18650 battery test 2011

A 2012 test can be found here

DSC_6200

In this test I have measured many different 18650 batteries and collected the data in bar graphs and curves. The above picture shows most of the cells I have tested.

Summary

Capacity: Measured capacity at 0.2 ampere discharge rate (This is the average from the two tested cells). This is not measured the same way as the manufacture specified capacity, i.e. it is not supposed to be exactly the same value.
Top: SB: Small button top, LB: Large button top, Flat: Flat top (See here for more information).
Bottom: A protected battery has a PCB at the bottom, on some batteries this has been strengthen with a metal plate.
Protected: Does the battery have a protection circuit? IMR batteries do not.
Max. Dis.: Maximum allowed discharge rate. This is only listed for batteries where it is specified, for all other batteries assume 2C.
Source: Where I got the battery.
Date: The month I got the battery.

Capacity

This chart show the average capacity of the tested cells.

Energy

This chart show the average energy of the tested cells.

EnergyDrop

In this chart I have taken the difference between 0.2 and 2 ampere energy bar and calculated the change in percent of total energy ((Energy@0.2A - Energy@2A) /Energy@0.2A). This high lights the difference on handling loads.



Physical dimensions

18650 batteries are not all the same size, they are supposed to be 18 mm in diameter and 65 mm long, but due to the added protection circuit they are up to 5 mm longer. These charts show the size of the largest of my test batteries (The difference is usual not more than 0.1 mm to 0.2 mm for a cell type).

SizeLength

SizeDiameter

Weight


Combined discharge curves

These curves can be very hard to read, due to the many cells in one chart. When in doubt about which cell a specific curve is, use the charts under each cell to confirm the cell type.

0.2 ampere discharge

Capacity-0.2A

Energy-0.2A



0.5 ampere discharge

Capacity-0.5A

Energy-0.5A



1 ampere discharge

Capacity-1A

Energy-1A



2 ampere discharge

Capacity-2A

Energy-2A



5 ampere discharge

Not all batteries can sustain 5 ampere discharge and few batteries are rated for it. Because some curves are missing the color of the curves are different from above.

Capacity-5A

Energy-5A



Curves and pictures for each cell

RediLast 2200 (Black)

RediLast-2200-top RediLast-2200-bottom
RediLast-2200-a
RediLast-2200-b

Specifications:

Capacity-RediLast-2200

Energy-RediLast-2200



RediLast 2600 (Black)

RediLast-2600-top RediLast-2600-bottom
RediLast-2600-a
RediLast-2600-b

Specifications:

Capacity-RediLast-2600

Energy-RediLast-2600



RediLast 2900 (Black)

RediLast-2900-top RediLast-2900-bottom
RediLast-2900-a
RediLast-2900-b

Specifications:

Capacity-RediLast-2900

Energy-RediLast-2900



AW IMR1600 (Red)

AW-1600-top AW-1600-bottom
AW-1600-a
AW-1600-b

This cell may have a low capacity, but it can supply very high currents.
Specifications:

Capacity-AW-1600

Energy-AW-1600



AW 2200 (Black)

AW-2200-top AW-2200-bottom
AW-2200-a
AW-2200-b

Capacity-AW-2200

Energy-AW-2200



AW 2600 (Black)

AW-2600-top AW-2600-bottom
AW-2600-a
AW-2600-b

Specifications:

Capacity-AW-2600

Energy-AW-2600




AW 2900 (Black)

AW-2900-top AW-2900-bottom
AW-2900-a
AW-2900-b

Specifications:

Capacity-AW-2900

Energy-AW-2900



ASUCELL 3000 (Yellow/black)

AsuCell-3000-top AsuCell-3000-bottom
AsuCell-3000-a
AsuCell-3000-b
AsuCell-3000-c

Capacity-AsuCell-3000

Energy-AsuCell-3000


TrustFire TF2400 (Black/red)

TrustFire-2400-top TrustFire-2400-bottom
TrustFire-2400-a
TrustFire-2400-b
TrustFire-2400-c

Capacity-TrustFire-2400

Energy-TrustFire-2400



FakeSony LR3000 (Black)

FakeSony-3000-top FakeSony-3000-bottom
FakeSony-3000-a
FakeSony-3000-b
FakeSony-3000-c

This cell combines all the worst parameters for a cheap cell:
1) Fake manufacture name
2) Large capacity variations
3) High internal resistance
It might be old cell or rejected cells that has got a new wrapper.

Capacity-FakeSony-3000

Energy-FakeSony-3000



Soshine 2800 (Black)

Soshine-2800-top Soshine-2800-bottom
Soshine-2800-a
Soshine-2800-b
Soshine-2800-c

Capacity-Soshine-2800

Energy-Soshine-2800



UltraFire BRC3600 (Black/white)

UltraFire-3600-top UltraFire-3600-bottom
UltraFire-3600-a
UltraFire-3600-b
UltraFire-3600-c

Capacity-UltraFire-3600

Energy-UltraFire-3600



Cytac 2400 (Blue/white)

Cytac-2400-top Cytac-2400-bottom
Cytac-2400-a
Cytac-2400-b
Cytac-2400-c

Capacity-Cytac-2400

Energy-Cytac-2400



Cytac 2600 (Blue)

Cytac-2600-top Cytac-2600-bottom
Cytac-2600-a
Cytac-2600-b
Cytac-2600-c

I have tested this cell in two batches and both has the same capacity, Cytac says this is because the cell are designed for high load and will show some extra capacity at low loads.

Capacity-Cytac-2600

Energy-Cytac-2600



Cytac 2900 (Red)

Cytac-2900-top Cytac-2900-bottom
Cytac-2900-a
Cytac-2900-b

Capacity-Cytac-2900

Energy-Cytac-2900



Tenergy 2600 (Cyan)

Tenergy-2600-top Tenergy-2600-bottom
Tenergy-2600-a
Tenergy-2600-b
Tenergy-2600-c

Specifications:

Capacity-Tenergy-2600

Energy-Tenergy-2600


Solarforce 2400 (White/blue)

Solarforce-2400-top Solarforce-2400-bottom
Solarforce-2400-a
Solarforce-2400-b
Solarforce-2400-c

Specifications:

Capacity-Solarforce-2400

Energy-Solarforce-2400



SpiderFire LC3000 (Gray)

SpiderFire-3000-top SpiderFire-3000-bottom
SpiderFire-3000-a
SpiderFire-3000-b
SpiderFire-3000-c

Capacity-SpiderFire-3000

Energy-SpiderFire-3000



Panasonic NCR2900 (Gray)
Panasonic-2900-top Panasonic-2900-bottom
Panasonic-2900-a
Panasonic-2900-b
Panasonic-2900-c

Capacity-Panasonic-2900

Energy-Panasonic-2900



Samsung ICR3000 (Purple)
Samsung-3000-top Samsung-3000-bottom
Samsung-3000-a
Samsung-3000-b

In the first two charts the cell is only charged with a normal LiIon charger, in the last two charts the cell is charged to full capacity using the CottonPickers charger.

Capacity-Samsung-3000

Energy-Samsung-3000

Capacity-Samsung-3000-4.35V

Energy-Samsung-3000-4.35V



TrustFire TR2400 (Gray)
TrustFire-2400-gray-top TrustFire-2400-gray-bottom
TrustFire-2400-gray-a
TrustFire-2400-gray-b
TrustFire-2400-gray-c

Capacity-TrustFire-2400-gray

Energy-TrustFire-2400-gray



Sources
TH: Tactical HID
AW: AW on cpf
DX: DealExtreme
BJ: Battery Junction
HKE: HKEquipment


Notes

For all battery types I have tested two different cells, they are called A and B in the graphs. All cells have been charged on a hobby charger with half the marked capacity as charge current and the charge is stopped when the current is 1/10 of the charge current. I.e. if the battery is marked 3000mAh it is charged with 1500mA and the charge is stopped when the current is down to 150mA.
This charge method will not reach the maximum capacity of the batteries, there might be space for a few mAh more. Batteries that are marked with too high capacity will be penalized with this charging method.

When I only use one curve for a battery, it is the curve from battery A.

All the discharging is done on a CBA and I frequently verify that the reading from the CBA matches readings taking with a voltmeter directly over the cell.

Both capacity and energy is done in one discharge, capacity is a summation of the current, energy is a summation of current*voltage.

Cytac batteries were supplied by Cytac for a review.