Bench Test Results: Aspire 40A 4000mAh 21700...hugely overrated, incorrect Aspire data, rewrapping

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Mooch

Electron Wrangler
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  • May 13, 2015
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    These tests below only note the estimated ratings for these batteries at the time I tested them. Any battery that is not a genuine Samsung, Sony, LG, Panasonic, or Sanyo can change at any time! This is one of the hazards of using “rewrapped” or batteries from other manufacturers so carefully research any battery you are considering using before purchasing.

    Misusing or mishandling lithium-ion batteries can pose a SERIOUS RISK of personal injury or property damage. They are not meant to be used outside of a protected battery pack. Never exceed the battery’s current rating and keep the plastic wrap and top insulating ring in perfect condition.

    Testing batteries at their limits is dangerous and should never, ever, be attempted by anyone who has not thoroughly studied the dangers involved, understands the risks, has the proper equipment, and takes all appropriate safety precautions.

    If the battery has only one current rating number, or if it only says "max", then I have to assume the battery is rated at that current level for any type of discharge, including continuous.

    A80378B3-60F0-4619-88B3-66CC7C5506C9.jpeg B48E00DD-62DA-406E-B7B5-0C4DB8A2E792.jpeg F21AC514-5736-42FD-8BB3-504AD8B298F1.jpeg CF515B64-3C03-4AF7-8E30-B235BB0A7921.jpeg


    Bottom Line
    Along with Aspire’s new 3000mAh 18650 this one also made me angry but they are willing to rewrap this cell too. Aspire has a good reputation so my expectations were high. But for this cell they decided to roll us back a couple years and use an exaggerated current rating without even an indication it is some sort of “pulse” rating.

    The wrap on this cell just says “40A”. We can only assume, since there is no (useless) “max” or pulse” designation, that this means this cell is rated to 40A even for a continuous discharge. But the two cells I tested at that level both failed about halfway through the discharge, tripping an internal protection device which renders it useless.

    While it’s great that these cells protected themselves the fact that they could not even complete one discharge at the rating on the wrap was disappointing to say the least.

    Some other concerns...

    A paper insert included with the cell seems to indicate that they are claiming this cell has a continuous rating of 30A. A “Vaping Simulation” rating of 40A is also given by them on the insert. What happens if this paper insert is lost or cells are taken out of their boxes for display in a shop? There would be no indication as to how exaggerated the 40A number on the wrap was.

    The discharge graph for this cell, formerly on the Aspire web site, shows some temperatures close to what I measured but the legend at the top has the temperatures mixed up.

    Additionally, the temperature for the 20A discharge on Aspire’s discharge graph, 62.2°C, doesn’t match the temperature on their paper insert, 58°C.

    The four cells I tested delivered 3839mAh, 3953mAh, 3991mAh, and 4112mAh at 0.8A (0.2C) down to 2.5V. Only one of the four met its 4000mAh rating and there was a large range of values. Every cell should easily beat the capacity spec as it’s just a minimum guaranteed value. It should not be the maximum you can expect if you’re lucky.

    Their performance varied from cell to cell much more than is typical for cells from Samsung, Sony, etc., but this is an issue with most of the China-manufactured cells being sold to vapers.

    The four cells ran too hot at 30A, 83°C-87°C, for that to be their rating. I am estimating this Aspire’s ratings to be 25A and 3800mAh.

    Immediately after testing I fired off an email to Aspire basically yelling at them for all the things mentioned above. We spent a lot of time talking and I agreed to include a statement from them in this test report. I’m happy to say that they are willing to take the unsold stock of this battery and rewrap them all with more accurate ratings.

    Four cells were donated for the purposes of testing by Aspire (Aspire® Official Site - Best E Cigarette, Vape, Tank, Mod). Thank you!


    Aspire’s Statement
    B9896766-048E-46B4-A999-CA23E01D34FF.png


    Continuous Current Discharge Graphs
    3A83C1B6-8D92-4CE2-B11C-A9A23BA17515.jpeg 6AF6D005-E052-4552-B9B7-B248AB518550.jpeg


    Aspire’s Insert and Discharge Graph
    B4CDBF15-30B6-4451-AF19-711BEDF9B650.jpeg 8611EB9D-5441-4A9B-A3D6-E16FA3931A40.png


    Ratings Graphic
    B4DBC121-7614-42BC-96B4-6A6F0A246168.jpeg


    Performance Specs
    - DC Internal Resistance = 16.3mOhms (milliohms) average for the two cells.
    - Total energy delivered down to 3.2V at 10A continuous = 7.9Wh (Watt-hours) average
    - Total energy delivered down to 3.2V at 20A continuous = 4.8Wh (Watt-hours) average

    I want to work for the vaping community full time! If you feel what I do is worth a couple dollars a month and you would like early access to battery availability and testing news and a say in what I test then please consider becoming a patron and supporting my testing efforts: Battery Mooch is creating battery tests and educating vapers | Patreon.

    Aspire paid a fee to be moved to the front of the testing queue, which currently has a 10-12 week backlog. This cannot influence my test results as they pay in advance, have no say about what is in this report, and I don’t care if any company never does this or donates batteries again. My reputation is a lot more important than any battery donation or payment.

    To see how other cells have tested check out this link: List of Battery Tests | E-Cigarette Forum
     

    Ballti

    New Member
    Oct 17, 2018
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    Im using 8 x Aspire 21700 4000mAh for e-bike, looks like was a better "battery patch", all 8 new batteryes was on 3.84V, same charged capactity to 4.2V. After ~20 full charge, pack have 3705 mAh form 3V to 4.2V, cutoff charge C/20 200mA, discharge C/40 100mA. At lower voltage 0.1V = ~100mAh, so whit starting 2.7V, charge is ~4000mAh.
    Load is low, 5A-12.5A 8-10 minuts 2x, then charge.
     
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