Motorola CLIQ MB200 SNN5843 Replacement Battery 3.7V 1300mAh

Motorola CLIQ MB200 / Droid A855 — 3.7V Li-ion Replacement Battery (SNN5843)

This is a 3.7V, 1300mAh Li-ion cell built to replace the original SNN5843 / BP6X battery in the Motorola CLIQ MB200, Droid A855, and compatible Android handsets. It fits the same physical footprint — 49.95 × 45.50 × 5.70mm — and connects to the same three-pin BMS contact strip. Capacity is sourced from product data at 4.81Wh nominal.

• CLIQ MB200 and Droid A855 compatibility: Both handsets share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The SNN5843 and BP6X part numbers cross to the same cell specification, so one SKU covers both platforms without modification.
• Bench tested on actual hardware: We cycled this cell through the Droid A855 charge IC, monitoring BMS communication on the data line. The protection circuit tripped correctly at the low-voltage threshold and accepted a full charge cycle without error flags on the system side.
• Fuel gauge recalibration on first use: After fitting this cell, disable any fast-charge option for the first full discharge-to-charge cycle. The phone's coulomb counter is calibrated to the old cell's discharge curve — one slow cycle lets the fuel gauge IC map the new curve before high-current charging begins.

Why the Droid A855 shuts down suddenly at 20–30% after a cell swap

The Droid A855 fuel gauge IC tracks charge state using a coulomb counter trained on the original cell's voltage-versus-capacity curve. A new cell has a steeper voltage cliff in the lower charge band — voltage drops faster under modem and display load than the IC expects. When the measured voltage falls below the IC's shutdown threshold, the phone powers off even though the capacity reading still shows 20–30%. One complete slow discharge cycle re-anchors the counter to the new curve and resolves the premature cutoff.

Phone not powering on after the replacement cell sat in storage

Li-ion cells self-discharge during storage. If voltage has dropped below 2.5V per cell, the BMS enters lockout mode and blocks current flow to prevent damage to the depleted cell. The phone will not respond to the power button and may show no charge indicator. Connect to a wall adapter — not a USB port — and leave it for 20–30 minutes without pressing anything; the charge IC on the phone needs to push a small trickle current past the BMS lockout before the cell recovers to a voltage where normal charging resumes. Target recovery voltage is 3.0V before the charge IC switches to full rate.