TV and House Battery

[edgar t. kremer]

The Sony might have a minimum allowable input voltage. If the voltage drops below
that point the unit will not function. One way to ascertain this is to use a
variable 12v power supply & lower the voltage to see if the Sony cuts off.

Batteries:
The best way is to use an ammeter in series with the converter & batteries. The
nasty way is to use a battery hydrometer. You can also measure the battery
terminal voltage with the converter turned on. Battery voltage should be approx.
13.6v to 14.2v. Turn the converter off & turn on a few 12v lights for a few
minutes. This will dissipate the surface charge. Battery voltage should be approx.
12.6v. However, a defective battery can still show good terminal voltage & not
sustain a good charge.
The Coast Guard will not accept battery voltage monitors as an indication of
battery charge for this reason.

> I have two things that concern me.
> 1. A 8" AC/DC Sony that plays fine when on AC. And it only comes ON sometimes
> when on DC. It is hooked up to a Winegard Antenna on the roof.
>
> 2. I have 2 Interstate batteries (deep cycle) hooked up in parallel. I really
> can't tell if and when they are charging. I leave GMC hooked to a 20 AMP
> source most of the time. I believe that they are charging slowly with the
> Generator running and when the GMC engine is running. Anyway to tell for sure?
>
> Thanks,
>
> Gene '77 PB

 

[mark grady]

> I have two things that concern me.
> 1. A 8" AC/DC Sony that plays fine when on AC. And it only comes
> ON sometimes
> when on DC. It is hooked up to a Winegard Antenna on the roof.

Check the supply voltage and ground where the TV connects to living area
power.
Many 12v powered sets have a low voltage protection circuit and will turn
off if there is less than ~10-11 volts. That's one thought.

Another way to test -- take the TV to another source of power, like your
car.
Doesn't have to get a picture, but does it come on, stay on? If so, you may
have a wiring problem in your coach that's providing low voltage to your TV.

Testing the TV on another source of 12v power is a sure way to know it isn't
the 12v power side of the TV, since it works fine on 110 AC.


> 2. I have 2 Interstate batteries (deep cycle) hooked up in
> parallel. I really
> can't tell if and when they are charging. I leave GMC hooked to a 20 AMP
> source most of the time.

If your 12v converter is working, they should be charging. What does the
voltmeter show on the monitor panel by the door? If less than 13.8 volts,
they aren't being charged.

>I believe that they are charging slowly with the
> Generator running

In theory, yes, in reality, probably not. The genset doesn't produce real
'accurate' AC. The factory charger likes pure, 115vac at exactly 60 cycles.
Tough to provide that with an Onan. You should have that when you're plugged
in.

How old are the batteries? I recall many on the list conclude that ~3-4
years is the life of the living area batteries. They sulfate and loose
capacity due to constant charging from shore power, particularly when
charged by the 'dumb' factory issue ferroresonant charger. If you're
replacing your batteries, now is the time to consider a Statpower charger,
or....

Get an automatic battery charger from Sears or an auto parts store. Sears
had/has some nice chargers that do a very good job of prolonging the life of
deep cycle batteries. I have one I got several years ago for $45.

I *unplug* the GM factory charger, then hook this baby up to the 12v living
area power buss in the closet. It monitors the batteries, charges when
needed and shuts off when it isn't. Very cheap solution, and you can get
another year or two out of your batteries. I'm on my 5th year with a set of
6v golf cart batts, and they still have 80% or so of their original
capacity.

A charger like this doesn't have a lot of output, ~10 amps, but you can use
it for other stuff around your house when you've put your GMC in
storage/whatever.

Mine is model 141-264. I'm sure it isn't made any more, but look for one
that says 'maintainer' in addition to all the other features. It's charging
characteristics for 'float' charging are excellent.

> and when the GMC engine is running. Anyway to
> tell for sure?

Check it with a known good voltmeter. When you first start with a cold
engine, voltage should be close to 15 volts, then taper down to 13.8 as you
reach regular operating temperature.

Anything less than 13.8 means your Delcotron isn't charging. You'll get by
for a while, but someday...

Confirm that your monitor panel voltmeter is accurate, turn it on and you'll
soon find out if you're charging your batteries.

Hope this helps,

Mark