Tired of replacing lead acid batteries?  This lithium ion battery has more than double the runtime, fits the stock battery tray and is protected from overcharge/undercharge so it will last.  Adapter plugs directly into 3-pin factory razor harness.  Charging times are half of stock razor (4hrs).
 
•FITS RAZOR MX350 and others with side-by-side 12v7ah lead acid.
•25.2V LITHIUM ION BATTERY
•40A CONTINUOUS DISCHARGE
•60A MAX DISCHARGE (1 SECOND)
•1,440+ MAX WATTS
•L X W X H ~ 6 X 3.1 X 4.8"
•3A CHARGER INCLUDED
•5A MAX CHARGE CAMPATIBILITY
•EVE 21700 CELLS (15mΩ@1kHz)
•ANT BLUETOOTH BMS
•XT90/10AWG DISCHARGE PORT W/MATING PIGTAIL
•XT60/14AWG CHARGE PORT
•COMPLETE BATTERY PROTECTION
•FREE SHIPPING (LOWER 48 STATES ONLY) NO SHIPPING TO HAWAII
•ORDERS TYPICALLY DELIVER IN 5 DAYS FROM TIME OF PAYMENT
•IMPORTED
HOTPAXXLLC Battery Operating Manual