About this replacement
Blancett B2900 / B3000 — 3.6V Lithium Replacement Battery (B300028)
This 3.6V lithium battery replaces OEM part B300028 in the Blancett B2900 and B3000 portable survey and field measurement instruments. Capacity is 14500mAh (52.2Wh), matching the original cell specification. It fits the physical bay and connector used across both model variants.
- B2900 and B3000 compatibility: Both instruments share the same battery bay geometry, connector pinout, and BMS handshake protocol — which is why a single cell covers both. The voltage rail and communication lines are identical across the two platforms.
- Bench tested on actual hardware: We cycled this pack through a simulated field logging sequence, including probe initialisation and sustained sensor draw. The BMS held the voltage rail steady through the initialisation spike and did not trip into protection mode.
- Post-install calibration before first field use: After fitting this battery, run a full calibration cycle through the instrument's menu before taking it into the field. The B2900 and B3000 map battery state during calibration — skipping this step causes the instrument to throw premature low-battery warnings during the first measurement session, even with a fully charged pack.
BMS cutoff when the probe module initialises on the B2900
When the B2900 powers up a connected probe or sensor module, there is a brief current spike as the module's internal circuitry comes online. If the battery's BMS has a low trip threshold — or if the cell voltage is already sitting near the lower end of its range — that spike can push the BMS into protection mode, cutting power before the instrument finishes booting. This is not a firmware fault in the instrument. The fix is to ensure the pack is charged above 3.5V before probe attachment, and to power the instrument on before connecting the probe so the spike hits a stable rail.
Instrument readings resetting or drifting mid-logging session
If readings reset or the logging session interrupts itself during sustained field use, the cause is usually a voltage dropout under continuous sensor load — not a corrupt log or software fault. The instrument's processor monitors the supply rail, and if voltage dips below its internal threshold under load, it triggers a soft reset to protect data integrity. Check that the battery is not partially discharged before a long session. A fully charged cell should hold above 3.3V under the sustained draw typical of a logging sequence — if it drops below that, the pack has degraded and needs replacement.