Battery charging

the_worrier · 23 Oct 2023 at 04:35

So, having analysed my car with a Carly OBD2 scanner thing it seems my car battery might need charging. Poking around on the web suggests the battery may be ‘AGM’ as the car has stop/start.

I have a CTEK MXS 7.0 charger as I use it to charge my caravan leisure battery.

Silly question but can i connect the charger to the car battery with the car still connected?

Rroff · 23 Oct 2023 at 04:55

You can charge it still connected - advice is usually to charge it by connecting the positive to the battery terminal and negative to bare metal near the battery.

BUDFORCE · 23 Oct 2023 at 06:52

Yes it'll be fine.

sovietspybob · 23 Oct 2023 at 09:19

My CTEK charger has an AGM mode, see if yours does too.

I think you do need to be more careful charging an AGM as they're more sensitive than old lead acid batteries so a normal charger might damage it but im not really sure as i've never had an AGM battery myself.

Dangerous Dave · 23 Oct 2023 at 09:33

The older CTEK chargers don't show a AGM mode, the cold temperature mode charges with the higher voltage needed for AGM batteries so use that one if it doesn't show AGM.

Finglonga · 23 Oct 2023 at 15:20

Why does it need charging would be my first thing to find out. Unless you are leaving the car standing for long periods, is the Alternator faulty, a parasitic draw or the battery is old? Never had to charge a battery unless there is something wrong and fix it before the cold weather gets here as it could leave you stranded.