Here are some results of my torture testing
China HiPower 10 Ahr cells.
More results will be posted in the future.
Short story: After getting bottom balanced they stayed well balanced.
No BMS was used (unless you count the human that checked voltages at
the beginning and end of every test).
Spec for these cells was 10C continuous, which they did.
Running at 11C vented and ruined 2 cells.
These cells did well, and are cheaper than most.
China High Power is coming out with a new version of these cells
that are supposed to perform better.
V0 V1 V2 V3
3.29 3.30 3.30 3.27 As delivered
3.24 3.29 3.29 2.93 0.36 out of balance after about 50 A for about 4 min (only 33% capacity!).
Cells were obviously not delivered in balance.
2.99 2.99 2.99 2.96 After bottom balance
3.34 3.34 3.33 3.33 2 hrs after charge
3.33 3.33 3.33 3.33 12 hrs after charge
3.22 3.22 3.22 3.22 8C for 4+ min right after (53%+ capacity)
3.22 3.23 3.22 3.22 10 hrs rest
3.33 3.33 3.33 3.33 About 24 hours after charge
3.18 3.20 3.19 3.16 100 A 5.5 min (92% capacity!). >=10.0 V most of time 9.5 at end
3.19 3.21 3.21 3.17 After a short rest
3.29 3.33 3.33 3.29 After charged up
2.73 3.21 3.21 2.86 110A about 4:15 let smoke out! 110A was over spec! One cell was 93 Celsius!
2.08 3.21 3.21 2.18 Sat for a week. Two cells bad self discharge now and are clearly ruined
2.66 2.88 After series discharge one of the 'good' cells has spit out some
electrolyte and now 0.22 V out of balance after running over spec
2.75 2.71 Bottom balanced, discharged individually to 2.0V then 2 hours rest
3.27 3.26 After a few 50A bursts of charging
3.33 3.33 Charged up
3.28 3.28 100A 2 min (33% capacity), >=4.4V whole time
3.32 3.32 After 50A charge
3.29 3.28 100A for 2 min tighter connnection raised Voltage 4.2 to 4.5 and current
100A to 120A. Cell 2 is 5 Celsius cooler.
3.32 3.33 Charged up
3.28 3.27 100A for 2 min after 5 to 4.6V
3.35 3.36 Just after ~40A ~5 min quick charge
3.33 3.34 100A for 2 min before, 5.5 to 5.2V. Voltage rise due to warmer cells.
3.30 3.29 ~40A ~5min quick charge held to 7.3V
3.34 3.35 100A for 1:20 terminated early due to high temp. 5.6 to 5.2V.
On 3rd round of 100 A out, 40 A in cells overheated