Wiring 3 lead-acids simultaneously in series and parallel

[TheAmmoniacal]

I'm very inexperienced with electronics, but I've bought this kit to convert my bicycle into electric. As for now I'm thinking of using three lead-acid batteries that I have already. Two of them are "gel" type and one is a "maintenance-free" type. I already have a quite expensive and beefy 12V lead-acid battery charger, and my motor runs off 36V. So I attempted to wire the batteries both in series and parallel, but that resulted in smoke.

I want to run them in series for the motor and simultaneously have a parallel connection where I'd hook up my charger, is this possible? Would two beefy diodes work?

Thanks.

[IanB]

I want to run them in series for the motor and simultaneously have a parallel connection where I'd hook up my charger, is this possible?

Only with a switch, or with two different wiring harnesses not connected to the batteries at the same time.

[mikerj]

I want to run them in series for the motor and simultaneously have a parallel connection where I'd hook up my charger, is this possible? Would two beefy diodes work?

You can't simultaneously have a series and a parallel connection at the same time without smoke. No amount of diodes will help you.

It's also a bad idea to connect different types of batteries in series, especially if the capacity varies between the batteries.

You either need a 36v charger or three (isolated) 12v chargers or you will have to physically re-arrange the connections for charging, either manually or via high current switches/relays.