Test / Review: A123 26650 2500mAh (Green)

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HKJ
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Test / Review: A123 26650 2500mAh (Green)

A123 26650 2500mAh (Green)

DSC_0049

This is a battery that can deliver very high amount of power!

Official specifications:

  • Nominal Voltage: 3.3v
  • Nominal Capacity: 2.3A
  • Standard Charge: 3.6A
  • Max Charge: 10C
  • Max Allowable Charge Voltage: 4.2v Charge voltage is 3.6 volt
  • Max Discharge: 30C (Continuous)
  • Burst Discharge: 60C
  • Weight: 70g
  • Dimensions: 66.5mm x 26mm



The above current rating is much lower than the A123 datasheet is says: 70A continuous and 120A pulse.

A123%2026650%202500mAh%20(Green)-info

This battery is rated for 2500mAh (in A123 datasheet) and will deliver it, even at a 30A load, but the voltage is lower than the normal LiCoO2 batteries.

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DSC_0051 DSC_0050

On this battery the body is the plus connection.

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A123%2026650%202500mAh%20(Green)-Capacity

Same capacity at any load and very constant voltage during discharge, but the price for the high current ability is capacity.

A123%2026650%202500mAh%20(Green)-CapacityTimeHours

A123%2026650%202500mAh%20(Green)-CapacityTime

A123%2026650%202500mAh%20(Green)-Energy

A123%2026650%202500mAh%20(Green)-PowerLoadTime

A123%2026650%202500mAh%20(Green)-TripCurrent

A123%2026650%202500mAh%20(Green)-Charge

I have used the same 1A charging current as I do for most other batteries. This battery is designed for much faster charging, recommend charge current is 2.5A and max. charge current is 10A for a 12 minutes charge to 80% capacity.


Conclusion

This battery uses a "safe" chemistry, but this does not make the battery safe, any battery that can deliver 120A has to be very careful treated.
This is a very interesting battery for some applications, but due to the low voltage it is not really good for flashlights (leds need a lower Vf).
This battery can only rate as very good.



Notes and links

How is the test done and how to read the charts
How is a protected LiIon battery constructed
More about button top and flat top batteries

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

Edited by: sb56637 on 08/26/2014 - 17:45
texaspyro
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Actually, these batteries can be awesome in a direct drive light. They spend 90% of their charge between 3.1 and 3.3V… matches a 3.2 Vf LED almost perfectly.

Oh, and don’t let the specs fool you. They can output over 200A into a short circuit! I’ve seen them charged at a 100C rate and survive!

A 4S pack can jump start a car 20 times in 20 below zero weather:
http://www.youtube.com/watch?v=qcvmvrmTMMk

I have a 4S2P pack in my 15,000 lumen light. That light has a jumper cable connector…

A123 also makes some larger format batteries, including an awesome 20Ah pouch cell. Those provide the backup power (dual redundant 16S packs) in a 180,000 lumen light that I designed.

fishinfool
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Don wrote:

"But as I said long ago, you are more likely to be killed by a dead fish dropped by a seagull in the Sahara Desert than by a lithium ion

ZW99GT
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texaspyro wrote:
Actually, these batteries can be awesome in a direct drive light. They spend 90% of their charge between 3.1 and 3.3V… matches a 3.2 Vf LED almost perfectly.

Oh, and don’t let the specs fool you. They can output over 200A into a short circuit! I’ve seen them charged at a 100C rate and survive!

A 4S pack can jump start a car 20 times in 20 below zero weather:
http://www.youtube.com/watch?v=qcvmvrmTMMk

I have a 4S2P pack in my 15,000 lumen light. That light has a jumper cable connector…

A123 also makes some larger format batteries, including an awesome 20Ah pouch cell. Those provide the backup power (dual redundant 16S packs) in a 180,000 lumen light that I designed.

That Youtube vid was awesome!

HKJ
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texaspyro wrote:
Actually, these batteries can be awesome in a direct drive light. They spend 90% of their charge between 3.1 and 3.3V... matches a 3.2 Vf LED almost perfectly.

The batteries can only hold 3.2 volt at low currents (maybe 5A) and you cannot even drive a XM-L at full power with 3.2 volt (Maybe if you can select between a couple of XM-L, you can find one with low enough Vf).

This battery can easily drive 10 XM-L leds at full power, but then they need a Vf of 3 volt and a very good connection from the battery to the leds.

texaspyro wrote:
Oh, and don't let the specs fool you. They can output over 200A into a short circuit!

Not very surprising, any battery can deliver more than their rated current when shorted.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

texaspyro
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One thing to be aware of if you want to salvage them from DeWalt tool packs is that DeWalt has stopped using them. They now build their packs out of pairs of Samsung 18650 LiFePO4 cells.

Many of the cells that I am using came out of DeWalt packs. They were sent to me by a guy that salvaged them so I could test my spot welder on them. They were all a 0V… totally dead trash, right? On a lark, I tried charging them (outside). Over half were perfectly good. These cells are very rugged and take abuse in stride (not that abusing any lithium cells is ever conducive to you having a long and happy life).

And, as usual, beware of Chinese fakes. Also, A123 never sells to anybody but high volume (<$10,000,000) certified users. There are apparently LOT of valid A123 cells that made it out the back door of the factory after being produced on the “late night, off the books, ghost shift.” The 20Ah pouch cells are apparently from their failed bid for the Chevy Volt business and the Fiskar Karma fiasco (where they made $50 million+ of suspect cells due to a wonky welding machine).

I also bought a couple of dozen cells that were made in 2006 as part of their evaluation kits. A company bought them and put them on the shelf, unopened, for 5 years. They were stored at the factory 50% charge. When I got them, I put them on my analyzer (uncharged) and they all still had 40% charge remaining… a self discharge rate of under 5% per year. They all charged just fine and had full capacity and specs.

sb56637
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Thanks very much! Frontpage’d and Sticky’d.

Budget Light Forum ...where Frugal meets with Flashlight!

cainn
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I absolutely love these batteries. I used them almost exclusively in packs that I assembled for a couple of 1/8th scale brushless monster trucks back when I was still into RC. I still have 10 bare cells laying about that I put a partial charge into occasionally, just so they will remain in good condition should I ever have a use for them again. All harvested from Dewalt packs back when they could still be found inside.

Brings back fond memories Smile

Ledsmoke
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What a serious battery! And serious testing too. Discharging at 30 amps? Wicked! You rock HKJ!

~ Ledsmoke ~

Dutch humor:

[quote=djozz]

 I do not think that the BLF-community ben