# YBT 8.0Ah Replacement for DW20V MAX Battery

- Manufacturer: YBT
- Tier: Retired
- Price: $26.50
- Stated capacity: 8 Ah
- Amazon listing: https://www.amazon.com/dp/B0G3PJSZF6?tag=lithiumsteppe-20
- Battery page: https://www.lithiumsteppe.com/battery/ybt_8ah

## Summary

An all-around solid pack with high capacity and great electrical performance, nearly matching DeWalt's own. Held back by mid-tier electrical contacts, lack of safety features, and mystery-18650 cells.

## Ratings

- **Honesty**: 2.5/5 — Actual capacity 4.85Ah. It's just not possible to fit 8.0Ah into 10 18650s!
- **Durability**: 2.3/5 (teardown 2/5, cycling 2.6/5) — Flimsy tool contacts could easily get bent out of place. Otherwise solid electrically.
  - Teardown notes: Flimsy tool contacts that easily bend out of place. Otherwise solid electrical construction.
- **Capacity**: 4/5 — Actual capacity 4.85Ah.
- **Power**: 4/5 — Very high-performing pack. The mystery cells can really take a beating.
- **Safety**: 3/5 — No obvious failure modes, but also no safety features. Safe to use.

Scoring rules: https://www.lithiumsteppe.com/methodology

## Testing statistics

- Stated capacity: 8 Ah (144 Wh @ 18 V)
- Measured capacity: 4.9 Ah (87.5 Wh @ 18 V)
- Pack internal resistance: 69.3 mOhm
- High-power cycles survived: 10
- Peak sustained power: 943 W
- Energy delivered (failure test): 42.3 Wh

## Cell notes

Jiangxi Province Yunfuheng New Energy YFH18650-2500mAh. No available discharge performance data.

## Test data

Test procedures: https://www.lithiumsteppe.com/test-procedures

- **Pack Internal Resistance Test** (rinternal): Pack Resistance: 69.3 mOhm (average value of pack resistance between 17.5 and 18.5 V)
  - CSV: [rinternal.csv](tests/rinternal.csv)
  - Bench source file: ybt_8ah/rinternal_ybt_8ah_260512-15-07-26_0.csv
- **Capacity Test** (capacity): Capacity: 87.5 Wh (61% of stated 8 Ah @ 18V Nominal)
  - CSV: [capacity.csv](tests/capacity.csv)
  - Bench source file: ybt_8ah/capacity_ybt_8ah_260513-08-53-54_0.csv
- **Cycling Test** (performance): High-power cycles survived: 10. Failure mode: Battery thermistor reached cutoff
  - CSV: [performance.csv](tests/performance.csv)
  - Bench source file: ybt_8ah/performance_ybt_8ah_260518-11-19-03_0.csv
- **Failure Test** (failure): Energy discharged: 42.3 Wh, Peak power: 943 W
  - CSV: [failure.csv](tests/failure.csv)
  - Bench source file: ybt_8ah/failure_ybt_8ah_260518-14-22-19_0.csv

### CSV format

1 Hz samples. Lines starting with `#` are run metadata (test profile, battery profile, instrument identity, Arduino DAQ channel labels); the first non-`#` line is the column header. Columns vary by run date — Arduino DAQ columns (tc/v/r_ntc/fault) appear on runs logged since 2026-05-11.

- `ts_unix / ts_iso` — sample timestamp (Unix seconds / ISO-8601 local time)
- `elapsed_s` — seconds since test start
- `voltage_v` — pack voltage, V (4-wire remote sense)
- `current_a` — discharge current, A
- `active_power_w` — discharge power, W
- `discharged_ah / discharged_wh` — integrated charge / energy removed
- `phase / target / cycle` — load-profile phase name, setpoint, loop count
- `tc1_C..tc4_C` — Type-K thermocouple temperatures, Celsius (nan = channel absent, disabled, or faulted)
- `v0_V` — DeWalt C3 cell-tap voltage, V
- `v1_V` — DeWalt TH thermistor-pin voltage, V
- `r_ntc_ohms` — pack NTC thermistor resistance, ohms, derived per-tick from v1_V and pack voltage (DeWalt tool thermal cutoff reference: 2140 ohms)
- `fault1..fault4` — MAX31856 status byte per thermocouple, hex (00 = healthy)

## Photos

- Headline photo: photos/headline.png
- Teardown 1: photos/teardown_1.jpg — No damage to exterior of pack after failure test
- Teardown 2: photos/teardown_2.jpg — Heat accumulation at busbar to PCB transition
- Teardown 3: photos/teardown_3.jpg — De-soldered / melted busbar <-> PCB connection
- Teardown 4: photos/teardown_4.jpg — Cell label: YFH18650-2500mAh 25C15 25G153 9.25Wh

## Files in this dataset

- `README.md` — this file
- `site.json` — the published data record for this battery (machine-readable)
- `tests/{rinternal,capacity,performance,failure}.csv` — raw bench CSVs (see CSV format above)
- `photos/` — headline + teardown photos (captions above)
- `test_procedures.md` — the four bench tests
- `ranking_methodology.md` — how ratings are scored

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Source: Lithium Steppe (https://www.lithiumsteppe.com) — We test DeWalt-compatible power tool batteries on Amazon to guide your purchasing decisions.
Generated: 2026-07-16T19:29:38.518Z (site commit a353b4a)
Contact: https://www.lithiumsteppe.com/contact
