Tired of replacing lead acid batteries?  This lithium ion battery has nearly double the runtime, fits the stock battery tray and is protected from overcharge/undercharge so it will last.  Optional adapter available for direct plug into your factory razor harness.  Charging times are half of stock razor (4hrs).
 
•36V LITHIUM ION BATTERY
•40A CONTINUOUS DISCHARGE
•100A MAX DISCHARGE (1 SECOND)
•3,600+ MAX WATTS
•L X W X H ~ 8.5 X 3.6 X 5.5"
•5A CHARGER INCLUDED
•10A MAX CHARGE CAMPATIBILITY
•LISHEN LR2170LA CELLS (9mΩ@1kHz)
•XT90/10AWG DISCHARGE PORT W/MATING PIGTAIL
•XT60/14AWG CHARGE PORT
•COMPLETE BATTERY PROTECTION
•FITS RAZOR MX500/650, SX650, RSF650.  REQUIRES STRAIGHTENING OF ONE TRAY END.
•FREE SHIPPING (LOWER 48 STATES ONLY) NO SHIPPING TO HAWAII
•ORDERS TYPICALLY DELIVER IN 5 DAYS FROM TIME OF PAYMENT
•IMPORTED