On Fri, 21 Jun 2019 13:37:01 +0100, Bill Wright
wrote:

On 21/06/2019 09:23, T i m wrote:

I find it 'safer / better / easier' to charge each battery (in series)
individually, especially as they age or aren't well matched in the
first place (especially if the charger capacity is quite good).

If you do two at once presumably you disconnect them...

No need, as long as the outputs of the chargers are 'floating' (and
they generally are).

This means you can use a single 3 pole connector to do them both at
the same time.

I bought a new pair of Lucas AGM GEL for what was Dads TGA mobility
scooter when the previous batteries got destroyed by not being charged
at all for a long time.

After charging them first individually (on the Optimate4) I put them
on the scooter and plugged in it's 24 volt charger but that never
seemed to turn off (= go into maintenance mode).

So, had I left it on it would have destroyed the new batteries. ;-(

I've since tested the idea of charging them independently whilst still
plugged into the scooter loom using two Optimate2's and they work fine
(and both shut off when they should etc).

There could be something wrong with the (new) 24V charger of course
but it did actually work as designed on a different pair of 12V
batteries (suggesting to me that it's not 'smart' enough for my
liking).

And these batteries aren't cheap eh. ;-(

Cheers, T i m