Robot vacuum battery rebuild
Robot vacuum battery rebuilds with new lithium-ion cells and a fresh BMS board: Roborock S/Q/G, iRobot Roomba, Dreame, Ecovacs.
After 1.5–3 years of daily use a robot vacuum battery starts giving up: cleaning runtime drops from 90–120 minutes to 15–25, the robot dies mid-cycle on the carpet, refuses to charge past 80%, or after a deep discharge gets stuck in BMS lockout and will no longer power on. The most dangerous failure mode is swollen cells distending the pack housing — a robot in that state must be taken out of service immediately. We rebuild battery packs for every major robot vacuum brand: iRobot Roomba (NiMH on the 600 series, lithium-ion on the i/j/s series at 3300 mAh and up), Roborock S/Q/G with 5200 or 5800 mAh lithium-ion cells, Dreame X20/L20 (5200 mAh), Ecovacs T8/T10/X1 (5200 mAh), Eufy X10 Pro (3200 mAh), Xiaomi Mi (5200 mAh) and Samsung Jet Bot (60 Wh lithium-ion). Diagnostics start with a per-cell voltage measurement — often a single deeply degraded cell is dragging the rest of the pack down and triggering the BMS lockout. During the rebuild we restore the original pack configuration (4S1P for 14.4 V Roomba packs, 4S2P for Roborock 14.4 V 5200 mAh packs and so on), fit a fresh BMS board with proper overcharge, deep-discharge, short-circuit and thermal protection, and run a full charge-discharge cycle to measure real capacity. On selected models, latest-generation cells let us deliberately exceed factory capacity — for example, fitting 5800 mAh cells into a stock 5200 mAh Roborock pack. All battery work carries a 6-month warranty that covers both the cells and the BMS board. We accept and return packs in person only — lithium-ion batteries are not shipped or received by post.
Popular models we repair
- iRobot Roomba 14.4V Li-ion (i3/i7/j7/s9)
- Roborock 14.4V 5200mAh (S5/S6/S7/S8)
- Xiaomi 14.4V (Mi Robot, Vacuum Mop)
- Ecovacs 14.4V/14.8V (Deebot N8/T8/X1/X2)
- Dreame 14.4V (L10/L20/D9)
- Samsung 21.6V (Jet Bot)
- Eufy 14.4V
Common problems we fix
- Battery will not hold a charge past 20 minutes — cell degradation
- Swollen cells pushing the case open — dangerous condition
- BMS lockout after deep discharge — robot will not power on
- Robot dies mid-cycle at 30–50% charge level
- Battery will not charge past 80% — cell imbalance
- Charging LED flashes an error pattern — fault cannot be identified
- Reduced power on max mode — cell cannot sustain the load
- Sudden shutdown on carpet — high current draw issue
Detailed problem guides
Pick a symptom — we walk through the causes, what you can check yourself, and when to bring it in.
Why robot vacuum batteries fail after 1–2 years
The lithium-ion cells inside robot vacuum battery packs gradually degrade with every charge and discharge cycle. After approximately 500–800 full cycles — roughly 1.5 to 3 years of daily use — the cell chemistry changes irreversibly. The cathode material loses its ability to hold lithium ions efficiently, and battery capacity begins to drop rapidly.
Robots that originally ran for 90–120 minutes on a single charge now die after just 15–25 minutes. Moreover, degraded cells often lose capacity unevenly — one cell group may be nearly healthy while another is completely worn out. This creates a voltage imbalance that the BMS board interprets as a fault and, as a safety precaution, may lock out the entire pack. An even more dangerous condition occurs when degraded cells start generating gas and physically swell — this deforms the housing and creates a direct fire hazard. A robot running on a swollen battery must be shut down immediately. All of these scenarios are resolved by a complete cell replacement and a fresh BMS board.
Our cell-level rebuild process
The rebuild begins with measuring each cell's voltage individually, which lets us pinpoint exactly how many cells have degraded and whether the BMS board is functioning correctly. After diagnostics we fully disassemble the battery pack — detach the cells from their spot-weld points, remove the old BMS board and prepare the housing for new components.
We then install new lithium-ion cells in the original series-parallel configuration (for example, 4S1P for iRobot Roomba 14.4 V or 4S2P for Roborock 14.4 V 5200 mAh packs). Every cell is tested before installation to ensure uniform capacity and internal resistance across the entire pack. After spot-welding new interconnects we fit a fresh BMS board calibrated to the specific configuration. Finally, we run a full charge-discharge test, measuring actual capacity and verifying that the BMS correctly manages all protection parameters — overcharge, deep discharge, short circuit and thermal protection. The result is a battery that performs as well as or better than the original, backed by a 6-month warranty.
Pricing & warranty
Battery replacement warranty: 6 months.
If the repair cost changes during the process, the technician will call to agree on the new price. No work is done without your consent.
Frequently asked questions
Why customers choose SATER
- Custom-built battery assemblies. We design and assemble packs for the exact device — no 'close enough' substitutes.
- Sony, Samsung, LG, Panasonic, Molicel cells. Only top-tier cells — each one capacity-tested before assembly.
- Batteries for robots, power tools, laptops. We build packs for any device that runs on lithium batteries.
- 30+ years of experience. The service centre has been operating since 1993.
- We serve all of Latvia. Electronics service centre in Riga — we accept devices from anywhere in the country.