Flat battery

In my experience, if a battery has fallen as low as that it is well and truly goosed. I’d be careful leaving the likes on charge as they can overheat and even explode. Please take care.

You should check your charge control, as it looks like it has let your battery discharge back to your solar panel

Had it hooked up to a charger for 24 hours and have disconnected it and have been checking regularly and it’s holding 13.7v.  Will see it it’s stabilised 

mickysf, 

I'm a bit confused by "I’d be careful leaving the likes on charge as they can overheat and even explode. Please take care." I'm on my fourth Van in 20 years. Three have had batteries fitted and each whilst garage stored has been left hooked up and on charge 24/7 when not being used. 

kalamitty55,

some intelligent chargers have the ability to bring heavily discharged and apparently knackered batteries back to life. If problems persist and your charger is up for replacement then look at CTEK.

Colin

It shouldn't hold 13.7v for too long...remove the charger(!) and check in the morning.

you're looking for 12.7 or 12.8 volts as fully charged.

if you don't need it straight away, keep checking over the course of a week or more....

Just a word of concern, no more, I have personally witnessed three batteries over 40 years which have caused issues for their owners, one particularly dangerous, even with so called smart chargers being used. One exploded, one over heated and the third, mine, gassed into the habitation area setting off the CO alarm in the middle of the night. Hence the care I suggested. 

Too late to edit but the gas from the faulty battery setting off the alarm was hydrogen (not carbon monoxide) and some hydrogen sulphide judging from the smell which was the giveaway as to the origins. The battery had shown no real issues prior to this, just a tad flat on taking out of storage at 12.5volts. Only on hooking up on site some 10 hrs later did the ‘alarm bells ring’ and the episode start. I do hope this contribution helps.

 It sounds like this is not a one size fits all situation.

I know my van is fitted with a Schaudt CSV409A unit that incorporates a 3-stage charger. It also has a booster to regulate the charging voltage from the tow car. It feeds into a 95A/hr AGM battery

The unit has three protection circuits, namely overtemperature, overload and short circuit.

It is designed to be permanently left on and incorporates a trickle charge facility that automatically cuts out at 13.8v. 

Colin

I think so Colin, my Sargent system also has those protections too. With the one which exploded it was a neighbouring caravaner on site, thankfully it blew during the day when they were out. The battery was in a box in the floor and it blew the lid off spreading acid around the van. Not a pretty sight and so lucky it didn’t happen during the night as their dog slept right over it on the floor. It later transpired that the battery had depleted in storage and that the dog had only just started sleeping in that exact position. I now wonder if heat attracted the dog to that exact spot.

thanks for all replys,  once i charged the  battery up,  i have left it on the worktop in garage,  it staying at 13.7v  i am in no rush to put it back in the caravan as we wont be using it if at all due to wife fracturing her back and recovery is slow so will see if she's fit enough by april otherwise i'll sell it for easter,  to get back on track,  i always hookup the van but i left it disconnected as the solar was working but with the snow on roof i think the alarm has drained the battery and when i went to check there was no power,  i will probaly get a replacement battery just seeing if i can bring this one back to life.