NoI bought the harbor freight 45watt, 12vdc charge controller solar kit.
Can I charge my two 24vdc batteries with this kit?
YesDo I need to buy a 24vdc charge controller?
Maybe.....Can I build a DIY step-up converter (12vdc to 24vdc)?
If you connect your two 12V batteries in parallel, + to+ and - to -. you have created a 12V battery with double the Ah capacity. Your panel will be charge that just fine, but it will take twice as long.Wouldn't that just double the amps and voltage would still be 24vdc?