Thread: Deep Cycle 12V Caravan Battery

Originally Posted by XR500

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)

There was a time we had a briggs&bastard 5 Hp with 24 volt alternator to charge house battery...hold throttle wide open until it hits peak revs and then flick the switch for alternator, get it wrong and motor would stall instantly mid stroke.

Oh what I would have done to get a farm with decent running water.... Hard to come by in Pumice country.

I wish!!!
Nope. Our bore water comes from 200m down around here. Expensive hole for sure.

For power generation the big boys drill down 2000-2200m. The old 1960's Wairakei bores were only 200-500m deep.

Have got a wee bit of running water on the farm, but only enough for the ducks

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

Havent read past this, so someone else might've suggested the same: I've had good results connecting a large, fully-charged battery to the dead one, then a charger onto the good one for a couple of days. Once it accepts charge (and charges up), work it hard ie wind over something in 1stgear. Run it down a bit, then hard-charge again before putting into service. I have 2x 400cca batteries going strong a year after they were deemed scrap. This was advice given to me , specifically for gel-mat batteries, but worked equally well on the lead-acid. Worth a shot

Went to start the mighty Outlaw up, and dead flat battery. 2 volts. Gel. Smart charger didn't recognise it. So did your trick and jumpered it in parallel to a 200ahr I have at full charge. Overnight it rose to 10 volts. Now on trickle charge in the smart charger. Wonderful! Will see how it fares tomorrow at the Kuratau quad bike ride. Go the might ktm RFS 525 motor

Originally Posted by Phil_H

Well all I can say is that it is a good thing that I hadn't read all these replies before I had our caravan battery revived.

First time was about 4 years ago. Had it under cover and had left a light on inside. When we finally got to it some months later the battery appeared dead. Connected to my home charger and it told me that the battery was defective and wouldn't even try to put a charge into it. Took it to the local garage as a last resort. They put it on their commercial grade charger overnight and it was back to full in the morning.

Then again, left the caravan under fabric cover for about 18 months.....same battery. The hope was that sufficient light would filter through the fabric to the solar panels to keep a minimal charge in the battery. Alas, when we removed the cover and tried the battery, again it appeared dead. Same story as above when I connected it to my home charger. Once more off to the local garage....different garage than last time. I explained the situation to him and he was sceptical, but to his credit agreed to give it a go. Once again, following morning and it is fully functional.

The last time was approximately 6 weeks ago and all is still going OK.

Moral of the story....indeed it may be stuffed....but what is there to lose by trying it on a commercial charger.

Cheers
Phil

What is there to lose? Time, lots of time.


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Originally Posted by Phil_H

Simple solution then.....buy an new one......time saved....wallet lighter....

Cheers
Phil

and give your old one to Phil....he will buggerise around with it in spare time and then will have a spare battery LMFAO....

So for future reference here's the update.
Took the battery in to the local Auto electric business. They did their thing, charged it to about 70 % they said. Cost me zip.
Brought it home, drained some power like they advised, charged it up to full on me mates new fangled computerized charger. Checked it yesterday (4 days after charging to full) and still full charge.
So there ya go

But what did the auto leccy actually do mate? Did you ask him?

I don`t use deep house batteries, Just put a marine starting one in to my caravan, works good. well I hope so.

Originally Posted by hamsav

Why are they called deep cycle ? I thought you could leave them for ever and it would still be charged and or you could leave them flat for ages . Those motobat jobbies are the ducks nuts for bikes ect but I dont think they make them big enough for cars . :-)

Deep cycle are built with thick lead plates to handle deeper discharges / charges, but still behave like lead-acid batteries, ie, self discharge slowly over a period of a few months, and the plates sulphate up when the voltage falls below a certain level. They perform best with a loads of a few amps over a longer period of time. Not intended for starting you car.

As opposed to:

Engine Starting batteries: Lots of thin lead plates, lots of surface area in contact with the acid solution inside, so can deliver high currents for short bursts, not intended to be discharged for more than a few seconds at a time. Great for cranking motors over. Not intended to be heavily discharged. More susceptible to distorting / falling apart inside from heat stress, charging/discharging cycles.
As an aside this also covers the difference between cheap shitty batteries and expensive ones - 'Cold cranking amps' reflect how much lead is in contact with the acid. Makes those lead plates super thin and you have a low cost battery that can deliver the numbers when new, but will distort and fall apart inside sooner.
See at a '4x4' battery thats 3x the price but doesnt deliver3x the amps? Thats because money invested in robust internal construction and thicker plates doesnt mean more CCAs, but it should mean longer life.

Originally Posted by svt40

Deep cycle are built with thick lead plates to handle deeper discharges / charges, but still behave like lead-acid batteries, ie, self discharge slowly over a period of a few months, and the plates sulphate up when the voltage falls below a certain level. They perform best with a loads of a few amps over a longer period of time. Not intended for starting you car.

As opposed to:

Engine Starting batteries: Lots of thin lead plates, lots of surface area in contact with the acid solution inside, so can deliver high currents for short bursts, not intended to be discharged for more than a few seconds at a time. Great for cranking motors over. Not intended to be heavily discharged. More susceptible to distorting / falling apart inside from heat stress, charging/discharging cycles.
As an aside this also covers the difference between cheap shitty batteries and expensive ones - 'Cold cranking amps' reflect how much lead is in contact with the acid. Makes those lead plates super thin and you have a low cost battery that can deliver the numbers when new, but will distort and fall apart inside sooner.
See at a '4x4' battery thats 3x the price but doesnt deliver3x the amps? Thats because money invested in robust internal construction and thicker plates doesnt mean more CCAs, but it should mean longer life.

Great explaination