Golf cart battery chargers are typically either 36 or 48 volt, and they are meant to charge three or four 12 volt deep cycle batteries that are connected in series. But they usually have ring terminals on the charging leads rather than the large alligator type clamps used on most battery chargers. Something like this would also work:
http://www.sears.com/schumacher-electric-se4020-10-40-200-wheel-charger/p-SPM6299660701You could charge one battery at a time or you could charge several that are connected in parallel. Of course, fully charging one battery at 40 amps is going to take less time than charging three or four that are hooked together in parallel.
Precautions should be taken when charging lead acid batteries. Hydrogen gas is produced while charging, and connecting or disconnecting under power can create a tiny spark which will cause a battery to explode violently. I once was asked to check out a golf cart that wouldn't run. I immediately noticed a lot of corrosion around the battery terminals and felt that would be a good place to start. I asked if the golf cart had been on charge and was assured that it had not been plugged in for several hours. It turns out this information was wrong. I commenced to remove one of the leads and as soon as I broke the connection, one of the deep cycle batteries exploded. It sounded like an M-80 going off and the entire top of the battery case blew off. I got sprayed with battery acid and a piece of shattered plastic cut my neck. Thankfully, I had safety glasses on and was close to a restroom where I could quickly rinse the acid off my face. I later learned that this golf cart had been on charge until shortly before I was asked to fix it.
