MetroPCS 4G BL-53QH Replacement Battery 3.7V 1800mAh

MetroPCS 4G / MS870 — 3.7V Li-ion Replacement Battery (BL-53QH)

This is a 3.7V, 1800mAh Li-ion replacement battery for the MetroPCS 4G smartphone, also sold as the LGMS870. It replaces OEM part BL-53QH and EAC61878605. Swap it in when the original cell no longer holds charge through a normal day of calls, messaging, and app use.

• MS870 and 4G model compatibility: The MS870 and MetroPCS 4G share the same battery bay dimensions, connector pin-out, and BMS handshake protocol — one cell covers both. The 57.70 x 51.20 x 5.20mm footprint seats flush without modification.
• Bench tested on actual hardware: We ran this cell on an MS870 unit and monitored BMS cutoff behaviour across charge and discharge cycles. The protection circuit held voltage within expected parameters and tripped correctly at the low-voltage threshold — no false cutoffs under modem load.
• First-cycle fuel gauge reset: After installation, disable fast charging and run one full discharge-to-charge cycle. The fuel gauge IC on the MS870 calibrates its coulomb counter against the new cell's discharge curve. Skipping this step causes the reported percentage to drift against actual cell state.

Sudden shutdown at 20–30% on the MS870 after a cell swap

The MS870 uses a fuel gauge IC that maps voltage to percentage based on the original cell's discharge curve. A new cell has a slightly different curve, so the IC can misread remaining capacity. Under high load — active LTE, screen at full brightness — the phone pulls peak current and the new cell's voltage drops below the shutdown threshold before the gauge reaches 0%. One full discharge-charge cycle recalibrates the curve and moves the cutoff point back to where it should be.

Phone won't power on after the replacement cell sat in storage

Li-ion cells shipped or stored for extended periods can drop below 2.5V per cell. At that level, the BMS locks out charging as a safety measure and the phone shows nothing when you press power. Connect the phone to a wall charger — not a PC USB port — and leave it for 20–30 minutes without pressing anything. A wall adapter delivers enough current to nudge the BMS out of lockout mode. Once the charging LED activates, the cell is recovering and you can proceed with a normal charge cycle to 3.7V nominal.