Leisure batteries question.

[MarshPhantom]

Went away last week to find our batteries were dead when we got there despite having charged them recently.

Having tested them the batts are totally flat but the Numax charger thinks they are full. Is this simply a new charger we need or could it be something else.

Thanks for looking.

[Fishtigua]

You need to get the batts load tested. They can read 12v to the charger but as soon as you put a load on them, they fizzle out. Be prepared for new ones.

[MarshPhantom]

Cheers, hopefully not the batts as they're only a couple of years old. I'm currently charging the batteries with a different charger.

Fingers crossed.

[Hybrids]

When did you last use them, have you kept them on a trickle charger since you last used them ?

What voltage are they showing
Sound to be heavily sulphated if the charger thinks they are charged.

[MarshPhantom]

Charged them 3 weeks ago and used the van last weekend. Don't have a trickle charger.

My meter showed 0V on both batteries this morning.

[Hybrids]

0v on a multimeter or battery display in the caravan ?

Typically an unconnected battery will self discharge around 0.5v per month, though there are variables.
I would be inclined to say something has pulled the batteries down, most battery chargers despite claiming sulphation recovery can't recover deep discharged batteries.

Purely as an observation and in no way a recommendation; what I have done in the past is get a decent sized fully charged battery, connect with jump leads and leave connected for an hour or so. Still with the jump leads connected, connect the battery charger to the jumper battery and leave it to charge, with periodic checks. As I say, use this information if you feel it is suitable to your situation, I take no responsibility for any outcome.

You Numax charger, I guess is less than a 10 amp, so expect a long wait

[MarshPhantom]

Thanks for that, the multimeter was showing 0V.