In-House Cell Testing Methods

5a-45a load tests to 2.8v performed in-house on custom equipment

Close up on the above plot, note the lower bounds is 3.7v after 10s pulse drain of 45a, it is then allowed to rest for 10s to see the unloaded voltage spike up.

Open-source VESC based battery load testing system

Subscribe to our yt channel to see our upcoming video on how we used to create the above graphs.

Depending on the resistor and VESC combination, we anticipate it can load test at up to at least 100a continuously.

There is an individual cell version that allows all the way to 32s at once , based on existing vesc hardware.

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Ampace JP40 130 Cell Grading Data

Provided by DeadsitckDuck

Ampace JP40 (22710a 21700a) Spec Sheet

JP40 Spec Sheet PDF Download (3 page version)

Primary Specs

Model

JP40

(LT 22710A) (21700a)

Size

21700

Capacity mAh

4000

(Discharged to 2.5v at 0.2c)

Capacity wh

14.8wh

Nominal Voltage

3.7v

Internal Resistance

<4 mOhms

(AC Impedance 1000hz)

Fully Charged

4.2v

(CC/CV) 40ma cut-off

End of Discharge

2.75v

Minimum Voltage

2.5v

Standard Charging Current

2A

Standard Discharge Current

12A

1500 cycles to 80%+ capacity at standard rates

Fast Charging

8A

Max Continuous Discharge Rate

45A

(11.25 C rate) starting discharge at 25 Celsius

Temp Limited Discharge Rate

60A

(15 C rate) Temp Limit 80 Celsius

Pulse 5 sec Discharge Rate

140A

(35 C rate) Time Limited

Cycle Life Testing

10 min rest between cycles to 2.75v

2A Charge
12A Discharge

1500 Cycles

80%+ capacity remaining

2A Charge
30A Discharge

600 Cycles

60%+ capacity remaining

8A Charge
40A Discharge

400 Cycles

60%+ capacity remaining

External Conditions

Weight

69g

Diameter

21.07

+/- 0.15

Height

70.1

+/- 0.2

Charging Temp

0-60C

Discharge Temp

-30C to 75C

Storage conditions: 1 Month

5C to 45C

Storage conditions: 6 Months

0C to 45C

Storage conditions: 12 Months

20C to 25C

 

Ampace JP40

Grading Factors

 

All Cells

mAh

Typical Value

4100

Min

3950

Max

4200

 

 

wh

Typical Value

14.8

Min

14.4

Max

15.2

 

 

mOhms

Typical Value

2.7

Min

2.5

Max

9

 

 

Grams

Typical Value

67.3

Min

66.8

Max

67.7

 

Ampace JP40

Grading Factors

 

Per Box 130 Cells

mAh

Spec:

4000+

Typical +/-

20

Max     +/-

50

 

 

wh

Spec:

14.8

Typical +/-

0.2

Max     +/-

0.4

 

 

mOhms

Spec:

4

Typical +/-

0.1

Max     +/-

1

 

 

Grams

Spec:

67

Typical +/-

0.45

Max     +/-

0.55

 

Ultra Caps vs JP40 21700 Li-ion Performance Comparison

 

(li-ion general and super cap data from batteryuniversity.com)  

Li-ion general

Super capacitor

Li-ion JP40

  
Charge time 10–60 minutes 1–10 seconds 20 min to 80%  
Cycle life 500 and higher 1 million or 30,000h 1500 cycles to 80% capacity Full discharge at 12a, charge at 4a
Cell voltage 3.6V Nominal 2.3 to 2.75V Max 3.7v nominal Nominal voltage
Specific energy (Wh/kg) 120–240 wh/kg 5 wh/kg 211 wh/kg Typical Values
Specific power (W/kg) 1,000–3,000w/kg Up to 10,000 w/kg 7523 w/kg 140a 3.7v 5 sec rating, temp limited
Cost per kWh $250–$1,000 $10000 kw/h $324 kw/h At bulk pricing
Service life (industrial) 5 to 10 years 10-15 years 5 to 10 years  
Charge temperature 0 to 45°C (32°to 113°F) –40 to 65°C (–40 to 149°F) 0C to 75C  
Discharge temperature –20 to 60°C (–4 to 140°F) –40 to 65°C (–40 to 149°F) –30C to 80C  
Self-discharge (30 days) 5% or less High (5-40%) 2%