# JYJZPB 2 Pack 6.5Ah Replace Battery

- Manufacturer: JYJZPB
- Tier: C
- Price: $28.00
- Stated capacity: 6.5 Ah
- Amazon listing: https://www.amazon.com/dp/B093Q4K7PN?tag=lithiumsteppe-20
- Battery page: https://www.lithiumsteppe.com/battery/jyjzpb_65ah

## Summary

All-around "not great" pack. Could work on a drill or other low-power tool.

## Ratings

- **Honesty**: 2.4/5 — Actual capacity 3.9Ah, far short of the 6.5Ah claim.
- **Durability**: 1/5 (teardown 0.5/5, cycling 1.4/5) — Low-quality tool contacts risk getting melted plastic on your tool.
  - Teardown notes: Same cheap pack design as jnfkldsb and velgonyx -- easily-bent tool electrodes, plastic melts onto tool contacts.
- **Capacity**: 3/5 — Actual capacity 3.9Ah, far short of the 6.5Ah claim.
- **Power**: 0.5/5 — Poor cycling test performance. Not suited for heavy use.
- **Safety**: 2/5 — No safety features; battery started a sustained plastic fire during the failure test.

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

## Testing statistics

- Stated capacity: 6.5 Ah (117 Wh @ 18 V)
- Measured capacity: 3.9 Ah (69.8 Wh @ 18 V)
- Pack internal resistance: 67.8 mOhm
- High-power cycles survived: 5
- Peak sustained power: 961 W
- Energy delivered (failure test): 40.2 Wh

## Cell notes

Lishen LR1865LA. 20-30A max continuous discharge. 2000mAh capacity.

## Test data

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

- **Pack Internal Resistance Test** (rinternal): Pack Resistance: 67.8 mOhm (average value of pack resistance between 17.5 and 18.5 V)
  - CSV: [rinternal.csv](tests/rinternal.csv)
  - Bench source file: jyjzpb_65ah/rinternal_jyjzpb_65ah_260514-17-49-29_0.csv
- **Capacity Test** (capacity): Capacity: 69.8 Wh (60% of stated 6.5 Ah @ 18V Nominal)
  - CSV: [capacity.csv](tests/capacity.csv)
  - Bench source file: jyjzpb_65ah/capacity_jyjzpb_65ah_260519-11-23-48_0.csv
- **Cycling Test** (performance): High-power cycles survived: 5. Failure mode: Battery thermistor reached cutoff
  - CSV: [performance.csv](tests/performance.csv)
  - Bench source file: jyjzpb_65ah/performance_jyjzpb_65ah_260521-10-03-08_0.csv
- **Failure Test** (failure): Energy discharged: 40.2 Wh, Peak power: 961 W
  - CSV: [failure.csv](tests/failure.csv)
  - Bench source file: jyjzpb_65ah/failure_jyjzpb_65ah_260521-11-10-07_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 — Common cheap pack design, shared by multiple budget battery brands
- Teardown 2: photos/teardown_2.jpg — Easily-bent electrodes crap out early
- Teardown 3: photos/teardown_3.jpg — Pack exterior destroyed after failure test. Plastic melts easily
- Teardown 4: photos/teardown_4.jpg
- Teardown 5: photos/teardown_5.jpg — Melted busbars
- Teardown 6: photos/teardown_6.jpg
- Teardown 7: photos/teardown_7.jpg — Cell label: +LS LR1865LA E93103 20429030 2000mAh

## 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: 2026-07-16T19:29:36.895Z (site commit a353b4a)
Contact: https://www.lithiumsteppe.com/contact
