Dead Battery after 6 Months???

[grotto69]

Went to drop some stuff at the RV and when I went to turn the engine over nothing. The battery was totally dead. What in the world? How does a battery go dead after 6 months? We just bought our FR in November and just got back 3 weeks ago from a long trip.

Is something trickling down the engine battery that I don't know about? Is that something that can be diagnosed easily.

The cool thing was the Battery Boost button worked like a champ and was able to get her started.

Any thoughts here would be appreciated.

Grotto

[SKnight]

First step is to get it charged up. Once you get power back to it walk around and check every light, closets, basements, everywhere.

If no lights are on and you don't find anything else on, then it depends on how mechanically inclined you are.

Remove a battery cable, clip a regular test light between the battery and the cable. If it lights up, you have a draw. Then, go to the fuse panel and start pulling fuses until the light goes out. That circuit has the draw.

The lamp element might barely glow, which is normal with computer memory circuits, but anything over .1 of an amp will cause it to light up pretty well and that's what will kill a battery.

If there's no draws then once charged up I'd have it tested. It's built by men, it could just be a bad battery.

[Herk7769]

Today's vehicles have A LOT of parasite draws, from clocks to radios to computers. If you can not drive the vehicle for a 100 or so miles a month, plan on removing the batteries to a warm garage for the winter.

[camaraderie]

Herk has it almost right! Batteries lose less in the cold than in the heat in terms of self discharge...but Parasitic loads will definitely drain a battery and kill it over time...sometimes a very short time.

Charge your batteries fully then leave in the coach and the cold...and remove the negative wire or buy a battery disconnect switch which is more convenient. They will still be over 1/2 charged 3 months later..at which they will need to be recharged. This applies to House and Chassis.

It sounds though like your batteries must have been fully charged just 3 weeks ago...so that sounds like a fairly significant parasitic drain or a defective battery.
To check for a parasitic drain...use a Clamp meter on your positive battery wire when everything is turned off and see how many amps are flowing.
Just a 1/2 amp draw, 24 hours a day means 12 amp hours a day and about 10 days to a dead battery. The solution is to start pulling fuses until the draw disappears and then you'll know where the problem lies. Easiest way is just to get a disconnect switch.
$5 bucks at Walmart

[grotto69]

Originally Posted by camaraderie

Herk has it almost right! Batteries lose less in the cold than in the heat in terms of self discharge...but Parasitic loads will definitely drain a battery and kill it over time...sometimes a very short time.

Charge your batteries fully then leave in the coach and the cold...and remove the negative wire or buy a battery disconnect switch which is more convenient. They will still be over 1/2 charged 3 months later..at which they will need to be recharged. This applies to House and Chassis.

It sounds though like your batteries must have been fully charged just 3 weeks ago...so that sounds like a fairly significant parasitic drain or a defective battery.
To check for a parasitic drain...use a Clamp meter on your positive battery wire when everything is turned off and see how many amps are flowing.
Just a 1/2 amp draw, 24 hours a day means 12 amp hours a day and about 10 days to a dead battery. The solution is to start pulling fuses until the draw disappears and then you'll know where the problem lies. Easiest way is just to get a disconnect switch.
$5 bucks at Walmart

WOW! Now that is a nice solution with the disconnect switch. Thanks so much. I love these forums, so many great ideas!!

[Gem Hunters]

My 2014 FR3 came with a battery disconnect switch. It's located at the top of the entry steps on the left hand side near the floor.

[Bobb36]

Originally Posted by Gem Hunters

My 2014 FR3 came with a battery disconnect switch. It's located at the top of the entry steps on the left hand side near the floor.

This only disconnects the coach batteries

[Phil57]

On the Berkshire there is a disconnect for both coach and chassis located next to the batteries. I would think they would put them on the FR3 also. I think most MH have them.

[Albert1950]

One of the things I want to do this weekend is measure what drains what and when. I will post my findings.

[wjpelka]

Harbor Freight has 2 devices that will tell you volts and amps and the are about $12 to $15. One is 30 amp max and other is 20 amps max. I bought the 30. Pull the fuse from the circuit and install it into device. Then plug device into fuse holder and read Volts and amps. I bought one yesterday and haven't tried it yet. But it will be a great help to locate these drains without having to buy an expensive clamp on ammeter. But I have 2 already, other people might not. Retired Electrician who loves tools and gadgets...

[johnpisue]

Thank you very much for the pictures wjpelka. This really helps.

John

[camaraderie]

WJpelka...I found 3 harbor freight $12 ish meters (all with Cen-Tek brand) but all only do AC current..not DC. Is this what you were talking about or something else? If you've found something cheap that will do AC/DC current...please post the stock # or brand/model as that would be very helpful to a lot of folks I think!

[camaraderie]

Ahh...never mind...I see you were talking about this item:

Very handy ...but only for checking fuses. Will pick one up on my next visit to my favorite "toy" store! Thanks.

EDIT ...Item #'s are item#67725and item#67724

[wjpelka]

I bought the 30 amp and will get the 20 next time. The 30 is for most of our fuses on the FR3 but the 20 will cover the smaller ones. I'm glad you found it and I should have listed the item numbers. I'll do that next time...