Battery Keeps Going Down

[Gene H]

On my 2007 Four Winds Siesta the battery keeps gpoing down and I haven't been able to find the reason. I have looked for a light being left on but haven't found any on. The refrigerator is off and the hot water heater is off. Are there some other places I should be looking?

Thanks,
Gene

[cltkids]

I had a 2006 Daybreak and it would get drained while sitting around in the winter. Never did figure it out.

My 2007 Hurricane also developed a battery draw problem, but it occurred often. Turned out I had multiple bad cells in the house battery.

[MtManLee]

Start by making sure your water level in the battery is up, second charge battery and make sure all the cells are good, third check to make sure you have a good clean connected battery post, than I would start looking for what might be causing the draw. There are many things that run in the rvs like clocks, propane detectors, co2 detectors, and so on.

[Gene H]

I charged the chassis battery. I checked all lights by turning them on and then off to make sure they were all in the off position. I had the battery disconnect switch to turn off the auxillary battery. Nothing in the motor home appears to be on. I found nothing on the vehicle on (lights, radio etc.). I am unable to check the chassis battery because it is a FORD maintenance free battery. It has non-removable vent covers so I can't check the cells.

In the owner's manual it talks about a BATTERY ISOLATOR. If power is lost to the interior from the auxillary battery, check the breaker mounted on the side of the isolator solenoid under the hood. I haven't been able to find this breaker. Do any of you know where it is located and what does it look like?

[porscheracer]

I hate to say it, but you need to break down and buy a decent multimeter. An RV'er without one is as bad as a homeowner without a screwdriver. A multimeter will answer your questions - as opposed to trying to guess whether there's current flowing through that wire.

[Groveite]

Even your 12 volt stereo will draw a tiny bit...I disconnect the batteries for long periods of storage.

[Clay L]

If it's the chassis (engine battery) you are talking about, it will discharge in about three weeks or so because of the keep alive current required by the engine computer, transmission computer, ABS computer, dash radio and probably other items.

I use a "BatteryMinder" float charger that I connect when we are stopped for more than a few days. It can be left connected indefinitely and will keep the battery topped off without overcharging it.

[Gene H]

I used a multimeter this morning to check the voltage but I only checked it after charging the battery and not before. It was so dead the starter didn't even click when the key was turned. It had 12.5 volts after charging last night and still had the same this morning. The last time this happened was only 4 days ago. It lost the charge in 4 days.

I am thinking about running an electrical connection out to the carport where I keep the motor home and leave it connected. Is this a good idea to leave it always connected. The motor home can go weeks without being used.

Thanks to all who have offered suggestions on what may have been the problem.

Gene H

[GaryKD]

Gene,

Can you measure DC AMPS/miliamps with your multimeter? If so, it should not be difficult to trace down the offending circuit. Connect your multimeter and pull fuses for the circuits one at a time. When the draw goes away, you have the offending circuit.

If you have an intelligent charger that will go into float mode once the batteries are charged then you can leave the coach plugged in all the time.

However, it is not clear to me if your trouble is with the chassis or coach battery(s). If it is with the chassis battery(s), make sure the charger actually charges the chassis battery. Many coaches are wired so the charger charges only the coach battery(s).

Lastly, make sure the battery(s) is fully charged. Remove the +/- wires. Let the battery sit for a couple of weeks and take a measurment of DC volts. If you have 12.6V then the mystery draw is a likely source of the problem. If the battery is below 12.4, consider taking it to a local battery retailer and have them check the battery with their testing machine.

[Gene H]

Gary,

I checked the chassis battery this morning and it was down to 10.8V. It was still enough to crank the vehicle. I charged the chassis battery using a stand alone battery charger two days ago.

To check DC AMPS/miliamps as you suggested should the multimeter be connected in series with the fuse panel? I have never tried to check DC AMPS/miliamps before so I am not sure of the procedure.

I will be using the motor home soon so I won't be able to disconnect the battery for a couple of weeks to check voltage drop until I get back from my trip.

Thanks for you advice,
Gene H

[troth]

Gene H,
Do you have an inverter that is left on? That will run down your battery pretty good. It could explain why it went from 12.5v yesterday morning to 10.8v this morning.

Loosen & remove your + & - cables from the battery; do this in the dark or twilight. If you see a little spark when either cable terminal is removed or when they're reconnected, you've got an electrical draw from something in your coach.

Lastly, make sure there's no corrosion around any battery cable end or terminal, especially the grounds.

[GaryKD]

Hi Gene,
Please take your battery charger with you on your trip.

Go here for a short read on how to do this with meter leads. For a very long time I have used only an induction (clamp on) multi meter. It's amazing how much skill one can lose when modern technology is used.

[george henry]

I always take my battery charer with me in the motorhome and leave it in the strorage bin. A 10 amp quick charger. When I get to the site I plug it into the pedastal on the 110 volt oulet with the extension cord. that way when you are ready to leave you know that the battery is fully charge. my battery are only less then 2 years old , but I am not going to take a chance on not being able to start and leave from the camp site. only to have to call COACH CARE. been there done that . no more just go to Sears and buy yourself a good unit less then $50 bucks.

[Clay L]

Quote:

Originally posted by Gene H: I used a multimeter this morning to check the voltage but I only checked it after charging the battery and not before. It was so dead the starter didn't even click when the key was turned. It had 12.5 volts after charging last night and still had the same this morning. The last time this happened was only 4 days ago. It lost the charge in 4 days. Gene H

If the battery read 12.5 volts after charging all night the charger probably wasn't connected or wasn't working properly.
The charger or converter - whichever you used - should output 13.2 to 13.8 volts or so and that's what your battery should read immediately after charging.

The surface charge will be absorbed and the actual battery voltage can be measured but it takes several hours. Fully charged it should read 12.6 to 12.8 volts.
Some people recommend waiting 24 hours after charging to measure the battery terminal voltage.

Please note that for many converters and battery chargers it can take days not hours to fully charge a battery.