leisure battery testing

[nyx2k]

i bought an 85amp hr leisure battery about 2yrs ago and fully charged it. however i never got around to using it and now have rediscovered it at the back of the garage.
Ive put it on charge but how do i test if its no longer any good.

 

[VicS]

Top it up if necessary, charge it until its been at 14.4 volts at least for a couple of hours. Then monitor the volts while it stands over a period of several weeks. If it stays s at 12.6 or more for a decent period there is a chance that its OK.

Also check it with a hydrometer if you have one.

If it is sulphated it might benefit from a short spell at up to 16V or from charging with a charger with a pulse desulphating facility

If it has stood neglected for two years though it is most likely stuffed!

 

[nyx2k]

im using a halford battery charger to recharge at 8amps.
i also have something called an oxford oxymiser that charges at very low amperage but is suppose to revive battery's i think.
i will leave the battery charging until bed time and restart in the morning.
if its no good at all will it lose its charge quickly within 24hrs or is it more gradual. i have a multimeter so can check regularly

 

[jerryat]

If it is going to recharge successfully, you will be better using low amps (say 1-2amps) over a long period, rather than 8 amps in relatively short bursts. If your 'Halfords' charger has a 'low-charge' setting, use that. Using a low amp charge rate, I would expect it to take at least 48 hours to reach a fully charged state - if it is indeed possible after such a long uncharged period.

 

[nyx2k]

the charger has a switch that says 12v car or motorbike. which i presume is high amps and lower amps and a switch for lead acid and gel batteries.

 

[bazobeleza]

motorbike is likely to be 6v

 

[nyx2k]

it says not suitable for 6v so presumed a lower ampage.

 

[scooberal]

i would be inclined to charge it over night , then take it to a local tyre /exhaust place and get them to drop test it ,
this test is done by putting a load on the battery and at the same time mesuring its out put , checking( cca,s) coldcranking amps
and also volts at the same time

if you ask them nicely i suspect they wont even charge you "excuse the pun"

 

[William_H]

To test the battery yourself you need to recharge it fully then run a load on it for a number of hours. A car headlight bulb or Quartz down light of 50 watts will do nicely. You should be able to get about half the rated AH ie 9 hours at about 4.5 amps with the battery holding up above 11.5 volts.
Next you should try an engine start with the battery preferably a day or 2 after being charged. Boat or car but be carefull of sparks when connecting it up.

If the battery will pass these tests then it is OK for service in a typical boat.You may be willing to accept even less than 50% capacity on running services all depending on what your boating style is and if you feel like dumping the battery and buying a new one. olewill

 

[cliff]

OK for an engine start battery but not really suitable for a leisure type battery and certainly not recommended for deep cycle batteries.

Charge it up as far as possible, leave to sit for a couple of days then SLOW discharge (50w bulb) and monitor the voltage drop over several hours (12) - depending on the result you will have a good idea of the battery's capacity. Remember leisure batteries are intended to deliver low current for long periods not high current for short periods.

---------------------

Artificial Intelligence is no match for Natural Stupidity

 

[oldharry]

The cheap 'Deep Cycle leisure batteries' sold in the Uk around £35 -£40 can be damaged or detsroyed if used for starting a car engine. They are not designed to give the heavy amperage needed by a starter motor, the plates overheat and may buckle giving an internal short circuit.

'Deep Cycle Traction Batteries' - the sort of thing fitted to wheelchairs - are a much better option as they can tolerate starter motor current levels intermittently. But of course they are not so cheap!

Cliff's discharge test is the best for Leisure |batteries