Battery flat post winter storage

Jan 20, 2022
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Hi all,
I went to collect our Coachman VIP460 this morning and the motor mover wouldn’t engage. Bit of fault diagnosis and found the battery was flat. I have a solar panel on the roof which is supposed to trickle charge the battery. The winter cover has a clear panel directly above the solar panel; it was not dirty, misted or obscured. The van is 3 years old and I’ve never had this issue over the previous two storage periods. Clutching at straws but the roof of the van was very wet, with a few dirty streaks/smudges. Battery voltage was 2.6. I’ve got it on charge and it’s currently got to 12.8.
Will it fully recharge? Any ideas on way it went flat?
As ever, best regards, Mark.
 
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Oct 19, 2023
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50/50 on whether it will recharge, at 2.6 Volts it may be beyond recovery but there is no harm in trying. As to why it went flat, more current was being drawn from it than was going in. Could be solar panel not charging or something left switched on that was drawing more power than the solar could supply. The solar power controller should tell you whether it's charging the battery (in daylight).
 
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50/50 on whether it will recharge, at 2.6 Volts it may be beyond recovery but there is no harm in trying. As to why it went flat, more current was being drawn from it than was going in. Could be solar panel not charging or something left switched on that was drawing more power than the solar could supply. The solar power controller should tell you whether it's charging the battery (in daylight).
Thanks.
 

JTQ

May 7, 2005
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As said having gone down to 2.6 volts, probably for days on end there is a risk it can't now ever be recovered, but worth a try though I would not put your chances remotely as good as 50/50.

It has been a dreadful winter lay-up season in respect to gleaning much solar energy, and if the van in question has any active alarm system that will have needed powering. A solar panel covered by plastic "window" is going to be seriously inhibited in gathering what very little energy this winter must have provided, it comes as no surprise it simply did not "work" adequately.

The battery being recharged up to a standing voltage of 12.8 volts is in itself pretty meaningless in the context here, what that is telling us is only it is as charged up with energy as its health condition now allows. In no way does that mean it has recovered the ability to hold a decent percentage of what it once was capable of holding; it could well be as fully charged as it can be, but now holding say just 10% of what it once could have held if reasonably healthy.
The highish current draw of using a mover will very quickly let you know if its state of health [its real life present AH capacity] is adequate for your needs, as that directly impacts on the voltage it can provide under load.
 
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As said having gone down to 2.6 volts, probably for days on end there is a risk it can't now ever be recovered, but worth a try though I would not put your chances remotely as good as 50/50.

It has been a dreadful winter lay-up season in respect to gleaning much solar energy, and if the van in question has any active alarm system that will have needed powering. A solar panel covered by plastic "window" is going to be seriously inhibited in gathering what very little energy this winter must have provided, it comes as no surprise it simply did not "work" adequately.

The battery being recharged up to a standing voltage of 12.8 volts is in itself pretty meaningless in the context here, what that is telling us is only it is as charged up with energy as its health condition now allows. In no way does that mean it has recovered the ability to hold a decent percentage of what it once was capable of holding; it could well be as fully charged as it can be, but now holding say just 10% of what it once could have held if reasonably healthy.
The highish current draw of using a mover will very quickly let you know if its state of health [its real life present AH capacity] is adequate for your needs, as that directly impacts on the voltage it can provide under load.
Thanks. I am braced for a new battery! Hadn’t thought of the alarm. Bit daft setting it really when under a cover on a super secure site!
 
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Thanks. I am braced for a new battery! Hadn’t thought of the alarm. Bit daft setting it really when under a cover on a super secure site!
The solar panel topping up the battery will easily cope with the drain for the alarm. It may also be a condition of your insurance to have the alarm switched on?
 

JTQ

May 7, 2005
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The solar panel topping up the battery will easily cope with the drain for the alarm. It may also be a condition of your insurance to have the alarm switched on?
As I said, an alarm needs powering so logically that has to come from somewhere, typically they get boosts from caravan leisure batteries.
, which might be the case for the OP. I was aware with one Coachman owner that definitely was the case in the as delivered build.
What is for sure, in the OP's case something has excessively drained the battery other than the batteries internal loss, which if the battery was healthy would be into months, so longer than a typical winter layup duration.

Solar systems "should" rather then "will" supply the drains of batteries during storage, but there are many possible reasons that can inhibited them even assuming it has no fault.
 
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Jan 20, 2022
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Mark,
I’m stating the obvious but are you certain everything was switched off before you left the van in storage? Eg fridge light , radio aerial booster on.
No signs of a little field mouse🙀
To be completely honest, I may have left something on but can’t find out until I get the new battery. Don’t want to apply mains power until I’ve confirmed the new battery. That said it would be unlike me; been caravaning for 25+ years. Not that that prohibits overlooking something though!
 
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The saga continues!

New battery fitted, all good. Apart from none of my internal lights work! Can’t see how this can be linked to the battery as the lights require mains power. Checked the fuses, all OK. All other electrical equipment working fine. Any suggestions?
 
Nov 16, 2015
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The saga continues!

New battery fitted, all good. Apart from none of my internal lights work! Can’t see how this can be linked to the battery as the lights require mains power. Checked the fuses, all OK. All other electrical equipment working fine. Any suggestions?
If the lights are on mains and your not using EHU, then they won't work. Or am I missing something again
 
Nov 16, 2015
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Sorry, should have said I’ve connected the mains.
Although you have 25 year +, You haven't missed a separate "Master" light switch, by any chance, I have done it before on my van.

We have had our van 11 years now, it was only last year I noticed all our lights are 12 volt, I thought half were mains powered.

I have also left the awning light on by mistake, when switched ON, by the switch, the Alarm does NOT switch it off.
 
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JTQ

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I am pretty confident Coachman would have used 12 VDC for most if not all the lights. Not mains via the EHU.
Does the water pump work, that will be 12 VDC?
If that does not work, then the 12 VDC system is not being powered, if it does then the fuse to the lights needs checking.

If pump also does not work, along with lights, then check any in-line fuse between battery and charger/distribution control system, as a first check.
The latter could also hint as to why the battery is found so depleted.
 
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I am pretty confident Coachman would have used 12 VDC for most if not all the lights. Not mains via the EHU.
Does the water pump work, that will be 12 VDC?
If that does not work, then the 12 VDC system is not being powered, if it does then the fuse to the lights needs checking.

If pump also does not work, along with lights, then check any in-line fuse between battery and charger/distribution control system, as a first check.
The latter could also hint as to why the battery is found so depleted.
Thanks for this. The Motor Mover worked so I’m guessing the 12V system is functioning, albeit I haven’t tried the water pump yet. The 5A fuses for the lights look sound. Why would they fit an inline fuse in addition to the main fuse board? Is that usual?
 

JTQ

May 7, 2005
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The mover will almost certainly not be powered via the 12 VDC, "system", but connected directly to the battery. Its current draw is too high for the wiring used to feed all the items serviced by the control distribution unit.

Yes it is normal, best practice, to have a fuse in the battery feed, so it is physically as close to the battery as practical, minimising the overall risks.
 
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Just checked the water pump, not working! I think you are probably spot on re the inline fuse, little did I know! Perhaps the current ‘surge’ when I fitted the new battery blew it? I guess it won’t be in the battery compartment but probably in the under bed locker adjacent to it?
 
Nov 16, 2015
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I have never had a battery fuse rupture, just on connecting the battery, maybe something has shorted out causing the failure. The fuse is normally very near the battery box, under the bench seat.
I don't know the solar panel system so maybe something there has caused a problem.
 
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