Battery Upgrade Results: How Molicel P50B and P30B Cells Outperform Stock DeWalt Packs
Our customer Mike recently tested two DeWalt packs after upgrading with premium Molicel P-series cells from RenewSpark. He ran controlled constant-load discharges and shared his graphs and notes. Below are the results, and the parts to do the same yourself.
Test #1 — DeWalt DCB206 (6Ah) Upgraded with Molicel P50B
- Load: 20A constant discharge
- Cutoff: 15V (to avoid stressing the pack)
- Charge method: RC charger to 21.0V (4.2V/cell) for consistency
Mike reports the upgraded pack held a higher voltage for longer and was “still going strong” at the cutoff point—evidence of lower internal resistance and greater usable capacity under heavy draw.
| Metric | Stock DCB206 | Upgraded (P50B) |
|---|---|---|
| Voltage sag @ 20A | Drops early | Stays higher, longer |
| Runtime to 15V | Shorter | ~15–25% longer* |
| Cell type | Factory (2022) | Molicel P50B 21700 |
*Improvement depends on pack condition, BMS, welds, and tool load.
Test #2 — DeWalt DCB203 (2Ah) Upgraded with Molicel P30B
Mike compared a brand-new 2025 DCB203 2Ah pack with the same pack rebuilt using Molicel P30B cells. His feedback: the original felt weak in 20V tools, while the upgraded pack felt “super strong.”
“Before, the smaller DCB203 pack was very weak in my 20V tools, but with this newly rebuilt pack it’s super strong.” — Mike
The 21700 cells from these tests
Build it yourself
Everything used in these tests is available as parts. Pick the cell that matches your pack’s format, then the kit for your platform:
- BAK N18650COP 18650 Cells — for 18650 packs
- Molicel P42A 21700 Cells — for 21700 packs
- Molicel P50B 21700 Cells (out of stock)
- Rebuild kits — BMS, housing, nickel and hardware as a matched set
- BMS Boards
- Pure Nickel Strip 0.2×10 mm
- 21700 Fish-Paper Insulator Rings
- Kapton Tape
Why upgrade the cells?
- Real-world results: Customer-verified graphs under heavy loads
- More runtime: Often 15–25% more usable capacity*
- Stronger under load: Reduced voltage sag for demanding tools
- Second life for the pack: The shell, board and terminals usually outlast the cells by years
*Actual improvement varies by pack health, BMS, weld quality, and tool usage.
Related Reading
- Power tool battery cell guide: what each brand uses
- 21700 vs 18650: differences and when to use each
- How to rebuild a DeWalt DCB205 20V MAX pack
- How to tell whether a used cell is still good
Safety note: pack work requires proper tools and knowledge — a spot welder, insulation, polarity checks, and correct BMS wiring. Never solder directly to a cell can, and recycle any cell that is dented, swollen, or below 2.0V.
