Energizer H280S Replacement Battery 3.7V 1900mAh Li-ion

Energizer HARDCASE H280S — 3.7V Li-ion Replacement Battery (H280S)

This 3.7V, 1900mAh Li-ion battery replaces the original cell in the Energizer HARDCASE H280S smartphone. The H280S part number confirms a direct match to the HARDCASE H280S model — same connector, same physical footprint at 64.80 × 46.20 × 6.30mm. Capacity is sourced from the product data at 7.03Wh.

• HARDCASE H280S platform fit: The H280S battery uses a fixed connector pinout and BMS handshake specific to this rugged smartphone line. Swapping to a generic cell with a mismatched protection circuit will trigger charge refusal at the charge IC — this cell carries the correct BMS profile for the H280S charge controller.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the H280S platform. The BMS held within spec across both full-current charge and low-current trickle phases, with no cutoff trips during normal screen-on load.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated state — preventing early percentage-jump errors.

Sudden shutdown at 20–30% on the replacement cell

The H280S fuel gauge IC retains the discharge curve from the old, degraded cell after a swap. When the new cell hits a voltage point the IC associates with a steep drop on the old curve, it signals a low-battery shutdown — even though real capacity remains. The modem and display together draw enough current to cause a brief voltage sag that tips the IC past its cutoff threshold. One full discharge to 0% and a complete charge cycle forces the coulomb counter to relearn the new cell's actual curve.

USB charging not accepted on the first connection after replacement

A new cell sitting at storage voltage — typically 3.6–3.7V — can cause the charge IC to stall on handshake if the BMS hasn't completed its initialisation sequence. Plug in the cable and leave the phone off for 10–15 minutes before attempting a power-on; the charge IC needs to see a stable input without load negotiation running simultaneously. If the charging indicator still doesn't appear, disconnect, wait 30 seconds, and reconnect — this resets the USB enumeration on the charge controller. The cell should accept current once the BMS clears its pre-charge gate above 3.0V.