We use a Dual PRO RS3 and it works great. We used to use a raw car battery charge with 9 batteries in parallel but it only charged the battery to 12.6 volts and slowly.
We put a boat battery on are cart with a
Turnigy accucell 6 wired up for internal charging, Last minute queue charging and secret overnight charging. What's nice about it is that it has a display to show the voltage and it runs of a 12v supply (it will charge above 12v). It's also dirt cheap