TOPCON BT-32Q AND 23Q (THE SAME BATTERY PACK IS USED IN BT-23Q, 31Q AND 32Q) NEW BATTERY PACK INSERT UPGRADED TO A 7.2V2.7AH NI-MH, REMOVE THE OLD BATTERY PACK INSERT, REPLACE WITH NEW BY MAKING 2 EASY WIRE CONNECTIONS. PRE-WIRED AND INSULATED. ALL OTHER SURVEY BATTERIES ARE AVAILABLE. WILL CHARGE WITH YOUR CURRENT CHARGER,