The costs of running this huge site are paid for by ads. Please consider registering and becoming a Supporting Member for an ad-free experience. Thanks, ECF team.

Bench Test Results: Kdest Orange 25A 2400mAh 18650...average 20A performer, Kdest is changing wrap

Discussion in 'Batteries and Chargers' started by Mooch, Dec 11, 2019.

Thread Status:
Not open for further replies.
Image has been removed.
URL has been removed.
Email address has been removed.
Media has been removed.
  1. Mooch

    Mooch Electron Wrangler Verified Member ECF Veteran

    Supporting member
    May 13, 2015
    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, Murata, LG, Panasonic, Molicel, 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 physically and electrically protected battery pack. Never exceed the battery’s current rating and keep the plastic wrap and top insulating ring in perfect condition. Use of any of these batteries is AT YOUR OWN RISK.

    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.

    F6ACB09B-6CFD-4CB7-A7F2-E0430E7BA691.jpeg CD7DECB4-F383-42DF-95B1-E61447E5D417.jpeg E925FEA2-E00C-4287-8FB8-8596E45CF59A.jpeg E9B1F690-35E5-4ADD-84B5-3E1646FF54B3.jpeg 792F9C07-D0BD-4CBE-ACD3-5AC43B0B3621.jpeg


    Bottom Line
    This is an extremely popular battery in Asia, especially the Philippines. It is an average performing 18650 cell that has a slightly exaggerated current rating. The Samsung 25R performs a bit better and the Sony/Murata VTC5A performs much better than this Kdest. Its very high internal resistance means it suffers from a lot of voltage sag, very badly affecting its performance.

    The capacities for the four Kdest Orange cells I tested ranged from 2613mAh to 2676mAh at 480mA (0.2C) down to 2.5V. This isn’t great consistency but it is significantly above its 2400mAh rating and this inconsistency is typical of cells not from the major manufacturers. I am rating it the same as Kdest did, 2400mAh, to prevent confusion.

    I also tested two of these cells that I purchased from a Philippines shop owner (visiting New York City) that were slightly different in appearance and that had a lower capacity but they were still a bit over the 2400mAh claimed rating. Kdest says that was an older batch and all the cells shipping now are the ones I tested at 2600mAh or higher. You won’t notice any difference between these cells unless you are going down below about 3.0V though so you are not using “bad” cells if you have the older 2400mAh ones. It’s not worth replacing your 2400mAh ones with the newer 2600mAh ones either. You won’t notice any performance change.

    I hope that any future changes in Kdest cells also have a change in the wraps to let us know which cells are which. If a cell I have tested is ever changed without a wrap update then that cell will receive a Do Not Buy recommendation.

    This Kdest cell reaches about 94°C when run at its claimed rating of 25A. This is much too hot to be rated that high. After only ten cycles at 25A there was a noticeable drop in performance. The amount of voltage sag at 25A is huge too. I am rating this cell at 20A continuous.

    The 50A “max” rating is useless. When discharged at that level the voltage instantly dropped to about 2.9V. In addition, Kdest does not specify what was used to set the “max” rating so we can’t use it to compare this cell to any others. This cannot be called a 50A battery just because it doesn’t instantly explode at 50A.

    I am VERY happy though that after discussing my test results with Kdest that they are going to be updating the wraps! They said they will be lowering the continuous current rating (CDR) to 20A and removing the 50A “max” rating from the wrap. This is great news. I don’t know when this will happen but will I post as soon as I get that information.

    Kdest sent me the datasheet and MSDS (this cell is listed as being NMC chemistry) but I will not receive the UN38.3 safety test report for three weeks or so. If I do not receive it within one month, by January 10, 2020, then this cell will be given a Do Not Buy recommendation.

    Why am I not slamming Kdest now with a Do Not Buy recommendation for the missing safety document? I’m not trying to hurt companies that don’t have the safety documents. I am trying to get them to change how they set ratings and to have them get the documents for every cell before anyone tests them. This might mean giving a company a little bit of slack if they have some documents but not others. If they don’t follow through on their promises though then I will definitely give the cell(s) a Do Not Buy recommendation!

    Having no documents, ignoring my requests for documents, or having documents with obviously faked information leads to an instant Do Not Buy recommendation though.

    Kdest (www.kdest.com) donated four cells for testing, thank you!


    Continuous Current Discharge Graphs
    F95E090F-DD7D-4ACF-802D-52F181280831.jpeg 790FB98C-7326-48F4-BFAB-0739F1FD9064.jpeg 8C765039-E000-4873-8AE7-784E524B6869.jpeg


    Ratings Graphic
    75E86789-4267-45DE-BE60-F6B9901113C5.jpeg


    Performance Specs
    • DC Internal Resistance = 24.5mOhms*** (milliohms) average for the four cells.
    • Watt-hours (energy) delivered at 10A down to 3.2V = 6.4Wh
    • Watt-hours (energy) delivered at 20A down to 3.2V = 4.1Wh
    Kdest paid a fee for rush testing of these newer cells. I already had cells to test (which I do for free) but they said they did not want to wait the 2-3 months for their newer cells to make it through the testing queue so they paid a fee to be moved to the front of the line. Kdest wanted everyone to know what they were shipping to the distributors now. Receiving a fee can’t possibly affect my test results as this is not a review, this is science with hard data. Anyone can duplicate my testing and I am always happy to help them do so.

    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, battery and charger testing and 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.

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

    ***I have switched test jigs, resulting in slightly lower IR readings versus my previous setup. Add 1.6mOhms to this IR value in order to compare these cells to others tested previously.
     
    • Like Like x 1
    • Winner Winner x 1
  2. sonicbomb

    sonicbomb Vaping Master Verified Member ECF Veteran

    Feb 17, 2015
    1187 Hundertwasser
    Cheers Mooch
     
    • Like Like x 1
Thread Status:
Not open for further replies.

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice