Hi,
I have two 12v battery units I use alternately to power the electric fencing for horses. It usually runs the perimeter of an acre to acre and a half and I alternate them, usually recharging the spare battery ready to be plugged up when the other starts to run out. Neither of them are recharging properly, the low battery light comes on the energiser as soon as they are hooked up, even after a 'supposed' full charge is there any way of reviving the batteries or are they now duds??
Many thanks.
Every time you charge and discharge a lead acid battery a fine " glaze " of sulphate of lead forms on the battery plates ( think it may be the positive plates )
over sixty or so cycles this sulphate coating builds up causes resistance to charging.
till you get the situation you now have . Many many folk will throw the battery away , garages , mechanic's electricians & electronic engineers will tell you to buy a new battery .
How ever good news there is a new type of battery trickle charger that over comes this long term sulphation it uses short high frequency bursts of a voltage that is fractionally higher than the discharged battery and over 24 hours of so can actually bring up a supposedly dead battery till it is infact more effective 7 efficient than a brand new battery
They are some times known as gold buggy battery chargers .. But the best ones I know of are called de sulphation battery chargers.
Mine cost me £24 ish for one able to revitalize a 100 Ah heavy duty cycle caravan battery . If you go this troute make sure that the one you choose covers the sized of your batteries amphere hour capacity getting too small a one does not usually give as good results as the correct sized one.
my caravan ledger battery became discharged to 1.4 volts .
so you can imagine what has been said to me when I was seeking the de sulphation type charger locally .
After 8 days it has now recovered to 2.5 volts when disconnected for 5 minutes .. Ok for me this will be a long slow job of say a month or so but it will save me something like £90 if it works out well .
Look them up on eBay and please do read up on this type of charger on Wikki etc . ..the more folk that know of them the better the outcomes will be .
Please note .....that this type of charger is not one of the usual electronic sampling battery chargers found in the likes of Halfords for £60 or so