A few weeks ago my coach's batteries (coach is a 2009 fleetwood excursion 40x DP) were dead when I went to pull it out of storage . Completely dead - even the aux start would not work. Couldn't even get the genie going until we put a charger on it.I figured maybe i had left the inverter on (possible i guess...). Anyhow got it charged, running, and plugged in for a few days.It sat in storage again for a week and this morning, it would not start again. It wasn't completely drained, but it still wouldn't start without running genie (luckily i was able to get that started).I made sure I had nothing on at all before i put it into storage last week and I can't make sense of what's going on.The batteries are new (or so says the dealership where i bought the coach from; will need to double check), coach does have a solar panel, and the batteries are not turned off.Any thoughts on this. I'm not sure what could be causing the drain.

Try disconnecting the battery ground cable the next time it will sit for a week. If it starts ok when you reconnect the cable, the battery is good and there's a draw somewhere else that's pulling it down. The quick fix in that case would be a battery disconnect switch that installs on the battery terminal, but finding the draw would be the better answer. That can be a long process though, unless you have a good multi-meter on hand and know how to use it for load testing.

My guess would be the solar controller is not working and batteries are not being charged. If you do disconnect batteries, make sure you disable the solar first.

Need a lot more info to help. Age and type of batteries? How many amps does your solar charger put out? How many amps does your built in charger and how long have you charged from shore power? Have you checked your parasitic amp draw with everything shut off? Do you have a battery shut off switch? How are you checking your batteries to know they are fully charged? From your post it sounds like your batteries are going dead in a week after charging is that correct? Have you checked the water level in the batteries? If you reply to the questions you will get better answers to your battery problems otherwise you will just get guesses.

Of course once the batteries get drained down to absolutely nothing like described here they are damaged and will never be the same after that... Most often they need replaced when this happens...Sometimes a complete disconnect by removing the ground terminal is the best approach instead of relying on disconnect switches. A fully charged battery will sit fully disconnected on the shelf or in the battery box for a long time and not drain down or freeze up.Using a multimeter across the battery terminal is a great way to determine if they are being charged. The normal fully charged DC VOLTAGE of 12.6-7VDC will show an increase of 13.2. or 13.6VDC when being charged. Certainly takes the guessing out of the procedure using a multimeter...We watch our batteries like a hawk when using them and when in storage as they are just too expensive for me to not do this...Roy Ken

We bought a brand new coach from a dealer (with 'brand new' batteries). Within six months we realized the problems we had were directly attributable to the batteries - they had been misused so much on the lot that they wouldn't hold a decent charge for long.

Solar charger but still dead batteries | Good Sam Community

25 Replies

fourmat
Explorer
Feb 08, 2016
with a solar charger or with out it should hold for longer than a week. Either batteries are bad or you have some sort of draw. Easiest place to start is batteries most auto parts stores will load test for free.
Sam_Spade
Explorer
Feb 08, 2016
elhajj33 wrote:

I'm not sure what you mean the common setups will charge the house batteries when the engine is running but not the other way. ca you clarify?

You have a "truck" engine that makes it go down the road. That has a normal starting battery.....probably only one.

Then you have the 12 V supply for the "house".

When the truck is running, it will charge both sets of batteries.....unless you have a battery disconnect switch for the house batteries that is turned OFF.

When the generator is running, it will charge ONLY the house batteries.....probably. This assumes that you HAVE a generator in the house part; most class A's do.
elhajj33
Explorer
Feb 08, 2016
bsinmich wrote:
Wen my RVs are I storage the solar panels do nothing. The roof stops sun from getting to the solar panels.

It's in a storage facility, but not indoors. I'm outdoors, in Florida: plenty plenty of light :)
elhajj33
Explorer
Feb 08, 2016
Sam Spade wrote:

"over 12 volts" is not accurate enough.
It needs to be over 12.8 just to break even and prevent self discharge.

And the actual charging voltage should be measured at the batteries while everything is connected. With some controllers the voltage will change drastically with no load.

And lastly, the most common setups will charge the house batteries when the engine is running but NOT the other way.

got it, i'll have to measure the voltage at each individual battery during charging.

I'm not sure what you mean the common setups will charge the house batteries when the engine is running but not the other way. ca you clarify?

Looks like I'm going to have to charge all the batteries and test them individually or just take the coach in to have the batteries tested (the coach is going in on Thursday to replace the dishwasher, ATS and a TV, so maybe i'll have them do it then).
bsinmich
Explorer
Feb 06, 2016
Wen my RVs are I storage the solar panels do nothing. The roof stops sun from getting to the solar panels.
Sam_Spade
Explorer
Feb 06, 2016
elhajj33 wrote:
I am getting over 12 volts (I disconnected the batteries from the controller and measured the output side of the controller to day this)

"over 12 volts" is not accurate enough.
It needs to be over 12.8 just to break even and prevent self discharge.

And the actual charging voltage should be measured at the batteries while everything is connected. With some controllers the voltage will change drastically with no load.

And lastly, the most common setups will charge the house batteries when the engine is running but NOT the other way. If yours is set up that way, charging the house batteries with an external charger does NOTHING for the engine batteries and the parasitic load plus the self discharge can easily discharge them in 3 months time.

Applying a charger to the engine batteries overnight (is there really more than one ??)will probably bring them up enough to start it and drive to a shop of your choice to have them tested.
It is probably that they need to be replaced but not guaranteed.
RicJones
Explorer
Feb 06, 2016
They should be able to test the batteries to see if they are good or not.
Interstate is usually pretty good about taking care of their customers.
elhajj33
Explorer
Feb 06, 2016
Hey all, quick update on this. I checked the solar controller voltage and I am getting over 12 volts (I disconnected the batteries from the controller and measured the output side of the controller to day this)

Today, I came and the main batteries were at 9.7 Volts while the house batteries were at 12.7. This was through the battery test not through a voltmeter. This also was after yh coach sitting in storage for 3 weeks.

I couldn't get th coach started even with aux start. I did get the genset going and was able to charge the batteries.

I'm thinking the house batteries are ok. I might have to pull both main batteries and get them checked. Should I pull the house ones as well?

Also all the batteries are 1-2 yrs old. I wonder if there's any sort out f warranty (interstate batteries)
Jim
Explorer
Dec 22, 2015
There are so many parasitic draws on modern RVs that I wouldn't even bother trying to track them down. Like the radio memory and the safety circuits and the engine & tranni computers. And most of those bypass the salesman's switches.

I just disconnect the NEG cables on both sets of batts when I park and if it's going to be more than 3 days.

BTW, most optional solar panels, on top of the AC, are 8 Watt. Not enough to electrocute a flea.
jwmII
Explorer
Dec 22, 2015
Does your panel have a charge controller in the loop? Many smaller capacity panels do not use a charge controller but will have a diode to prevent back feed thru the panel during the dark hours. This back feed will discharge the batteries if there is not a diode or if it fails. Use your V.O.M. to check for a diode.