Charging two batteries with one charger

[scootergrisen]

Here is a charger with 2 battery connectors.
This charger seem to be made for 2 batteries from the factory while the other charger i showed earlier had a Y-connectors to go from 1 to 2 battery connectors.

 

[amberwolf]

I would guess this just has the y-connector built into the cable, and that it isn't actually two separate charging circuits with separate wires. The cable from the Y-point to the charger is no thicker than the two arms of the Y, implying that the wire is the same and that it only has two wires in either arm *and* only two in the main cable.

So...all the caveats about charging paralleled batteries would still apply--they'd both have to be at the same voltage to start with, since you'd be paralleling them (via the charger wires), and be in the same condition, etc. If not, then problems may happen (potentially catastrophic, unlikely but possible).

 

[99t4]

I have two identical batteries wired in parallel, common-port BMS (charge/discharge ports on the same wire from BMS) on each. Charge both batteries at the same time from one charger thru a Y cable. Has not been a problem for years.