I needed the big Trojan T105 batteries for the solar battery bank, so I needed to make a replacement.
Most of the yard buggy use is to move something from one part of the yard to the other, or to collect wood, so the buggy only needs enough battery to make a couple of trips around the yard, instead of the giant heavy lead batteries which pack 220AH, I decided to make up some prius packs equivalent to the 48V lead pack, but with only 15-20AH. They charge faster, and are much lighter.
Started by reconditioning the old gen one (288V) modules. These modules came from several sources, including two packs that were in tough shape, so it was not surprising to find very poor performance from more than half of the modules. The grid charger is a nice tool for this, and to prevent the distortion of the modules durng the gassing stage of the charge, I made some end plates with 3/4" plywood, and some long 1/4-20 threaded rods to compress the modules.
I made a special paralleling cable where I can plug the 48V modules into a common buss, and then plug both ends of the buss cables into the 50A Anderson connectors already on the buggy.
WOW! the NIMH internal resistance is much lower than the lead acid, so the voltage droop under full load is almost non existent, compared to the lead batteries. Can scrub out at will on any surface, so now the issue will be to get enough weight over the rear wheels, so I can pull my trailers. Will rig up a solar quick charger for the packs, but until then, my grid charger will do the job but more slowly.