About this replacement
Sichler PR-030 / PR-025 / PR-041 / PR-127 — 7.4V Li-Polymer Replacement Battery (PL062018-2S)
This is a 7.4V, 1800mAh lithium-polymer replacement battery for the Sichler PR-030 robotic vacuum cleaner and compatible models including the PR-025, PR-041, and PR-127. It replaces OEM part number PL062018-2S. Fit it when the original cell no longer holds charge through a full cleaning cycle.
- PR-030, PR-025, PR-041, PR-127 compatibility: These models share the same 7.4V two-cell lithium-polymer configuration, connector pinout, and BMS handshake protocol — which is why one cell number covers all of them. Swapping between models in this family does not require any adapter or firmware change.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on a PR-series unit and confirmed the BMS negotiated correctly on first connect — no charge refusal, no protection-circuit lockout. Voltage under motor load stayed within the 6.8–8.4V operating window throughout.
- Dock charging habit on robotic vacuums: Do not leave the PR-030 sitting on the charging dock between sessions. Continuous trickle charge on a lithium-polymer cell compresses the usable capacity window over time. Charge to full, then remove from the dock until the next run.
Suction dropping before the battery indicator reaches low on the PR-030
This happens because the motor draws more current than rated whenever airflow is restricted — a partially clogged filter is the most common trigger. As current demand rises, the BMS may pull cell voltage below the motor controller's threshold before the fuel gauge registers a low reading. The indicator reads state-of-charge, not instantaneous load voltage — those are different measurements. Clean or replace the filter first, then retest; if suction holds, the battery is not the fault.
Motor cuts out mid-run then recovers after a few seconds
This is a BMS overcurrent trip, not a flat battery. When the PR-030 hits a carpet edge or a debris blockage, the motor momentarily stalls and current spikes. The protection circuit opens to prevent cell damage, then resets once current drops — usually within two to five seconds. If this happens repeatedly on open hard floor with a clean filter, measure resting cell voltage after a full charge; it should read 8.3–8.4V. A cell sitting below 8.0V at rest after a full charge cycle has degraded and needs replacement.