# xiuqiyu 2-Pack 5.0Ah 100% True Capacity & Automotive Power Cell Replacement Battery

- Manufacturer: xiuqiyu
- Tier: B
- Price: $31.50
- Stated capacity: 5 Ah
- Amazon listing: https://www.amazon.com/dp/B0G8VM2TYP?tag=lithiumsteppe-20
- Battery page: https://www.lithiumsteppe.com/battery/xiuqiyu_5ah

## Summary

This battery is not for high-power applications, but it's absolutely solid. Fantastic construction, actually exceeds its stated capacity, and no safety issues. Nearly identical to the Lidaiax and Menssda packs, their low-current cells cannot sustain saw-level power output, but they are ideal packs for drill/impact driver use. Upgrade the cells and these become S/A-tier.

## Ratings

- **Honesty**: 5/5 — Actual capacity 5.2Ah - Xiuqiyu actually overdelivers on this claim!
- **Durability**: 3.3/5 (teardown 5/5, cycling 1.7/5) — Great mechanical construction. Robust tool contacts. Though cannot sustain high power due to cells overheating.
  - Teardown notes: Robust tool contacts and clean mechanical construction. Same well-built pack design as lidaiax and menssda.
- **Capacity**: 5/5 — Actual capacity 5.2Ah.
- **Power**: 1/5 — Low-current cells are not suited for hard power tool use.
- **Safety**: 4.5/5 — Great electrical construction, no red flags.

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

## Testing statistics

- Stated capacity: 5 Ah (90 Wh @ 18 V)
- Measured capacity: 5.2 Ah (94.4 Wh @ 18 V)
- Pack internal resistance: 68.0 mOhm
- High-power cycles survived: 6
- Peak sustained power: 825 W
- Energy delivered (failure test): 31.6 Wh

## Cell notes

SWY / Shineway manufacturer. Model unknown. Unbranded 18650 cell.

## Test data

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

- **Pack Internal Resistance Test** (rinternal): Pack Resistance: 68.0 mOhm (average value of pack resistance between 17.5 and 18.5 V)
  - CSV: [rinternal.csv](tests/rinternal.csv)
  - Bench source file: xiuqiyu_5ah/rinternal_xiuqiyu_5ah_260519-16-59-25_0.csv
- **Capacity Test** (capacity): Capacity: 94.4 Wh (105% of stated 5 Ah @ 18V Nominal)
  - CSV: [capacity.csv](tests/capacity.csv)
  - Bench source file: xiuqiyu_5ah/capacity_xiuqiyu_5ah_260520-09-24-01_0.csv
- **Cycling Test** (performance): High-power cycles survived: 6. Failure mode: Battery thermistor reached cutoff
  - CSV: [performance.csv](tests/performance.csv)
  - Bench source file: xiuqiyu_5ah/performance_xiuqiyu_5ah_260521-10-20-27_0.csv
- **Failure Test** (failure): Energy discharged: 31.6 Wh, Peak power: 825 W
  - CSV: [failure.csv](tests/failure.csv)
  - Bench source file: xiuqiyu_5ah/failure_xiuqiyu_5ah_260521-12-36-10_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 — Identical pack design to Menssda and Lidaiax
- Teardown 2: photos/teardown_2.jpg — High-quality electrodes, overall great pack construction
- Teardown 3: photos/teardown_3.jpg — Cell label: SWY 18650 2.7Ah 3.6V 9.36Wh 26A01Y05

## 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: 2026-07-16T19:29:38.689Z (site commit a353b4a)
Contact: https://www.lithiumsteppe.com/contact
