12v House Battery Problem

[NR4A]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">- Checked all cells with a hydrometer. All good.

- Plugged in shore power overnight and then disconnected the house batteries. At the beginning, one was 12.75v and the other 12.82v. 3 hours later, one was 12.84 and the other 12.97. This tells me that they are being charged and can hold a charge on their own.?
- Pulled the wires off of the pop out circuit breakers one at a time and with a light probe tester in series at the battery. All seemed fine....very slight light...probably the propane checker and dash radio memory?

got these readings at the electric control panel of the coach at the times indicated:
1448: 12.7v
1630: 12.7v
1830: 12.3v
0800 (Sun): 10.3v!!!!! </div></BLOCKQUOTE>

It seems like you figured out the 1st problem with the hydrometer. Your batteries are charged if you are reading high specific gravity per cell. So far, so good.

I had a Fleetwood 5th wheel and couldnt find the converter. I eventually turned everything 12v on and listened around the coach for a fan motor noise. Found the fan motor noise coming from the converter mounted under the floor of our bedroom. Who'd have thought(?)

I would invest $15 in a multimeter at Wallyworld as it will offer more information than a test probe light. It will give you an accurate value of current draw per device or breaker.

Something happened between 6:30pm and 8am but it couldnt have been internal to the battery - perhaps external in the coach? Heater? Refrig running on DC?

got these readings at the electric control panel of the coach

What does the voltage measure at the batteries? Maybe you are having electric control panel issues after all and your batteries are fine. When you read the 10.3 volts, what does your hydrometer show?

Ive run into situations chasing electronic problems and found the diagnostic equipment I was using was at fault and there was really no problem at all with what I was trying to diagnose.

Just a thought.

[John_Canfield]

Get the batteries load tested. If your batteries are original equipment (circa 2001) their useful and trouble-free lifespan is over.

[Belgique]

Thanks guys. I'll try some of these new things (John, the batteries are about 6 mo old and have been load tested.)

I have a digital multimeter but don't think I know how to use it properly.

I put it in series with at the 12v breaker panel (one lead to ground and the other to the wire that would nornally plug into the breaker.) I note on most of them that I get 12v +/- when the appropriate light switch is toggled. On a couple there is 12v there ALL the time...could this/these be the culprit? One of these is the propane detector so I know it will always have 12v. But if it is supposed to be a light circuit then there should not be 12v there all the time, right?

I'm thinking that I should measure amps, but don't know how to do that...when I flip the meter to DC amps I get 0 on any of these.

Again, thanks guys. Maybe this thread will be useful in the future for others so it is not a waste, I hope. Steve

[Thudman]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I cannot find the coverter/charger Confused. The list says I have one ("AC/DC Elect Dist System w/remote 45amp converter/charger") </div></BLOCKQUOTE>


Steve:
In my previous 2000 Suncruiser 35U, and in my current rig, the converter is on the floor, beneath my stove/cooking range. If I pull out that bottom drawer (in my case, I had/have an oven & drawer beneath it), it's there on the floor, plugged into a 110V dedicated outlet (Mine is a Parallax Pwr Supply/Magnatek Model 7445; 800-443-4859).

Thudman

[John Hilley]

Actually, when you made your 12v measurements, you made a parallel connection. To measure current you use a series connection. You must disconnect the wire from the load side of the breaker and complete it by using the meter probes. One to the disconnected wire - one to the load connection on the breaker. You must insert the probes into the proper jacks for current (amps) measurement. Most inexpensive meters won't measure a very large current, use the highest current measurement on the meter.

[Belgique]

Thudman: I just found the converter after reading the schematics carefully and was coming in to edit my post when I saw yours. John: What you described is how I think I had it set up: aligatored the black lead to the ground bar and plugged the red lead into the unplugged wire (the breaker not in the equation at all). But, got no amp readings.

I'm about to give up on this sucker and just run the genset if we can't plug in

On Edit: to respond to a previous question...when the energy panel says 10.2v, I disconnected the batteries and one reads 10.5v and the other 11.15 (no load...just a simple digital multimeter).

[Don-Savannah, GA]

When using the meter to check amp draw you would need to connect the red meter lead to the wire you removed from the breaker screw, the black meter lead connects to the breaker screw. (I may have that backwards so if the meter shows negative you need to reverse the red and black leads). That means the meter is in "series" with the current flow. An anology would be putting a valve in a water line, you cut the line and put the valve in series with the pipe.

[Belgique]

Just want to thank all of you for your help. I've run out of time to pursue this further since we're jacks up Wed at 0'dark'30 for 2 months. Sure I'll have some time to pursue this on the road using your tips and I can surrender to a dealer (RV dealer, that is )in Vegas if need be before we go SOB.

BUT, I WILL post the ultimate findings for the benefit of those in the future.