I'm looking at two options. Both could have a charging BMS that just protects the high end or a 4x as expensive BMS that will cutoff the power when it hits low voltage. One could also use the charging BMS along with some other means of sounding alarms if there is low cell voltages as there are many cheap cell log devices that track voltage for remote control lipos.
2 "48v" Chevy Volt modules with a total of 95AH which sits at about 45 volts max of 50v. This pack would spare any high voltage issues and the discharge graph lines up well with my mowers approximately 41volt deck cutoff. I could with major surgery maybe get another module in but that involved cutting off the back of the mower and moving it back and raising the seat a bit or cutting some stuff off the volt battery in addition to moving the seat up.
The nissan leaf kits comes in with 60AH or 120AH and fits with no issue if you buy the kit. The metal box encloses the charger and other items which make it a little tall/wide and since the zeon is a metal box I was thinking i'd just want to put a plastic box around it to keep everything out. It does have a higher voltage with 2 extra groups in series with a stated 53.2V average, 58.8V max and a cutoff at 42v. The charger can put the lead acids that high although they won't stay that way for long at all and I'm not sure how fast the leaf batteries would drop down to the 53v. I also may need a low voltage alarm/cutoff unless I can get a kit with two less in series to match the chevy volt pack or failing that get them to tune the BMS/Charger to 12S and keep the extras for spares.
So I'd have the following + BMS on the end in a box
discharge curve on a leaf cell. If i'm reading it right the full 14S kit would be almost 48 volt when the batteries is 90% empty. Too high for my comfort level I think I'll have to ask about just getting 12 in a series.