I have a 90 V motor I'm testing on a bike. I ran it with two Bosch corldess 18 V batteries in series. With 18 volts it ran about 10 miles per hour. With 36 volts (both batteries together) about 20 miles per hour. I have two 14 volt batteries from another power tool set and I'd like to connect them together in series to bring it up to 64 volts. Can I do that? I want to test it first to see if it's about what I want for the speed before I buy my permanent battery.
Can I connect 18 volt and 14.4 volt batteries together in series?