, and i am not going to get into an argument over these new batteries, but they have concerns that no one seems to
> consider. All that is heard is they can last longer and discharge further. I will say that is true, but, they don't like
> that deep of a discharge and every deep discharge is taking some life away from the battery.
> Also, NO BATTERY likes High loads for extended periods. Besides shortening the life of the battery, extreme high loads will find your
> system weak spots, usually connections, and they will get hot or burn. That is why I mentioned that time measure formula some kind
> person offered here at GMC net at one time, it is a loose figure to work with,
> but it is close enough to get an idea of what you are working with.
>
> IDEALLY, the batteries like low loads of 5 to 10 amps. You start to get high loads from the batteries, you need more batteries
> to share the load.
>
> Running the inverter is expensive on your battery power. at 12v dc, its a factor of 10. 20 amps of 12v dc into the inverter
> will supply 2 amps of 120v AC. The normal roof top AC is plus or minus about 9 amps, which would be 90 amps from the battery/hr.
> So that is not likely to happen as physically, the GMC does not have enough roof for panels or space for batteries to support that.
>
> The RV Nomads have taken to home windows units which run at about 3-4 amps/hr to run. This translates to 30 to 40 amps/hr of 12v dc into
> the inverter, still requires an extra panel or two and one or two more batteries, but it can be done.
>
> One important thing to keep in mind is if you draw high amps from the Lithium batteries, they start to get hot. That should be a warning
> but most don't understand. The article I read said that if those components, and that chemical mix begins to ignite, that battery
> fire is very difficult to put out, and you cannot use water on a lithium battery fire. If the fire department finds out there are
> lithium batteries involved in a fire, they become much more cautious about attacking that fire. So much so you may lose your rig.
>
> This is the main reason that batteries, including Lithium batteries, should be planned to supply low current loads, within reason, to the system
> including the inverter.
> Keeping the current loads down extends the battery life and runs at a much safer operating margin.
To be honest with you it depends on the chemistry of the lithium battery....most of them on the public market are of the safer variety and are quite
safe if not over exerted. The problem is people dont understand that not only high discharge rates affect lithium ion batteries also high charge
rates.....this is why most good lithium batteries require BMS"s (battery management system or boards) that monitor temps and upper/lower charge
loads....without that, one shouldnt be using them.
As far as the fire part...not really true either. A lithium battery fire starts with what we call a "thermal runaway" meaning we cant keep the
batteries in the thermal position they like and they start to heat up.....if we can cool them off we control/cool the runaway....if we cannot the cell
expands and them if not cooled the gases in the cell escape leading to over oxygenation of the inner cell chemistry and usually a flash ignition. Of
course if anything flamable is within it it ignites as well but if nothing is near the cell will burn till it is cooled, not extinguished because it
cannot be....once cooled it becomes fairly stable again.
Fire departments will determine the risk verses water requirement.....so if they have a fire hydren handy they will
usually try to cool it down and snuff it....if not they will just let it burn.
If you look at people installations that usually tells you if they understand the battery or not.....lithium battery in a wooden box, in a wooden
compartment, under a wooden trailer floor.....you get the picture. So moral of the story....if you understand them and know how to work with them the
risk is no worse them a flooded battery but if you dont your playing with fire.....lol.
--
Rich Mondor,
Brockville, ON
77 Hughes 2600
> I created many Ecell worksheets to play with the numbers, and I will admit I am not perfect but I am getting some
> pretty good numbers that compare to working systems.
>
> My original comment was an attempt to help the user understand that SOLAR is a balancing act between the panels, batteries and the load.
> One scenario is where you may have a high count of solar watts which allows you to run some appliances during the sun hours
> while the batteries maintain charge.
> Another scenario is where you charge the batteries during the day and use the battery storage in the evening, requiring more batteries.
> The scenarios go on and on, it is all a customizing game to the use you have for the system.
> No one system is the same.
>
> My only comments on the batteries is they need something charging them, solar, vehicle alternator, generator or all of the above.
> Recent reads have come up with information that says that even though you CAN use the power in a battery and run its level down, IDEALLY, you want
>
> your battery levels high, near full.
> We had lead acid batteries in battery banks that would last 25 years.
> the Lithiums, and i am not going to get into an argument over these new batteries, but they have concerns that no one seems to
> consider. All that is heard is they can last longer and discharge further. I will say that is true, but, they don't like
> that deep of a discharge and every deep discharge is taking some life away from the battery.
> Also, NO BATTERY likes High loads for extended periods. Besides shortening the life of the battery, extreme high loads will find your
> system weak spots, usually connections, and they will get hot or burn. That is why I mentioned that time measure formula some kind
> person offered here at GMC net at one time, it is a loose figure to work with,
> but it is close enough to get an idea of what you are working with.
>
> IDEALLY, the batteries like low loads of 5 to 10 amps. You start to get high loads from the batteries, you need more batteries
> to share the load.
>
> Running the inverter is expensive on your battery power. at 12v dc, its a factor of 10. 20 amps of 12v dc into the inverter
> will supply 2 amps of 120v AC. The normal roof top AC is plus or minus about 9 amps, which would be 90 amps from the battery/hr.
> So that is not likely to happen as physically, the GMC does not have enough roof for panels or space for batteries to support that.
>
> The RV Nomads have taken to home windows units which run at about 3-4 amps/hr to run. This translates to 30 to 40 amps/hr of 12v dc into
> the inverter, still requires an extra panel or two and one or two more batteries, but it can be done.
>
> One important thing to keep in mind is if you draw high amps from the Lithium batteries, they start to get hot. That should be a warning
> but most don't understand. The article I read said that if those components, and that chemical mix begins to ignite, that battery
> fire is very difficult to put out, and you cannot use water on a lithium battery fire. If the fire department finds out there are
> lithium batteries involved in a fire, they become much more cautious about attacking that fire. So much so you may lose your rig.
>
> This is the main reason that batteries, including Lithium batteries, should be planned to supply low current loads, within reason, to the system
> including the inverter.
> Keeping the current loads down extends the battery life and runs at a much safer operating margin.
To be honest with you it depends on the chemistry of the lithium battery....most of them on the public market are of the safer variety and are quite
safe if not over exerted. The problem is people dont understand that not only high discharge rates affect lithium ion batteries also high charge
rates.....this is why most good lithium batteries require BMS"s (battery management system or boards) that monitor temps and upper/lower charge
loads....without that, one shouldnt be using them.
As far as the fire part...not really true either. A lithium battery fire starts with what we call a "thermal runaway" meaning we cant keep the
batteries in the thermal position they like and they start to heat up.....if we can cool them off we control/cool the runaway....if we cannot the cell
expands and them if not cooled the gases in the cell escape leading to over oxygenation of the inner cell chemistry and usually a flash ignition. Of
course if anything flamable is within it it ignites as well but if nothing is near the cell will burn till it is cooled, not extinguished because it
cannot be....once cooled it becomes fairly stable again.
Fire departments will determine the risk verses water requirement.....so if they have a fire hydren handy they will
usually try to cool it down and snuff it....if not they will just let it burn.
If you look at people installations that usually tells you if they understand the battery or not.....lithium battery in a wooden box, in a wooden
compartment, under a wooden trailer floor.....you get the picture. So moral of the story....if you understand them and know how to work with them the
risk is no worse them a flooded battery but if you dont your playing with fire.....lol.
--
Rich Mondor,
Brockville, ON
77 Hughes 2600
I'd take the watt values listed with a grain of salt - f'rinstance the microwave is listed at 750 Watts. Mine is a 1000 watt microwave, if it can
make a kilowatt of RF energy off 750 Watts of utility energy, I can sell it for a LOT of money.
Simple look at the patent plate and will tell you the appliance's power use in watts. Also remember things with a motor in them (Icebox,
Airconditioner)take a large surge current when turning on.
Add some leeway to the total to make up for this.
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
make a kilowatt of RF energy off 750 Watts of utility energy, I can sell it for a LOT of money.
Simple look at the patent plate and will tell you the appliance's power use in watts. Also remember things with a motor in them (Icebox,
Airconditioner)take a large surge current when turning on.
Add some leeway to the total to make up for this.
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
