NOTE--The factory razor controller will not allow a 48volt charge threw it so you have to run charge port wires directly to batteries or to main power wires going into controller unless you have my controller kit. This is a overvolt kit charger that is a must for those doing a 48volt conversion on your mx500,mx650 or eco smart for sealed lead acid or AGM batteries not lipo or lithium. Nobody sells a charger in 48volt for your mx,nobody..Thats why we do but then again nobody sells overvolt kits for your bike either so make sure you save us to your favorite sellers list being we ad new items weekly.. This charger has a built in fan,pretested with the output on the back,it charges at a 2.5 amp rate and does cc,cv and floating which is the only way to charge SLA batteries and get the longest life and runtime out of them.. This charger works in all countries too.. 110v-240v Safe,dependable charger that works properly..