waitley 2 Pack 20V 9.0Ah Replacement Battery
Tier Bby waitley
Test published July 2026
Similar design to the waitley 6 Ah, but with 5 additional cells. Great current routing and a mechanical safety fuse, and flimsy tool contacts that can limit operational life. Less identifiable and less performance 18650s made this pack heat up and fail sooner, so it doesn't pull the same weight as the 6Ah.
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Actual capacity is 7.44 Ah, vs 9 Ah advertised.
Flimsy tool-contacts are still the primary failure mode, but otherwise robust.
7.44 Ah capacity.
Slightly underperformed compared to waitley 6 Ah, despite having 50% more cells.
The same thermal/mechanical fuse performs as expected. Less-well-known 18650 cells leave room for improvement
Testing Statistics
Cell notes
JT18650S G3A-5, a lesser-known Chinese 18650 cell; the tested cells carried an August 2024 date code.
Cycling Test
We cycle the batteries at high-power (800W for 20s on, then 20W for 6s off) to reflect their actual usage in high-load scenarios like circular saw use.
Capacity Test
We measure the amount of usable energy the pack supplies from 100% to 0% charge.
Pack Internal Resistance Test
Failure Test
The battery is stepped through 30s at increasing current levels, ignoring safety features like temperature and voltage warnings, until the pack fails catastrophically.
Teardown Photos
