Intelligent Battery Chargers

[Wheelz]

I still have, and use a couple of old school battery chargers, but having just started to use one of these microprocessor controlled types, I realise how much faster they can be.
I am using a Foxsur 12V/8A charger, which has a temperature sensor, and modes for standard and AGM batteries, and also a Pulse Repair mode for old batteries. Pretty good for under £20.

You can also leave it connected without supervision as it turns off when fully charged, although ideally I would not really want to leave any batteries on charge overnight. I dont know if it would work as a maintainer though, in other words if left connected would it top up as the battery voltage ran down?

[marshman]

Some do and some don't. Some will over charge if left on for extended periods. Best connect it up and monitor what it does over a long period using a DVM to check the voltage.

I would hang on to your old school chargers - well at least one of them - as not all of the "intelligent" ones will start to charge a totally discharged battery - Some chargers get confused and think that they are connected to a 6 V battery as the terminal voltage is too low, others flag an error/fail when the battery initially refuses to take enough or significant charge current. In those cases 24 hours on an old trickle charger raises the terminal voltage and drops the internal resistance enough for the "intelligent" charger to "be happy" and take over.

[StagJonno]

I've experienced similar with over-discharged batteries with a new-fangled charger. Wondering if putting a power pack emergency start unit on for a few minutes would put enough in to get the voltage up to a level which would allow the charger to function? Might find out one day .

[mole42]

I have two of those intelligent chargers, ones quite old and the other I got more recently. Both really can't cope with a discharged battery so I keep a dumb charger for those occasions when I need to bring a battery up from dead. Before I replaced the battery on my car I used to leave an intelligent charger on all the time it was in the garage just to make sure I could start it when I needed to! With a new battery I haven't had that problem....

[Wheelz]

So the ones that wouldn't respond to a discharged battery, did they have a Pulse Repair Mode that still didnt work?

[mole42]

One of them does but it needs to see a voltage (don't remember how many volts) before it'll start the repair mode. That is the older of the two, but it's an Opti-Mate so it should be a good one!

[MandM]

I use a Oxford optimizer , all been fine

[wilf]

I leave both the Stag and the standby generator batteries connected to "battery charger/maintainers" - Ctek in my case. Kept the batteries in other infrequently-used cars going for virtually ever! Lead acid batteries hate just "standing" for long periods - they effectively "eat themselves", the proper term being sulphation.

[mole42]

My Stag never stands for long periods!

[paul jorgensen]

I have CTEC smart battery chargers permanently on old cars and have no issues with batteries