Our onboard charger seems to be killing our leisure batteries.
We have 91 Coachman and are having problems with the charging system. Basically thinking it was a dead battery I connected a spare that had been fully charged away from the van and all seemed OK. Today, 2 days later I have been in the van and the battery is dead, only reads 6.5volts.
The reading on the charger terminals at the battery is 1.2volts which is obviously low but all 12volt lights work fine as does water pump and reads 11.9 volts on the ceiling light and awning light.
Any ideas why this would happen, is the charger faulty; why 12v at lights and only 1.2v to battery?
Is that measured with the battery removed? Some need the battery in place to take a reading because the chargers sensor will detect no battery and not put power to that circuit.
Assuming its a smart one.
Or the charger is comprised of several in one unit with each line out being a sepaarte circuit?
Hi connect battery with mains turned off to caravan, then take a volt reading at battery terminals then switch on a couple of lights reading should fall, get someone to switch on the mains as you watch volt reading it should rise if charger is working. If its not working check fuses including any line fuses.
Firstly, the charger/PSU only has one output and I doubt it would be a smart charger as it is very old.
As albee says I have reconnected the battery but neither are strong enough to switch lights on. The reading is 6.4 volts with mains off and 7.6 with mains on, so the 1.2 volts on the charger terminals seems correct.
I have also tried both batteries on an external charger and the charger reading alternates between fully charged and dead every second, so it seems to me that both batteries have somehow been killed by the van charger.
All lights etc still work and I get a reading of 11.9 on the awning light.
seems like something is shorting it.you should get about 12.5 volt at battery and around 13.5 charging.Charge voltage has to be more than battery voltage or it wont charge.One trick i use on mobility stuff which are similar batts is leave a lamp such as an old headlamp from a car connected till it goes flat ie lamp not lit.Then charge overnight,if batt wont accept a charge because its too low then simply connect charger and switch on,then get a good battery and connect that to the charging battery for about 20 to 30 seconds,this will start the battery charging.We call it piggy backing.I have quite often got batteries that failed at say 20% back up to 90% or more.I would get the van electrics checked
I have just been out and checked all connections again, including the rear of the control/switch panel and I now get 12.6 on the charger terminals (battery end and battery disconnected).
Problem now is....... was the fault causing the discharge of the batteries or are they just knackered? And will the van charger be capable of recovering the bats?
Just reconnected and reading at the battery goes from 6.5v to 8.2v (ish) when turning on the charger.
Hi, firstly take both batteries to a local garage or auto electrician get them tested with a discharge tester bet they have shorted cells, just how old are these batteries. have they been recharged at least every 8 weeks. have they been stored off a concrete floor either of which can kill a battery.
it sounds like your charger isnt working and isnt charging your batteries..
its easy to find out.. i think its been said already..
with the charger running put a volt meter directly on the battery terminals.. if its working it will read around 13.5 volts..
if the charger isnt working you battery will simply run down and go flat..
running a battery down wont kill it.. with a working charger it will charge back up again..
a fully charged battery will read around 12.5 volts.. this is without any charger running.. if the charger is running it would read around 13.5 volts..
to me it sounds like your charger isnt working.. or at least isnt charging you battery..