GMC battery

hsueh

New member
Dec 23, 1999
10
0
0
Hi,

One more question. What might be the possible cause that draw power
and drain my battery? I thought I turned every thing off.

Thanks.

James Hsueh
78 Royale
Fremont, CA
 
don't forget some sensor fans are on all the time also.

gene

>In a message dated 01/03/2000 4:05:12 PM Central Standard Time,

>
>> One more question. What might be the possible cause that draw power
>> and drain my battery? I thought I turned every thing off.
>>
>James
>
>That is the big question. Here are some things I have found. I have a
>CB that has the weather alert on it. It is on all the time. On my sob
>it will drain the battery in 10 days. If you have a new radio/tape player
>that remembers stations it is using juice all the time. Any toys that
>have digital numbers that stay lit. On the house side of things. The
>amplifier on the antenna is drawing juice if the red light is on. If you
>have a TV that has a remote on it ----it is using some all the time. The
>real battery killer is a fast start TV. If it is a 12 volt TV and the
>picture comes on instantly when you hit the remote-----those
>will eat batteries. Check any 12 V clocks or alarms. Check your
>reefer---some use 12V even when off. Now if you really want to get
>picky take the bulb out of your light fixtures and take an ohm
>reading across the two wires. I had one light fixture that somebody
>had used some sort of grease on the bulb. The problem was it was
>a conducting grease. There was some voltage leak to ground. One
>last thing. A friend of mine ask me to trouble shoot his SOB for a voltage
>leak. To make a long story short----if your reefer has a light in it pull
>the fuse or take out the bulb before you prop the door open for
>storage.
>
>Take Care
>Arch 76 GB IL
>
Genef -- 77PB/ore/ca
GMC MOTORHOME INFORMATION
mr.erf
http://www.california.com/~eagle/
 
This morning when I tried to start the engin, I found the battery was
dead, even the boost battery was dead also. AAA tow truch came
but can not jump start the engine. The driver said I need a new battery.

Most tow truck operators are fairly knowledgable, however I think
in this case further diagnosis is necessary before buying batteries.

"AAA tow truch came but can not jump start the engine"

While the batteries may be bad, If the tow truck cannot jump start
the motor there is something else wrong. Does the motor turn over
while being boosted?

If not I would check connections, battery, ground, starter etc. before
spending any money on batteries.

Good luck

Regards

Gary Zingle
1973 GMC 26 foot
- -------------------------------------------------------------------------=
- --
- ---------------------
Happy that winter has finally arrived in Edmonton.
I was beginning to worry I might have to mow the lawn in January.
At -25C that is no longer a concern.
- -------------------------------------------------------------------------=
- --
- ----------------------
 
Sometimes when they jump across the battery, they load it down and it wont
start. If you disconnect one of the battery connections and they can get it
started, and you cannot with the battery connected, you might have such a dead
battery that it should be recharged slowly, and it won't start with it in the
circuit.
al

>
> This morning when I tried to start the engin, I found the battery was
> dead, even the boost battery was dead also. AAA tow truch came
> but can not jump start the engine. The driver said I need a new battery.
>
> Most tow truck operators are fairly knowledgable, however I think
> in this case further diagnosis is necessary before buying batteries.
>
> "AAA tow truch came but can not jump start the engine"
>
> While the batteries may be bad, If the tow truck cannot jump start
> the motor there is something else wrong. Does the motor turn over
> while being boosted?
>
> If not I would check connections, battery, ground, starter etc. before
> spending any money on batteries.
>
> Good luck
>
> Regards
>
> Gary Zingle
> 1973 GMC 26 foot
> ---------------------------------------------------------------------------
> ---------------------
> Happy that winter has finally arrived in Edmonton.
> I was beginning to worry I might have to mow the lawn in January.
> At -25C that is no longer a concern.
> ---------------------------------------------------------------------------
> ----------------------
 
Well said

I added it to the battery section.

gene

>From what you say that the coach had be sitting 3or 4 years and these are
the same batteries that have also set the same time length it would be
better to replace them. For the chassis battery (engine starting) get the
biggest, highest CCA you can find. Walmart sells a 1000 CCA battery for
about $60. This size battery will provide a reserve starting power than
the lessor rated sizes.
>As for coach batteries it depends on the layout of your electrical system.
If you have the single big battery in the rear with a small one for the
onan most GMC'ers have change to 2 6volt golf cart batteries in series and
eliminated the starting battery for the onan, instead using the coach
batteries for starting. You should get 6 volt golf cart batteries of at
least 220 to 225 aH size. Interstate and Trojan are the most popular
brands, but I am sure that you may find batteries of the same rating and
Costco or other discount suppliers. The choice is yours. A site for great
GMC info is http://www.california.com/~eagle/
>
>You can get a lot of you questions answered by looking thru this site.
>
>J.R. Wright
>GMC GreatLaker
>77 Eleganza II
>Michigan
>
>
>
Genef -- 77PB/ore/ca
GMC MOTORHOME INFORMATION
mr.erf
http://www.california.com/~eagle/
 
>You should get 6 volt golf cart batteries of at least 220 to 225 aH
>size. Interstate and Trojan are the most popular brands, but I am sure
>that you may find batteries of the same rating and Costco or other
>discount suppliers.

Be aware that the different manufacturers recommend different depths of
discharge. For example, Interstate suggests discharging to 60% of capacity
at most with 50% preferred. On the other hand, Trojan specs to 80%
discharge as their recommended maximum depth of discharge.

Whether or not there is really a difference in practical discharge rates
depends on the battery chemistry and construction. Some batteries have a
modified plate construction with additional alloyed elements used to
change physical and electrical characteristics. Others have modified
chemistry for the electrolyte paste.

Typical life of deep cycle batteries vs discharge depth:

25% 2200
50% 1000
75% 550
100% 325

The bottom line is that there will be a "theoretically best" battery for
any given set of conditions. But, other factors like case size, battery
cost etc may cause you to make a different decision.

Henry
 
For all of you that have never accessed this site before, its invaluable for
the information that it gives on all subjects of RVing. Excellent parts on
batteries and chargers too!

http://www.phrannie.org/

and this on batteries. http://www.phrannie.org/battery.html

Follow it and you will not go wrong. You really need something like the
statpower 40 and remote monitor for your deep cycle batteries to get the
full use out of them.

>>You should get 6 volt golf cart batteries of at least 220 to 225 aH
>>size. Interstate and Trojan are the most popular brands, but I am sure
>>that you may find batteries of the same rating and Costco or other
>>discount suppliers.
>
>Be aware that the different manufacturers recommend different depths of
>discharge. For example, Interstate suggests discharging to 60% of capacity
>at most with 50% preferred. On the other hand, Trojan specs to 80%
>discharge as their recommended maximum depth of discharge.
>
>Whether or not there is really a difference in practical discharge rates
>depends on the battery chemistry and construction. Some batteries have a
>modified plate construction with additional alloyed elements used to
>change physical and electrical characteristics. Others have modified
>chemistry for the electrolyte paste.
>
>Typical life of deep cycle batteries vs discharge depth:
>
>25% 2200
>50% 1000
>75% 550
>100% 325
>
>The bottom line is that there will be a "theoretically best" battery for
>any given set of conditions. But, other factors like case size, battery
>cost etc may cause you to make a different decision.
>
>Henry
>
>
>
>
 
>Typical life of deep cycle batteries vs discharge depth:

>25% 2200
>50% 1000
>75% 550
>100% 325

>The bottom line is that there will be a "theoretically best" battery for
>any given set of conditions. But, other factors like case size, battery
>cost etc may cause you to make a different decision.

so Henry,
How about some kind of do-dad that would disconnect the batteries when they
get down to 50%. I know that something like that would save me a lot of
grief. I am forever running the house batteries dead

Terry & Diane Skinner
Webfooted in Washington
 
>so Henry,
>How about some kind of do-dad that would disconnect the batteries when they
>get down to 50%. I know that something like that would save me a lot of
>grief. I am forever running the house batteries dead


Tricky, but probably workable. The biggest problem that I see is accurately
determining the charge state of the batteries. There's some pretty funny
behavior during discharge that would fool a simple cutoff circuit.

Henry
 
>
>
>>so Henry,
>>How about some kind of do-dad that would disconnect the batteries when they
>>get down to 50%. I know that something like that would save me a lot of
>>grief. I am forever running the house batteries dead
>
>
>Tricky, but probably workable. The biggest problem that I see is
>accurately determining the charge state of the batteries. There's some
>pretty funny behavior during discharge that would fool a simple cutoff circuit.
>
>Henry
I have seen such a device for the coach ( or your auto) I just can't
remember where right now.
it is supposed to disconnect the battery before the charge gets too low to
crank the engine.


Jim
'73 Canyon Lands
Aurora, CO & Havre, MT
 
yep

called a battery buddy I think. supposed to save enough so you can get rig
started.

But I am not sure if it is accurate enough to stop at 50% and would you
want it to? On the engine battery,you should leave nothing attached to
the engine battery to run it down. On the coach, might just want a warning.

as the literature shows, the difference between a charged battery and a 50%
battery is .5 volts and that is only on a new battery. If yours are old
and of diminished capacity, would be less. You would have to make the
decisions at the .o1 volt level and the decision would be relative to the
100% charge level.

by the way, I have some lost family history in Havre Mt. do you do any
family history work ??

gene

>>
>>
>>>so Henry,
>>>How about some kind of do-dad that would disconnect the batteries when they
>>>get down to 50%. I know that something like that would save me a lot of
>>>grief. I am forever running the house batteries dead
>>
>>
>>Tricky, but probably workable. The biggest problem that I see is
>>accurately determining the charge state of the batteries. There's some
>>pretty funny behavior during discharge that would fool a simple cutoff
circuit.
>>
>>Henry
>I have seen such a device for the coach ( or your auto) I just can't
>remember where right now.
>it is supposed to disconnect the battery before the charge gets too low to
>crank the engine.
>
>
> Jim
> '73 Canyon Lands
>Aurora, CO & Havre, MT
>
Genef -- 77PB/ore/ca
GMC MOTORHOME INFORMATION
mr.erf
http://www.california.com/~eagle/
 
Hi All

Cruising Equipment makes a battery meter with a generator start output. It
monitors battery condition taking into account the Peukert Exponent of the
battery. (The higher the discharge rate the lower the Amp/Hour rating of
the battery.)

These meters are generally used for solar power and electric cars. Check at
http://www.cruisingequip.com/pages/emtr.htm

Dave

- ----- Original Message -----
From: "Terry & Diane Skinner"
To: "GMC Mail List"
Sent: January 05, 2000 11:03 PM
Subject: GMC: GMC battery

> >Typical life of deep cycle batteries vs discharge depth:
>
> >25% 2200
> >50% 1000
> >75% 550
> >100% 325
>
>
> >The bottom line is that there will be a "theoretically best" battery for
> >any given set of conditions. But, other factors like case size, battery
> >cost etc may cause you to make a different decision.
>
> so Henry,
> How about some kind of do-dad that would disconnect the batteries when
they
> get down to 50%. I know that something like that would save me a lot of
> grief. I am forever running the house batteries dead
>
> Terry & Diane Skinner
> Webfooted in Washington
>
 
>yep
>
>called a battery buddy I think. supposed to save enough so you can get rig
>started.

Also Priority Start and a few others as well.

>But I am not sure if it is accurate enough to stop at 50% and would you
>want it to?

The real problem is that any measurement of instantaneous current draw must
also adjust for the Peukert effect (higher current draw means less
available AH) and a few other conditions. Cruising Equipment does make a
monitor that they claim will adjust for all effects, but it doesn't have a
cutoff - just a genset start output. With the E-meter you would have to
select the exponent for the Peukert equation - not a big deal but one that
directly affects the accuracy of the meter. This all assumes a new or like
new battery. As the battery ages or is abused, equations change.

> On the engine battery,you should leave nothing attached to
>the engine battery to run it down. On the coach, might just want a warning.

I agree. OTOH, a Battery Buddy or Priority Start could be a good addition
on the starter battery only. I have to confess that when the question was
first posed I thought of the coach batteries instead.

Henry