On 12/13/2016 6:14 PM, jim wrote:

old tractor, 2 x 12v biggish batteries linked in parallel provide
the power to start.

Only used for fetching haylage once a week so batteries often
don't start it the next time....

Is it OK to just charge the pair of batteries by clipping on a
battery charger, without disconnecting the interconnecting
wiring?

Or is it necessary or advisable (and why please) to electrically
isolate each and charge one at a time?

For longer term would a solar trickle charger be worthwhile?

TIA

With this arrangement, isn't there a danger that if one battery
deteriorates (e.g. a cell shorting out) it will knacker the good one?

As others have said, since the generator charges them like this there's
no reason not to do the same with an external charger.

Was this the original arrangement or is it a later bodge? I think if it
was mine I would fit a "quick detach" connector to each of the positives
so that I could monitor the batteries separately. And perhaps just start
on one?

I have these on a couple of my "yard" vehicles because they seem to have
some discharge current when left connected.

http://www.ebay.co.uk/itm/Battery-Cl...AOSwo3pWenR l