Robot vacuum battery replacement & rebuild

Robot vacuum batteries use lithium-ion cells that gradually degrade with every charge and discharge cycle. After approximately 500–800 full cycles — roughly two to three years of daily use — the chemical structure of the cells changes irreversibly. The cathode material loses its ability to hold lithium ions, and battery capacity begins to drop rapidly. A robot that once ran for 120 minutes now dies after just 20–30 minutes.

Another common issue is BMS (Battery Management System) board failure. The BMS monitors each cell's voltage, temperature and state of charge. If even one cell becomes unstable or its voltage drifts away from the rest, the BMS may lock out the entire battery pack as a safety precaution — the robot simply stops working even though the remaining cells are perfectly fine. The third frequent cause is cell swelling: when degraded cells start generating gas, they physically expand and can deform the battery housing. This is a dangerous condition that demands immediate attention. We address all of these scenarios in our service centre — complete cell replacement with new Li-ion cells plus a fresh BMS board.

The SATER battery rebuild process begins with thorough diagnostics. First, we measure each cell's voltage individually to determine how many cells have degraded and whether the BMS board is functioning correctly. We then fully disassemble the battery pack — detach the cells from their interconnects, remove the old BMS board and prepare the housing for the new components.

In the next stage we install new top-grade lithium-ion cells matching the original configuration. Every cell is tested before installation to ensure uniform capacity and internal resistance across the entire pack. We then spot-weld new interconnects and fit a fresh BMS board calibrated to the specific cell configuration. Finally, we run a full charge-discharge test, measuring actual capacity and verifying that the BMS correctly manages all protection parameters. This meticulous process ensures the rebuilt battery performs as well as — or better than — the original.