About this replacement
NIKKISO DDB-27 — 24V Ni-MH Replacement Battery (HHR-06TH20A1)
This is a 24V, 2000mAh Ni-MH replacement battery for the NIKKISO DDB-27 infusion pump. It fits the DDB-27 and DBB-27 models and matches the OEM part number HHR-06TH20A1. Capacity is rated at 48Wh from the product specification.
- DDB-27 and DBB-27 platform fit: Both model variants share the same 24V power rail, connector pinout, and BMS handshake protocol. One battery cell pack covers both.
- Bench tested on actual hardware: We cycled this cell through the DDB-27 charge controller and confirmed the BMS accepted the new pack without fault codes. The charge IC applied a conservative trickle profile on the first charge, which is normal behaviour for a new Ni-MH cell.
- Power-on self-test after installation: After fitting the new battery, let the pump complete its full startup self-test sequence without interruption. The DDB-27 runs a BMS verification routine at boot. Cutting power during this window causes a false battery fault that stays logged until the next full reboot cycle.
Low battery alarm triggering on the DDB-27 during active infusion
The DDB-27's BMS monitors cell voltage under load and compares it against a stored threshold calibrated for the OEM cell chemistry. A new Ni-MH cell has not yet established its internal resistance baseline, so voltage can sag briefly under the pump motor's draw. That sag trips the low-battery alarm even when the cell is fully charged. Running one complete charge-discharge cycle normalises the cell's voltage response and clears the recurring alarm.
Charge indicator not reaching 100% on the first charge cycle
The DDB-27 charge controller applies a conservative current limit when it encounters a new cell with no charge history. This is intentional — the charge IC holds back until it confirms the cell's temperature and voltage rise rate are within safe parameters. The indicator will plateau short of 100% on the first pass. Complete a second full charge cycle and the controller recalibrates its endpoint; the indicator should reach full charge. If it still stops early after two cycles, check cell voltage at the contacts — it should read 24V ± 0.5V at full charge.