DHRM DHR930D 7.4V Medical Device Replacement Battery 13500mAh

DHRM DHR930D — 7.4V Li-ion Replacement Battery

This is a 7.4V 13500mAh (99.9Wh) lithium-ion battery for the DHRM DHR930D and DHR930-D portable medical device. It replaces the original cell pack when capacity has degraded from repeated charge cycles. No OEM part number applies to this unit.

• DHR930D and DHR930-D compatibility: Both model variants use the same 7.4V two-cell Li-ion pack, the same connector pinout, and the same BMS handshake protocol — one battery fits both without modification.
• Bench tested on actual hardware: We cycled this pack through charge, hold, and load discharge. The BMS negotiated correctly, protection thresholds tripped at expected voltages, and cell balance held across the pack throughout testing.
• Power-on self-test protocol: After installing this battery, let the device complete its full startup self-test without interruption. Medical device firmware runs a BMS verification pass at boot — cutting power mid-sequence stores a false battery fault that persists until the next clean reboot.

DHR930D shutting off unexpectedly in the first ten cycles

Medical device load profiles draw harder on new cells than on broken-in ones, because the BMS applies tighter voltage-sag limits until it has learned the cell's internal resistance. During the first ten charge-discharge cycles, the pack's internal resistance reads higher than it will once the cells settle. The BMS interprets that sag as a low-state-of-charge condition and trips the cutoff early. Run the device through at least one full charge-discharge cycle before clinical use — this gives the BMS enough data to calibrate its cutoff threshold accurately.

Charge indicator stalling below 100% on the first charge

On a new cell, the charge IC applies a conservative upper voltage limit until it has confirmed the pack's chemistry response. This causes the indicator to plateau at 95–98% and hold there rather than stepping to full. It is not a faulty cell — the charge IC is running a cautious completion pass. Let the charger finish the full cycle without interrupting it. After one complete charge, the IC recalibrates and subsequent cycles reach 100% normally.