Switching Battery Voltages

[stvgeorge]

Hi all,

I've been lurking for a while - this is my first posting, so please forgive any blunders.

I have a 36v Elec-trac ride on mower and a 12v 'Hugh' style windmill (8') presently charging some low capacity 12v batteries.

I'd like to charge the mower from the mill.

Is it sensible to install switches between the 6, 6v bateries on the tractor to enable them to charge from 12v (i.e 3 parallel pairs) and then switch them back to 36v (serial) for use.

I appreciate this would require some heavy duty switches to handle the drive current and have no idea where these would come from.

Or perhaps there's a better way?

Any comment appreciated - they can only help.

Steve

[Flux]

Yes you could do it, but it would be messy. I think a boost converter from your 12v battery would be easier, presumably you are not in a hurry and a small converter would be adequate.

I believe TomW and Ibedonc have done something on these lines and may have a kit.

Flux

[scottsAI]

I hate switches, they fail.

Couple ideas.

Use a 12v powered inverter to 120vac. Use to power a charger for the 36v.

Efficiency 60-70% (swag of a guess). This should be simple to do.

Second is the already mentioned boost converter.

Efficiency 80-90%.  If your handy a 200 watt converter should not be difficult. Charge controlling is not difficult. If you have a broken inverter all the parts you need are there. Need a different control circuit, etc. Make any size you need.

Have fun.

[John II]

Also if you used switches, It would be almost impossible to keep the batteries uniformly charged. This could lead to the demise of your batteries.

John II

[davharv]

Hi there ET'er don't see too many of them here. try http://www.crystel.com for solar ET by Chris Z.

Dave