Dead Batteries

grovelander · 10-02-2007, 09:36 PM

Here's a battery question. After driving for three hours, I parked over night. Next morning, all three batteries were dead. I thought use of the coach batteries wasn't supposed to kill the engine battery. Is there a defective part here? Also, there is an "on/off" switch in the battery compartment. What does it control? Thanks for the help.
GL

68 Overlander · 10-02-2007, 09:53 PM

GL,
Your tow vehicle should have an isolator. Most modern trucks do but if not I would get one installed.

grovelander · 10-02-2007, 09:56 PM

This is in my 345 MH. Is there an easy way to tell if the isolator isn't working?

Chaplain Kent · 10-03-2007, 03:11 PM

Welcome Grovelander.
I am not to familiar with the 345 but in my coach I have a battery "isolator" on off switch which turns off the starter battery. I turn the battery off only during long term storage. The coach has many trickle drains on it and this protects from those drains. In regards to your isolator, I have been told that they seldom go bad, further this would not really be the cause of the problem you are having. First thing I would check is the obvious, battery corrosion, can your batteries get a good charge? Second is your charging system, belts tight, alternator and regulator working correctly? third is the ability of your batteries to hold a charge. How old are they? What volt and amperage do they read when fully charged? Always look for the obvious first before seeking out those interesting things like battery isolators.
Good luck to you.

Geophilist · 10-03-2007, 03:36 PM

Grovelander,
Chaplain Kent has some good advice for you. You might also check if there is any water in your batteries. It is possible that your inverter/charger either boiled out the water, or went south and you just discharged the batteries. If you are hooked up to shore power and the 12v stuff in the coach is not working, then look hard at the inverter/charger. It could be a coincidence that all three went out at the same time. You could have something left on like a radio that took out the couch battery.

I have a digital volt meter that plugs into a cirgar lighter socket and will read the charge on the batteries. I move it between one hooked up to the coach battery and one to the house batteries. I can tell right away if the charger is on or the alternator is working as well as the state of charge on the batteries. They cost about $13 at auto parts stores.

Good luck in finding your problems.

Steve

ralley · 10-04-2007, 07:10 PM

I have a similar problem, which has been the devil's own work to track down.

Try the following:

1. Charge all batteries--take them out of the vehicle and charge them on a trickle charger.

2. Put them back in the vehicle, and hook them up.
3. Disconnect the positive battery clamps on both battery banks
4. Take a digital multimeter/voltmeter and read the DC voltage between the positive post on the batteries and the positive clamp.

If all your systems and switches are off, then you should get no voltage reading. If you get a voltage reading, then you have a short or a ground leak. If you switch to the DC amps reading on the meter, you should be able to read the actual amperage draw of your problem. Figuring how big a leak you have can help find the leak.

From what you say, it is likely that your problem is somewhere that you have both batteries hooked up to a single piece of equipment for isolation or charging--like the battery isolator, charger/inverter, or generator.

When you are successful in disconnecting the offending circuit(s), the amperage draw will go away, and you will have found your problem.

Good Luck,
Best,

R

str8strm · 10-11-2007, 05:55 PM

is close to you in Sun Valley, we store our 345s there and they helped us to isolate some drains we had when we bought our coach(s). The switch in the battery box turns off the house batteries but once we isolated the drains we do not have to use it anymore. Feel free to PM us for help--we love 85 345s! We also have a great person for upholstery if you need to update your interior

grovelander · 10-17-2007, 07:44 AM

Once I find some time, I will try out this good advice. Thanks.
GL

Chuckles · 10-24-2007, 01:23 AM

IF you have two batteries, are they the same age and size, is one pulling down the other? Try using them separately and see what happens.

Check the "Start Assist" solenoid is not shorted out.

Check the isolator if you still have one. that is a simple test with a meter. There should be zero volts with the engine/ignition off between the the House battery terminal and engine charger/alternator terminal.

I have fitted the Sterling "Battery-to-Battery charger. That replaces the isolator and improves house battery charging from the alternator.