If I was wanting to do a 12V solar charger for 72V I would probably build the one dcb has listed. It is a simple circuit so that means there are fewer things that can go wrong.
Simpler is always better if it does the same thing as the more complicated circuit. But for my setup I will probably stick with the one I posted since it does continuous balancing of the batteries and swapping out the 555 in the circuit for an arduino could give me a lot more capabilities like measuring volts/amps and having a display show total KW used or something. I can never leave well enough alone it seems like
