About this replacement
Nihon Kohden Edan SE-1 — 14.8V Li-ion Replacement Battery (HYTB-102)
This 14.8V, 2600mAh lithium-ion battery replaces the HYTB-102 pack in the Edan SE-1 portable 12-channel ECG machine. It also fits the Edan SE-3, SE-12 Express, and SE-100 series. All specs match the OEM pack: voltage, cell count, and BMS communication protocol.
- SE-1 / SE-3 / SE-12 / SE-100 platform fit: These four models share the same 14.8V four-cell architecture and identical connector pinout. The BMS in each unit reads cell voltage and temperature data from the same register set, so one pack covers the entire platform.
- Bench tested on actual hardware: We ran this pack through full charge and load cycles on an SE-1 unit. The BMS handshake completed on first power-on, charge IC accepted the cell without a chemistry mismatch fault, and the device cleared its internal self-test without manual intervention.
- Post-swap power-on sequence: After fitting this battery, let the SE-1 complete its full power-on self-test without pressing any keys or connecting a patient cable. The device runs a BMS verification loop at startup — interrupting it creates a false battery fault that persists until the next clean reboot.
Why the SE-1 shows a battery error after a confirmed full charge
The SE-1's charge IC applies a conservative acceptance threshold on cells it hasn't profiled before. A new pack fresh from storage may sit just below the OEM state-of-charge threshold the BMS uses to clear the fault flag. This is not a defective cell — it's the BMS requiring one complete charge-discharge cycle to calibrate its capacity estimate. Run one full discharge under normal device use, then recharge to 100%. The fault clears after that cycle completes and the charge IC logs the cell's actual capacity.
SE-1 won't power on after the replacement battery sat in storage
Li-ion cells self-discharge during storage. If the pack voltage drops below approximately 10V — roughly 2.5V per cell — the BMS enters a deep-discharge lockout state and blocks current output entirely as a protection measure. The SE-1 will show no response at all: no boot screen, no LED, no sound. Connect the device to mains power via its AC adapter and leave it charging for a minimum of two hours before attempting to power on. This allows the charge IC to pre-charge the cells above the BMS recovery threshold, typically around 11.2V, at which point normal charging and startup resume.