Thread: Deep Cycle 12V Caravan Battery

I got given one of these the other day to compliment the 12v system we run in our hut. Problem is its dead flat and modern home-use battery chargers Ive tried dont like it
Anyone know if this is recoverable or is it a visit to the scrap metal buyer
Thanks

probably scrap, deep cycle do not like dropping too low in charge, meant to be kept topped up all the time, I have just replaced my caravan one, ouch!

Originally Posted by Bos

I got given one of these the other day to compliment the 12v system we run in our hut. Problem is its dead flat and modern home-use battery chargers Ive tried dont like it
Anyone know if this is recoverable or is it a visit to the scrap metal buyer
Thanks

You know where the scrap guy is in behind New World
They buggered
But still with taking to him as I have done with my ex Solar Banks

once they hit dead flat the plates are sulphated and they will never get back any significant capacity

Originally Posted by Bos

I got given one of these the other day to compliment the 12v system we run in our hut. Problem is its dead flat and modern home-use battery chargers Ive tried dont like it
Anyone know if this is recoverable or is it a visit to the scrap metal buyer
Thanks

Try connecting it up to a small 12 volt trickle charger, One without the brain that tells itself the battery is fucked. After a day or two it may take just enough charge to then be recognised by the smart charger. Even try connecting it to a medium sized solar panel (50-100 watts).

I have several car batteries that were classified as fucked, that I have running energisers around the farm. Connected up to a 120 watt panel with charge controller, they have worked fine for another 6 years. Still working today.

Appreciate all the comments and advice.
As it was given to me, got nothin to lose in trying to restore it.
I was told that a 24v charge into it for the first 12 hours would restore it enough to then handle a 12 v charger. At any rate, I'll give a few of the above options a go and see what happens

Second XR500. Old school charger that doesn’t know it’s stuffed is the way to go.

You can blow the sulphide off by giving a blast of 240, but it isn't in any manuals and you need to know the supply protection as well.

Old school wound chargers are where its at. The modern plug in and forget units, won't like it. Use a old one to bring it up, then plug in a new unit to keep it up.

Originally Posted by ONYVA

probably scrap, deep cycle do not like dropping too low in charge, meant to be kept topped up all the time, I have just replaced my caravan one, ouch!

I thought that’s what deep cycle batteries were designed for, discharging a lot before recharging (though not discharged too low or left flat)

Originally Posted by mimms2

NO!

if you do that, do it in the middle of a paddock and video it though!

OK Probably a "no" then

Ive found that if you have a charger that has a supply voltage setting on it leaving a battery hooked up for a couple of hours on that setting has kicked them back into life most of the time after a couple of hours on the supply setting disconnect and charge as normal

Originally Posted by Bos

Appreciate all the comments and advice.
As it was given to me, got nothin to lose in trying to restore it.
I was told that a 24v charge into it for the first 12 hours would restore it enough to then handle a 12 v charger. At any rate, I'll give a few of the above options a go and see what happens

Err no. If its a flooded deep cycle 12 volt battery putting it onto 24 volts will just boil off all the battery acid and fuck the battery properly. I HAVE put a seemingly dead 12 volt deep cycle onto 24 volts, but only till the ammeter showed it was taking a charge (15-30 min). Then back onto the 12 volt program.

If its a more expensive gel or AGM, the battery will simply start bulging (hence Mimms2 wanting a video taken) or squealing. The resultant gas bubbles in the gel push the gel away from the plates, and that part of the battery can no longer hold a charge. So your 100ahr battery rapidly becomes a 25ahr one.

I've always wondered about those desulphaters??? as that's the untimely end to most batteries. Sulphation.

I have on occasion bought deep cycle batteries from a battery restoration guy in Otahuhu, he has some little gizmo hooked to all his batteries as part of the restoration process.

3 weeks of pretty much continual crap weather (save for about 2 days of sun) have meant the house battery is getting down. Cranked up the generator to give it a birthday: I should have recorded the sound, made the Lister really get down and boogie with the charger on 150 amps@60 volts.

Best not try that on your little deep cycle battery, it may just shit itself! (House battery weighs 750 kgs)

At the moment I have my hydro feeding my main battery and my inverter off that feeding the solar fridge battery by charger.