Philips AT750 Electric Shaver Replacement Battery KR112RRL 3.7V

Philips AT750 Series — 3.7V Li-ion Replacement Battery (KR112RRL)

This is a 3.7V 650mAh Li-ion battery for the Philips AT750, AT751, AT752, and AT753 cordless rotary shavers, plus nine additional AT-series models. It replaces the original cell when the shaver no longer holds charge or fails to power on cordlessly. Voltage and capacity match the OEM spec exactly.

• AT750 series compatibility: These models share the same internal cell format, voltage rail, and BMS handshake. The 43.10 × 14.40 × 14.40mm cell dimensions and 3.7V nominal voltage are consistent across the AT750 to AT753 range, which is why one replacement covers the full lineup.
• Bench tested on actual hardware: We cycled this cell through the AT750 charging circuit and confirmed the BMS accepted the charge profile without tripping protection. Discharge curves under rotary motor load stayed within spec until cutoff.
• Moisture and charging port care: Dry the charging port completely before connecting to the charger after rinsing. Water bridging the charging contacts triggers a BMS protection fault the shaver reports as a dead battery — not a charging error — which misleads most users into thinking the new battery has failed.

Motor speed dropping before the low-battery indicator activates

The AT750's rotary motor draws a short current spike on each head rotation cycle. As the cell ages, internal resistance rises and voltage sags under that load — the motor slows noticeably before the battery indicator registers low. The shaver's fuel gauge reads cell voltage at rest, not under load, so the two readings diverge. A new cell with low internal resistance eliminates the sag and restores consistent motor speed.

Capacity fade from daily partial charging on the AT750

Plugging the AT750 into the dock after every shave without depleting it first compresses the charge cycle into a narrow voltage band. Li-ion cells cycled repeatedly between 80–100% lose active lithium inventory faster than cells allowed to discharge more fully. The battery indicator drifts as a result — showing full charge while actual usable capacity is substantially lower. If the shaver behaves this way, run it to automatic cutoff twice before resuming dock charging to help recalibrate the indicator.