I use a Cycle Satiator variable voltage charger. I bought the 72 volt model. You can program the charging rate and the charging voltage or choose form their pre-programmed charging options. It charges the battery intelligently to maximize battery life. I discard a lot of the BMS units on my packs so I need a good charger to help keep my batteries healthy. This thing is versatile as fuck and although its a little expensive, think of what youll end up spending on 3 or 4 different chargers (that youll probably have to replace ). Its actually a very good value if you think about it. And it can charge batteries up FAST if you need it too. It says it charges from 36-103 volts but mine goes as low as 8 volts and as high as 96 volts. Ive never tird to charge at a higher voltage, but I bet it would do it. Easy to use and so far its been rock solid. I use it on my scooters, the supplemental and custom battery packs I create and my car batteries and even my lowriders' hydraulic battery systems. The thing does it all.
I just spliced generic connectors on the end of its wires and have a little collection of different charging fittings I can plug in when I need them. Works for me and I love the thing. It does it all.
https://www.amazon.com/Satiator-Program ... B01LWT3UH0