Community Forums

rdotson0 · 05-04-2015, 06:36 AM

There is a factory?/dealer? installed solar panel on roof of our 05 Meridian Itasca 36G. It appears to be wired, so that it continually charges batteries. Problem is that with this continual charge going on, it cooks (causes to explode) batteries.
Is there anyway to disconnect or turn off solar panel charging? We have not been able to figure out. Just took motor home out of storage, and it had the cooking battery problem when stored. We have put new batteries in and everything is working and starting, but don't know how to stop continuous charging. Could problem be with inverter/converter?
Help is needed to avoid lots of money.
thanks and may God bless,
BOB D.

**Petro** · 05-04-2015, 07:16 AM

Bob;

You did not indicate how big the solar panel is. If it is like mine it is there to keep the batteries it is attached to from going dead. Mine is not big enough to cook the batteries. You did not indicate if your rig is plugged in 24/7 while in storage. If you do not have a 3 stage charger I would suspect that as a cause of your battery problem. I have a inverter/charger that is a 3 stage and I leave it plugged in 24/7 all year and have no battery problems. Keep us posted on the solution of your problem.

Good Luck;

Don

krivanj · 05-04-2015, 07:24 AM

If the solar panel isles than two square feet or so, it is not strong enough to cook your batteries. If much bigger than that, you need a controller for it. You don't say if you leave the couch plugged in for storage, but if you are in the frozen north, and you don't leave it plugged in, I'm guessing maybe the batteries lost charge and then froze, which would crack case and look like an explosion had occurred. Your converter inverter is probably similar to ours, yours being a Meridian, so,probably a three stage charger, so if left plugged in, it should have been fine.

Knightab · 05-04-2015, 08:22 AM

Agreed, I don't think you could get a panel big enough to cook the battery if it is installed by the dealer. You have a possible converter issue. If the panel is that large you need to put a controller on it. If you want it disconnected just look for a smaller wire connecting to the battery post.

TQ60 · 05-04-2015, 08:50 AM

Not enough information but it does not take much to cook the batteries...

Think "easy bake oven"...

They make cake with a light bulb.

A battery in float is expecting no more than about 0.1% C in charge current where C is the labeled capacity at the 8 hour rate.

So if for example you have a 200 amp hour battery and using simple math...

C=200
1% C=2
0.1 %C =0.2

Float current should be 0.2 amps max

Float charging is when battery is fully charged...some call it trickle charging but that is different conversation.

So it takes little current at the battery to cook it...over time.

Many cannot measure this tiny current but measuring voltage with an accurate meter works just as well.

13.5 is generally accepted float voltage but the battery data sheet will have voltage specific to your battery.

Converters usually cook faster and if in long term sunny unattended storage uncontrolled solar will cook them too but at a slower rate.

Flooded batteries can have water added to maintain them but VRLA/AGM will be toast.

Imurphy907 · 05-04-2015, 11:36 AM

Even a 100 watt panel ties direct to the battery will kill em.

Any panel should be connected thru a controller. And have a fuse, breaker and disconnect device for safety. I would call the MFG/dealer and ask them how its wired up. If there is no controller for $200 you can add one and have it working properly. You may even become addicted to solar like many of us. I find it hard to walk past the meter and not look to see my SOC and charging amps. Its like crack to me.

MotorPro · 05-04-2015, 11:42 AM

How big a Panel? Most factory panels couldn't over charge a double a battery much less a coach battery.

tednruthy · 05-04-2015, 12:41 PM

I am very surprised that no one yet asked if the coach was stored inside for the winter. If so and out of any sunlight the solar could not have hurt the batteries by charging. BUT may only if the solar connection caused a discharge due to unlikely bad/shorted solar panel or wiring. I would suspect frozen battery(s) unless the coach was left plugged in. If left plugged in I would suspect the charger/converter or Inverter combination whatever. MORE information is really needed.

Knightab · 05-04-2015, 01:06 PM

Most factory installed solar panels I have seen are 15 watt, at the absolute best you could get 1 amp in ideal sun, we are talking winter solar. I don't believe the solar was the problem. The solar panel would be doing good just to keep up with what that battery loses in a month. I suspect, converter overcharging, freezing or dry battery and as said if it is stored inside all bets are off on the solar

Redapple · 05-06-2015, 10:58 AM

Quote:

Originally Posted by Imurphy907

Even a 100 watt panel ties direct to the battery will kill em.

Any panel should be connected thru a controller. And have a fuse, breaker and disconnect device for safety. I would call the MFG/dealer and ask them how its wired up. If there is no controller for $200 you can add one and have it working properly. You may even become addicted to solar like many of us. I find it hard to walk past the meter and not look to see my SOC and charging amps. Its like crack to me.

This is where I would start. Do you have a charge controller? If so how is it tied into your system and is it working properly?

Good advice from lmurphy...