Viper 3706V Remote Start Compatible Battery 3.7V 600mAh

Viper 3706V / 4706V Series — 3.7V Li-Polymer Replacement Battery (JFC503040)

This 3.7V 600mAh lithium-polymer cell replaces the original battery in Viper remote start and keyless entry transmitters, including the 3706V, 3806V, 4606V, and 4706V models. It matches the OEM part number JFC503040 and fits the same footprint at 41.16 x 29.70 x 5.00mm. When the original cell degrades, range drops and the remote stops triggering the control module consistently — this cell restores that connection.

• 3706V / 3806V / 4606V / 4706V transmitter compatibility: These remotes share the same battery bay dimensions, connector orientation, and 3.7V supply rail. The JFC503040 cell fits all of them without modification — the transmitter PCB draws directly from the cell with no intermediate voltage regulation.
• Bench tested on actual hardware: We cycled this cell through repeated remote start and lock/unlock command sequences on a 3706V transmitter. The cell held voltage above 3.5V through sustained button presses and the RF transmission bursts without dropping out.
• Post-swap re-sync requirement: After replacing the remote battery, re-sync the remote to the Viper control module. Swapping the cell interrupts power to the transmitter's memory, and most Viper systems require a programming sequence — typically entering valet mode and pressing the transmitter button within a set window — before the remote will activate the system again.

Remote start not activating after battery swap

Viper remote start systems use a rolling code protocol between the transmitter and the control module. Removing the battery resets the transmitter's code counter, which puts it out of sync with the module. The module will ignore commands from an out-of-sync remote — the LED on the remote may flash, but the vehicle won't respond. Re-enter programming mode on the control module and press the transmitter button to re-establish the code handshake; refer to your specific model's guide for the exact sequence, which typically starts with three presses of the override/valet button.

Keyless entry range reduced immediately after installing a fresh cell

A new lithium-polymer cell ships at storage voltage — typically around 3.6V — not at a full 3.7V charge. At storage voltage, the transmitter's RF output power is slightly lower, which shortens effective range. This is normal and not a fault with the cell. Use the remote a few times over the first day to allow the cell to settle; if the system has a dedicated lock/unlock range that still falls short of the original, check that the antenna wire on the control module side is routed away from metal bodywork.