Parallel/Series switch between 12V and 36V?

[swbluto]

I have 3 12-volt batteries that I want to put into parallel for my 12-volt tools and then I want to put them into series for use in my 36-volt tools. While I could do this by unplugging the connectors and plugging them in by the right way, I was hoping for something a bit faster for the switch from parallel to series and vice versa, ideally through something like a switch. Does anyone have a switching diagram or instructions for such a switch if it's possible?

Right now, the only thing I can think of is creating two different circuit boards with the appropriate connections so that one is the "series board" and the other is the "parallel board", and then the batteries leads would plug into one board for 12Volt output and then plugged into the other board for 36 volt output (Or, some kind of equivalent wiring could be used instead of circuit boards). But, a switch would be whole lot faster and more convenient if possible. Thanks!

 

[stanz]

The only way I could think of doing it with one switch is to use three dpdt relays.

You could also use three dpdt switches to eliminate the powered relays.

You might want to add a disconnect before the load for safety.

 

[dogman dan]

Series them, for the 36v tools. Then buy some 3s lipo for the 12v ones. Worth the expense, even if you don't have lipo chargers yet. You wont regret it. Later of course, you'll end up buying some 5s lipo for a 10s pack for the 36v tools.