72 volt club car

yes you do need some kind of controller just stepping battery volts will kill the batterie's and be worse on amps then a controler.
plus keeping the batteries balenced is all most impossible as the first batterie in the line will be as flat as a wet fart and the last one will be half full dont do it.
A new speed controler only costs a few hundred (200 for a 200amp 72v atrax)(get a second hand one).I have tried stepping once only for testing. using 3 heavy duity relays.it did the job but like i said it kills batteries.

But i have made a good cheap speed controler myself
Basicaly get a small speed controller 12v 5amp mapplins job. change the timing caps to slow it down to the max frequency of a 1000amp scr and use the speed controler with a 10k resister to pulse the scr. the whole speed controler cost me £30 to build. i got the scr of a mate who repaires stacker truks (free).it worked fine but u need a good heatsink . does any one else know a good way of making a cheep speed controler (brushed)