About this replacement
Testo 480 — 3.7V Li-ion Replacement Battery (0515 0043)
This is a 3.7V 3600mAh Li-ion battery for the Testo 480 digital light meter. It replaces OEM part number 0515 0043 and fits the 480 directly. The Testo 480 is a handheld illuminance and luminous intensity meter used in industrial, commercial, and laboratory lighting assessments.
- Testo 480 platform fit: The 480 draws power through a single-cell Li-ion pack with a BMS that communicates state-of-charge to the instrument firmware. Voltage rail, connector pinout, and BMS handshake all match the original pack specification.
- Bench tested on actual hardware: We ran this pack through probe module initialisation and sustained sensor logging on the 480. The BMS handled the probe power-up current spike without tripping, and voltage held steady across multi-point measurement sequences.
- Post-install calibration cycle: After fitting this battery, run a full calibration cycle through the Testo 480 instrument menu before field use. The instrument maps battery state during calibration — skipping this causes premature low-battery warnings to appear during the first measurement session, even with a fully charged pack.
Testo 480 shutting down mid-measurement with a charged battery
This happens when the BMS trips on a sustained current draw during continuous sensor logging. The 480's probe modules pull additional current during active measurement, and an aged cell with elevated internal resistance can drop below the BMS cutoff threshold even when the display shows remaining charge. The pack shuts the instrument down as a protection response, not because capacity is exhausted. A fresh cell with lower internal resistance eliminates this dropout under the same sustained load.
Testo 480 not recognising a new pack after the instrument sat unused
If the 480 or the replacement pack sat unused for several months, the battery's BMS may have entered sleep mode after self-discharge dropped the cell below the recovery voltage threshold. The instrument sees no communication from the BMS and fails to power on or shows a battery error. Connect the pack to the Testo charger for 15–20 minutes before inserting it into the meter — this wakes the BMS and restores communication. Once the BMS is active, the instrument should recognise the pack and charge normally to 4.2V.