FG5965-20 AMX MVP-8400 Compatible Battery 7.4V 3600mAh

AMX MVP-8400 Modero ViewPoint Touch Panel — 7.4V Li-Polymer Replacement Battery (FG5965-20)

This 7.4V 3600mAh lithium-polymer pack replaces the OEM FG5965-20 battery in the AMX MVP-8400 and MVP-8400i Modero ViewPoint touch panels. These panels are wall-mounted or handheld control interfaces used in professional AV installations to manage room systems, switching, and device control. Capacity is 3600mAh (26.64Wh) — matched to the original specification.

• MVP-8400 and MVP-8400i compatibility: Both panels share the same battery bay geometry, connector pinout, and BMS handshake protocol. The MVP-8400i adds wireless communication hardware, which draws slightly more current during active RF transmission, but both units run on the same 7.4V cell configuration and accept this pack without modification.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the MVP-8400 platform and confirmed the BMS negotiated correctly with the panel's charge management circuit. The protection board engaged at expected thresholds — no false low-battery flags during the test sessions.
• Post-install calibration on the MVP-8400: After fitting this pack, run the panel through a full power cycle and allow the charge indicator to update across one complete charge-discharge pass. The MVP-8400 maps battery state against cell voltage during active use — skipping this step causes the fuel gauge to report incorrect percentages and trigger premature low-battery warnings during AV sessions.

BMS lockout on the MVP-8400 after the panel sat unused in a carry bag for months

Lithium-polymer cells self-discharge during storage. If the MVP-8400 sits unused long enough, the cell voltage drops below the BMS's minimum recovery threshold — typically around 2.5V per cell. At that point, the protection circuit locks out charging entirely as a safety measure. Connecting the panel to its dock or USB charger will show no charging activity, and the screen may not power on at all. To recover, apply a slow pre-charge using a compatible Li-Po charger set to a recovery or trickle mode before reinserting the pack into the panel.

MVP-8400 display showing an unstable or jumping battery percentage after a new pack is fitted

The panel's battery indicator is calibrated against the voltage curve of the original cell. A new pack with a fresh, full charge presents a slightly different resting voltage profile than a partially aged cell — the panel's state-of-charge logic hasn't mapped it yet. This causes the percentage display to jump or read inconsistently during the first few cycles. Run two full charge-discharge cycles through normal panel use and the voltage-to-percentage mapping will stabilise. After the second full cycle, the indicator should read consistently within the expected range at rest voltage.