Battery charging charger amperage

[yetihair]

Hello,
Will it take 12 hours to charge a 72ah with a 6a charger or doesn't it work like that for charging?

[California Dreamin]

Sort of...in theory at least. However, the reality is that your battery should never be allowed to go fully flat as this kills them very quickly.
Also, modern charges don't just blindly give their full rating, most start with a 'bulk' charge delivery (initially the full rating of the charger) but then will quickly tail off to a fraction of their rating..1.5 - 2 amps and fall even lower for the last few hours, perhaps less than 1 amp.

Just buy a 'smart' stepped charger and leave it to the electronics to condition the battery and give the optimum charge regime. These smart charges can be left connected for several days without fear of overcharging, as they automatically switch to a 'floating charge' state when the battery is fully charged.

Martin

[yetihair]

I thought that was probably the case.
I wouldn't normally let the battery go flat, but the vans been in the garage for a week and a bit and they haven't isolated the battery with the isolation switch. I guess I have a little drain somewhere but finding that has never been a priority yet.
So the battery is flat dead and on charge when I'm in the house and not sleeping (the wife isn't keen to leave it on charge, fair enough I think). I'm not best pleased it's ended up completely dead as it's a brand new battery. I hope I haven't done it any damage.

[AdrianC]

I wouldn't normally let the battery go flat, but the vans been in the garage for a week and a bit and they haven't isolated the battery with the isolation switch. I guess I have a little drain somewhere but finding that has never been a priority yet.

If it's flattened your battery in a week, that's not a "little drain". That's something you want to be investigating.

[California Dreamin]

I thought that was probably the case.
I wouldn't normally let the battery go flat, but the vans been in the garage for a week and a bit and they haven't isolated the battery with the isolation switch. I guess I have a little drain somewhere but finding that has never been a priority yet.
So the battery is flat dead and on charge when I'm in the house and not sleeping (the wife isn't keen to leave it on charge, fair enough I think). I'm not best pleased it's ended up completely dead as it's a brand new battery. I hope I haven't done it any damage.

As Adrian says ^^^^ that sort of drain needs investigating.

As for worries over charging in the house...if all you have is a 6 amp charger, then the activity created by this relatively low output unit charging a 72ah battery, won't be making the cells that gaseous. Obviously, there are precautions ie: stand on a couple of old newspapers and in a fairly well ventilated area.....turn the charger on/off at the wall socket (turn off the charger before disconnecting).

Martin

[yetihair]

I think I know what the drain is. Whilst lying in the r&r bed the first and only time I noticed a faint glow from one of the led modded courtesy lights. I think there might be a shortage in the switch. Thanks for the input guys