About this replacement
LUX-TOOLS AGS 7.2 LI / A-GS 7.2 Li — 7.2V Li-ion Replacement Battery
This 7.2V, 2000mAh Li-ion battery replaces the original pack on the LUX-TOOLS AGS 7.2 LI and A-GS 7.2 Li cordless angle grinders. It fits the compact battery housing on both model designations and runs the same 7.2V cell stack the tool's BMS expects. Dimensions match the OEM pack at 86.55 × 65.10 × 42.30mm.
- AGS 7.2 LI and A-GS 7.2 Li compatibility: Both model names refer to the same compact angle grinder platform. They share identical battery bay geometry, the same 7.2V voltage rail, and the same BMS communication handshake — one battery covers both.
- Bench tested on actual hardware: We ran the pack through motor-start inrush cycles on the grinder platform. The BMS held through repeated cold trigger pulls without tripping and recovered cell voltage cleanly between bursts.
- Break-in load for angle grinder cells: On first use, run the grinder at light cutting load for two full discharge-charge cycles before pushing into sustained metal grinding. This lets the BMS profile the motor's inrush current draw and set overcurrent thresholds accurately before heavy use.
BMS cutoff on trigger pull during grinding inrush
Angle grinders draw a sharp current spike the moment the disc spins up from rest. On a 7.2V pack, that inrush can briefly exceed the BMS overcurrent threshold, cutting the tool dead mid-start. This is more pronounced when the disc is already under contact with a workpiece at the moment of trigger pull. To clear the trip, release the trigger fully, wait three seconds, and restart the grinder off the material before bringing it to the cut.
Grinder bogs and loses torque mid-cut
If the tool starts normally but loses power and slows under load, the cause is usually voltage sag — the cell rail drops under sustained current draw, and the BMS throttles output before the low-voltage cutoff triggers. On a 7.2V pack, check that the battery contacts and terminal pins in the bay are clean and seated firmly; even 0.1Ω of contact resistance compounds sag noticeably at this voltage. If contacts are clean and sag persists, the cells are likely below serviceable capacity — rest the pack for ten minutes and retest with a voltmeter. A healthy pack at rest should read at or above 8.0V after a full charge.