How I test lithium cell and power bank capacity.

แชร์
ฝัง
  • เผยแพร่เมื่อ 16 ม.ค. 2025

ความคิดเห็น • 526

  • @bendibell
    @bendibell 6 ปีที่แล้ว +112

    I test them by putting them in the microwave. The ones with the largest explosions and most poisonous gas are the ones with the highest capacity. The extra high quality ones have fumes that make me cry blood.

    • @gordslater
      @gordslater 6 ปีที่แล้ว +4

      if it ain't gonna kill you it ain't worth doing - that's my rule for life

    • @gyrgrls
      @gyrgrls ปีที่แล้ว

      I once used a saline solution to test one. It was taken as a salt and battery, and I faced a few charges. 😂

    • @gyrgrls
      @gyrgrls ปีที่แล้ว +1

      ​@@gordslaterYa gotta use a FULL WAVE BRIDGE RECTIFIER! 😅

  • @twocvbloke
    @twocvbloke 6 ปีที่แล้ว +35

    It's nice seeing videos like this that respond to the "internet experts" who claim things, but have no practical experience of what they're talking about... :)

  • @TheHWcave
    @TheHWcave 6 ปีที่แล้ว +22

    The Ruideng UM34 USB tester is very accurate but it has a few quirks you need to be aware of. It is definitely a good idea to turn the display off (or very dim) because it eats a lot of power and if testing at higher than 5V, the internal voltage regulator in the tester gets very hot. Another problem is that the lowest measurable voltage is just 3.94V, because below that the unit turns off. The capacity recording threshold mentioned by Clive has bugs too and can produce wrong capacity readings. There are a full reviews of the UM34 and the UNI-T tester on my channel if you want more details.
    The reason why you always measure less capacity (mAh) going out of a USB power bank than in is partly due to the losses in the step-up converter as Clive mentioned but mostly because of maths. For example, a Li cell producing 1A for 1hour at (average) 3.6V has a capacity of 1000mAh and delivered an energy of 1A*3.6V*1h = 3.6Wh. These 3.6Wh get converted to the same energy on the USB side but 3.6Wh on 5V means the current is only 0.72A for 1h (ignoring losses in the converter). So the capacity measured on the USB side is only 720mAh and in reality, even less if the conversion losses are factored in.

    • @stalwartcomputers5182
      @stalwartcomputers5182 6 ปีที่แล้ว

      I thought it was 3.64v before they cut out but it MIGHT just be because the ones we have had made with/by R&D are slightly tighter tolerance/rated components not just a cheap mass production run type 20-40% rated component used.

    • @amigaman9433
      @amigaman9433 6 ปีที่แล้ว +1

      thats a very interesting review, bit over my head but very interesting but one thing I don't get is why this device measures an input voltage up to 24v, isn't USB 5v

    • @TheHWcave
      @TheHWcave 6 ปีที่แล้ว +2

      @@amigaman9433 5V is the default but even back in 2012, devices could negotiate a higher voltage and current if both the device (e.g. phone) and the charger / power bank agreed with each other. Voltages were initially 5V, 12V and 20V and USB2.0 added 9V. There are also different currents that are negotiated and the way how these negotiation protocols work and have evolved over the years is quite complicated. The UM34 by the way recognises some of the older protocols and lists them on the screen if it detects that they are being used. It doesn't understand the more modern ones but that is no problem as it will always show whatever voltage and current has been agreed even if it doesn't understand the used protocol.

    • @PunakiviAddikti
      @PunakiviAddikti 6 ปีที่แล้ว

      Well the low voltage doesn't really matter because you'll be using this thing for USB anyways. If you want to measure non-USB things you'd get a professional power logger.

  • @ahaveland
    @ahaveland 6 ปีที่แล้ว +14

    Clive, in the DIY Powerwall/second life hobby world, we use the Opus BT3100 to test capacities discharging at 1 amp. This helps to standardize results. It tests 4 at once and does the charging, discharge measurement and recharge and then we just write the mAh value on the cell. Can speed things up a lot by pre- and post-charging with a rack of TP4056s or other chargers. With 10 Opuses we can test around 200 cells per day. Those that get hot during 1A charge are rejected as well as those that get excessively hot during discharge. (A good cell should never get hot during a 1A charge, but is ok to get a little warm on discharge).
    Then let stand for a week or two and measure voltage again - any that have self-discharged less than about 4.10V should also be rejected and go for recycling.
    Using this method I have over 1000 good cells after testing over 3000 cells and always looking for more to do!

    • @bigclivedotcom
      @bigclivedotcom  6 ปีที่แล้ว +4

      I have noticed a pleasing quirk in human nature that makes us harvest lights, solar panels and power storage devices. Is your power wall vented to outside in case of any incidents?

    • @amigaman9433
      @amigaman9433 6 ปีที่แล้ว

      this is pretty much the way I check my salvaged Li cells, charge to 4.2 discharge to 3.0 then charge to 4.2 that will give me a ballpark figure of the mAh, leave for 2-3 weeks any that are 4.0v or lower are discarded (sold on ebay)
      it helps to have the datasheet as most power tool battery packs contain low mAh but high discharge generally 20A or higher where as most laptop packs are high mAh low discharge.
      I've been using my old SkyRC iMAX B6AC V2 but at 1 cell at a time I'm tempted to splurge on the SkyRc MC3000... might need to get a Patreon account tho lol

    • @ahaveland
      @ahaveland 6 ปีที่แล้ว +1

      @@bigclivedotcom Powerwall still under construction but I will use it for an ebike with a trailer for extra range, so won't be used indoors except for power outages. Have had no incidents since working with cells over the last 2 years - except for cuts and bruises while spudging laptop packs!
      It takes a lot of time to evaluate each cell and enter into a database for tracking histories, and for sizing allocation to make equally-sized cellpacks.
      Yes, safety is an important consideration - if and when I do make a permanent powerwall then it would be surrounded by paving slabs or live outside. Not practical at the moment in a 3rd floor flat.
      I made four 120W portable solar panels using 6 A3 sheets of foamboard that weigh just over 1kg each and all fit in a backpack so I can ride hundreds of miles for free.
      First I made a 2kWh 14S16P ebike battery 18 months ago and that works really well. I'm still in the process of building a 7kWh battery out of the remaining 800 cells to go in a trailer.
      Now I make a portable solar tracker using 3D printed worm drives, steppers, arduino and a gps module and that's taking my time right now. The gps module allows me to calculate the elevation and azimuth of the sun anywhere in the world and I'm hoping to be able to mount the 480W of panels on it and all for a really minimal cost.

    • @ahaveland
      @ahaveland 6 ปีที่แล้ว

      @@amigaman9433 Get an Opus or 2 or 3... follow HBPowerwall, jehugarcia, Average Joe, DIY Tech & Repairs, Vortecks, Andy Kirby - and you'll also learn a lot from them.
      (This is my list of movers and shakers in the 18650 world)

    • @stepheneyles2198
      @stepheneyles2198 6 ปีที่แล้ว

      @@ahaveland Have you made an Instructable about those 120W solar panels? I'd like to see whether I could make one myself... Although I can't quite see how 6 sheets of A3 foamboard fit into a backpack... :-/

  • @kingearwig
    @kingearwig 6 ปีที่แล้ว +87

    The complexity of this video exemplifies the reason we should be measuring cell capacity in watt hours.

    • @SubjektDelta
      @SubjektDelta 6 ปีที่แล้ว +14

      nah mAh

    • @davey2k12
      @davey2k12 6 ปีที่แล้ว +5

      Bit much for batteries watt hours 😂😂😂ffs unless ya made a big pack and running something that lasts days then yeh but single cell pointless stay with mAh or Ah

    • @AsphaltAntelope
      @AsphaltAntelope 6 ปีที่แล้ว +5

      For non techy, non electrical people like me, who just enjoy Big Clive's soothing voice, watt hours would be good ESPECIALLY since that's what electric car batteries are measured in. I don't really know the difference between a watt and an amp, I definitely don't know how to convert between the two. As electric cars become more popular and people get used to car battery capacities, charging rates, cost of electricity per kWh etc.... you get my point.

    • @clausjellinggaard756
      @clausjellinggaard756 6 ปีที่แล้ว +11

      @@themonkeydrunken Typo. The rule of thump is actually: Watts = Amps * Volts. Amps = Watts / Volts. ( P = U * I).
      And it's probably a good idea to always include some kind of disclaimer about AC, where VA is not the same as W because it's complicated by capacitance/impedance/etc unlike DC.

    • @davey2k12
      @davey2k12 6 ปีที่แล้ว

      @@AsphaltAntelope FFS bro ya best for get it if ya think like that .......start small then go big or ya got a death wish .......the size of the packs or cells in EVs eg there's like over 5000 18650s in there ....but all it does is make the number smaller for dumb people 😂😂😂 cus of lack of brain cells 😂😂😂😂 and there's no difference between watt and amps .......... amps and volts is energy applied to the circuit...... the watt is a measure of used or wasted energy ....if ya wanna go basic lol

  • @AnthonyGoodley
    @AnthonyGoodley 6 ปีที่แล้ว +21

    Thanks for such an educational video. Links to the products you recommend would be very useful and could make you a bit of money too!

  • @Alan_Stinchcombe
    @Alan_Stinchcombe 6 ปีที่แล้ว +1

    Thanks for this, Clive. Having RTFMed the instructions with the UNI-T UT658, I got sucked into measuring the charge delivered by a powerbank. However, your video made me realise that the powerbank's boost converter will draw some of the cell's stored charge to boost the voltage to 5V so, inevitably, it delivers less charge to the load.
    As you point out, the only fair test of a cell's capacity is to measure the charge that a charger delivers to it through a powerbank's dropper-type charging circuit. I think you later discovered that even the upmarket Duracell PB2 powerbank doesn't have a buck converter that would draw less charge from the charger than it delivers to the cell.

  • @michaelditto
    @michaelditto 6 ปีที่แล้ว +17

    Happy New Year, Clive, lovely video as always.
    I'd like to embellish your statement @13:30, that you wouldn't get 3Ah out of the power bank containing a 3Ah lipo cell because of the step-up conversion losses. It's not because of the conversion losses as much as it is the voltage difference. With an ideal lossless conversion you'd pull, say, average 3.7V * 3Ah = 11.1Wh from the cell and put that same energy out at 5.0V, meaning 2.22Ah @ 5V.

    • @theR6969
      @theR6969 6 ปีที่แล้ว +4

      michaelditto , this is exactly why he always measures lower capacity than stated .. he measures mAh @ 5v then compares it to the stated capacity @3.7v and always concludes that the actual capacity is less than stated .. he tends to forget the voltage difference.

    • @Burkhardj
      @Burkhardj 6 ปีที่แล้ว +5

      That's why the unit Ah is crap.

    • @TheCubicnz
      @TheCubicnz 6 ปีที่แล้ว +5

      theR6969 if you advertise a power bank as having a certain Ah rating, I think it’s fair for the consumer to expect to be able to pull that many Ah from the device. Stating an internal current value the user of the device will never see is misleading. I do understand the manufacturers probably buy the cells by Ah and simply re-state that number in their marketing, but is that the right thing to do?

    • @Rob2
      @Rob2 6 ปีที่แล้ว +2

      I agree with you that it is not right. However, it is common practice, making it difficult for a single manufacturer to do it right, as they would have a lower Ah rating than the competitor.
      It would be much better to specify the number of Wh.

    • @Mark1024MAK
      @Mark1024MAK 6 ปีที่แล้ว +3

      Whether you use Ah or Wh (both have different advantages and disadvantages, neither tells you everything) for a capacity rating to be valid, the load resistance and end point voltage, or the load current and end point voltage, or the load power and end point voltage also need to be stated.
      In reality, use the figures as a rough guide. As the capacity will fall over time/usage anyway.
      I don’t see any drive for manufacturers/suppliers/shops to change, as (1) the fakes are skewing the market on eBay and other similar web sites and (2) to the ordinary user with little or no knowledge of electronics/electricity, the capacity whether stated in Ah or Wh is just a number where bigger is better and nothing more...

  • @paullangenberg5907
    @paullangenberg5907 6 ปีที่แล้ว

    Hi Clive
    Every time i watch one of your videos I learn something , and i realy enjoy that. Don't know a lot about electronics ,but always try to find out what or why something failed

  • @stonedsavage7814
    @stonedsavage7814 6 ปีที่แล้ว +1

    Wow clive an upload at gone 4AM? I am not going to complain one bit about this as this has made me smile thanks clive.

  • @barryfairwood2174
    @barryfairwood2174 ปีที่แล้ว

    Excellent video, thanks. I bought 3 on eBay along with 3, five volt, 6 watt solar panels. I am a big fan of 18650 lithium cells. Salvaged from discarded power banks. Always on search for disposable vape devices.

  • @alfredlangenberg5877
    @alfredlangenberg5877 6 ปีที่แล้ว +1

    Hi Bigclivedotcom big fan of your videos whenever I come back from work I always put one of your videos on and it's fun to watch you take something apart and find out what's inside and you do a great job of explaining everything, I think a good video for you in the future would be taking apart a laptop's battery and explaining how you could repurpose the cells and explaining how the charge controller works

  • @Darieee
    @Darieee 6 ปีที่แล้ว +3

    6:20 ooowyhea, can’t wait to see that opened up
    I’m pretty sure the anker power banks also have switching dc-dc converters for charging ... at 12W in from 5v ... no way they can stay luke warm over the entire charge cycle

  • @quakerz1228
    @quakerz1228 6 ปีที่แล้ว +1

    Thanks for the informative video! ended up getting myself a Uni-T meter after this to test various batteries around the house now

  • @gladiusilluminatus3720
    @gladiusilluminatus3720 6 ปีที่แล้ว +52

    Holy cow I think this was the longest: "I run em flat and charge em up again" I have ever heard.
    But verry intresting and entertaining nontheless keep it up.

    • @dodge911
      @dodge911 6 ปีที่แล้ว +6

      Yeah, but it's the way you run 'em flat and charge 'em up again...
      I've got videos on the whole charging/discharing cycle for all available outputs for the powerbanks I test :)

    • @thany3
      @thany3 6 ปีที่แล้ว +3

      And then run em flat again, because you also want to know the difference between how much goes in and how much comes out ;)

    • @BPantherPink
      @BPantherPink 6 ปีที่แล้ว

      @@thany3
      In my case... 8 inches goes in and 4 inches comes out ‼️😂😂

    • @JuanHerrero
      @JuanHerrero 6 ปีที่แล้ว

      The devil is in the details.

    • @Solocat1
      @Solocat1 6 ปีที่แล้ว

      if that's all you got out of that video than it went over your head.

  • @TheHoofn
    @TheHoofn 6 ปีที่แล้ว

    You have quite a few tools that are more convenient than the sort in my engineering group. I would be in heaven seeing your workshop up close.

  • @cbm80amiga
    @cbm80amiga 6 ปีที่แล้ว +1

    Clive, easiest way to check charged/discharged capacity of 18650 or similar cells is just to use dedicated charger like LiitoKala Lii500 or cheap IMAX B6 for almost all kinds of chemistry.

    • @bigclivedotcom
      @bigclivedotcom  6 ปีที่แล้ว +1

      I use this technique to test cells sealed inside equipment.

  • @jlucasound
    @jlucasound 6 ปีที่แล้ว

    You are so good Clive. Love the soothing Scot accent.

  • @MrFlint51
    @MrFlint51 6 ปีที่แล้ว

    Hi Clive
    On your New Year's Eve live stream you mentioned you old dentist. David is actually my oldest friend from school days. We used to play in bands together, him on lead guitar and me on organ.
    We used to make fuzz boxes and wah-wah pedals , sound activated light boxes and all sorts of gadgetry.

  • @Petertronic
    @Petertronic 6 ปีที่แล้ว +1

    Great video - but you didn't show any of your test loads. I have a resistive one and also the electronic one, with the heatsink with the tiny fan on it, and I get different results with each. mAh doesn't take voltage into account so I always convert to Watt-hours.

  • @daShare
    @daShare 6 ปีที่แล้ว +21

    I guess Watt hours (Wh) would be more accurate when comparing the bare cell to the 5V bank output ?

    • @boggisthecat
      @boggisthecat 6 ปีที่แล้ว +2

      da-Share
      Yes, it would. As an example, what Clive started near the end could confuse people: a 3.7 V cell capable of outputting 1 A for three hours is absolutely not going to be able to output that same 3 Ah at 5 V. Shifting the discussion to the energy capacity in Wh would make this far easier to understand.
      (Photography review websites always use the Wh ratings, for example, as this lets the reader know how much energy is available in a given cell or battery - and this is what people really want to know.)

    • @gordonrichardson2972
      @gordonrichardson2972 6 ปีที่แล้ว +1

      da-Share LOL, at 13:15 Clive says Watt else...

    • @ethanpoole3443
      @ethanpoole3443 6 ปีที่แล้ว +4

      da-Share Not really as W-hr is skewed by the linear regulator during charging and you will need to compensate for the 85-90% efficiency of the 5V boost switching regulator circuit during discharge and both of those will require compensation to determine actual battery capacity (though either would be an acceptable measure of actual powerbank capacity as a complete unit). Since nearly all of these powerbanks use a linear regulator charge circuit the easiest figure to work with is the mA-hr capacity input to the battery during charging (from fully depleted cutoff voltage) then if you want an estimate of W-hr capacity multiply the mA-hr figure by the nominal 3.6-3.7V of the Li-ion cell to get the battery’s native capacity. Since you will get better than 99% of what you put into a Li-ion battery back out of the battery the discrepancy between input and output power is less than 1%, hence it is easiest to work with the mA-hr figure you put into charging the dead battery to figure actual capacity if the internal battery.

    • @Mark1024MAK
      @Mark1024MAK 6 ปีที่แล้ว +5

      There are advantages and disadvantages when using Wh, the same as there are advantages and disadvantages when using Ah.
      If there are no buck or boost converters, Ah is a more useful unit to use.
      If there are buck or boost converters, Wh may be a more useful unit to use.
      It all comes down to what and where you are measuring, or what the load is on the cell/battery.
      For example, if using a high capacity lead acid 12V battery that is directly supplying a 12V load, as no conversion circuitry is involved, Ah is the more useful unit, as that tells you how long the load will run for at a near constant current.
      All cell/battery manufacturers use Ah to state capacity (including primary and secondary cell types).

    • @Rob2
      @Rob2 6 ปีที่แล้ว

      Can you explain what are the disadvantages of using Wh?
      I am not aware of any. There only are advantages.
      (except when you want to count "impossibility to confuse the customer" as a disadvantage, of course)

  • @dashcamandy2242
    @dashcamandy2242 6 ปีที่แล้ว +1

    You're right about the blue power bank. I have the exact same one (sold under the Vivitar brand), two no-name 18650s wired parallel. Ridiculously SLOW charge. It does, however, work quite well.

  • @whitney3383
    @whitney3383 6 ปีที่แล้ว

    Good job Clive. Keep up the good work. Love your channel dude!

  • @kuhrd
    @kuhrd 6 ปีที่แล้ว +2

    When at all possible I generally try to gain access to the bare cell(s) in the power bank and cycle them 3-5 times on a reasonable quality hoppy charger that has been calibrated against my HP 6.5 digit bench meter. I would say your method is far easier for most people and you can test the entire power bank with the limits it has been factory programmed with.

  • @avejst
    @avejst 6 ปีที่แล้ว +41

    Nice roundup on Lipo batteries
    Thanks for sharing👍😀

    • @The1wsx10
      @The1wsx10 6 ปีที่แล้ว +8

      (not a lipo)

    • @whitehoose
      @whitehoose 6 ปีที่แล้ว +1

      Lithium-polimer/ion - slightly different electrolyte chemistries alloy doping and nominal voltages but the same pixies drive them. The value is it's the same principles that can be applied to any battery to measure it's capacity, even if not rechargeable.

  • @theR6969
    @theR6969 6 ปีที่แล้ว +11

    Now a days respectable battery makers list the power in Watthour instead of mAh .. it gives more accurate indication of how much power the battery can store .. every time you test a battery capacity you state that it took "x" mAh which is less than the capacity listed .. yet you seem to forget that you're measuring the mAh @ 5V .. while the rated battery capacity is listed @3.7V .. that's how you always end up with lower mAh "nominal" capacity while the true Wh measured capacity is actually higher. example: that Duracell power pack, it listed the capacity of 6.7 Ah @ 3.7v .. your test measured 5.4 @5v .. but 6.7x3.7= 24.79 Wh, while 5.4x5= 27 Wh. which makes sense .. it's the battery capacity + all the losses in the circuits .. thus their listing if capacity as 6.7ah is true.

    • @Mark1024MAK
      @Mark1024MAK 6 ปีที่แล้ว

      theR6969 - there are also disadvantages with the Wh unit... Wh is less useful if you want to use a cell or battery to directly supply a load that requires a constant voltage and you want to know how long such a load will run for.

    • @IrishSkruffles
      @IrishSkruffles 6 ปีที่แล้ว +3

      If the Duracell power bank has a switching charger then what you said is true, but most power banks use linear charging ICs. With linear charger IC's the mAh rating is correct regardless of the charge voltage since the current is the same throughout the circuit - it acts as a resistor.

    • @theR6969
      @theR6969 6 ปีที่แล้ว

      Mark 1024MAK ,I understand .. my point was referring to Clive always coming up with less capacity than listed .. he's always measuring input capacity @5v while batteries stated capacity is always at the battery's nominal voltage.

    • @theR6969
      @theR6969 6 ปีที่แล้ว +2

      Skruffles , no matter what type of circuits are used .. there's always losses and efficiency. my point is, he's expressing capacity the wrong way .. capacity in mAh changes with voltage.

    • @vink6163
      @vink6163 6 ปีที่แล้ว

      @theR6969 but the battery banks are rated at 5 V, so their Ah rating should match when measuring at 5 V...

  • @SCP-POOL
    @SCP-POOL 6 ปีที่แล้ว

    Happy New Year Clive! Please have a safe, enjoyable & extremely prosperous 2019!

  • @amorphuc
    @amorphuc 6 ปีที่แล้ว

    Thanks Big Clive. I love your reviews and Happy New Year to you!

  • @maxximumb
    @maxximumb 6 ปีที่แล้ว

    Interesting video Clive. Thanks for answering questions I never knew I wanted the answer to but am glad I now know.
    Happy new year.

  • @ceneblock
    @ceneblock 6 ปีที่แล้ว

    I'm very curious about the clock you made and had shown for testing.

  • @notyoung
    @notyoung 6 ปีที่แล้ว

    For the 18650 (and similar) cells, I like the BT-C3100 NiCd/NiMH/Li charger/discharger. For the wired cells, I use a dummy 18650 cell with solder tabs to connect the cell under test to the BT-C3100. The charge and discharge currents are settable and the unit can be set to the repeated charge/discharge mode - excellent for getting a new cell to its maximum capacity.
    Seeing the fireworks - and the Fire Department's question about live ammo - from Rick's Disney car fire, I'm glad I opted for older technology (lead-acid AGM batteries) for my small solar system. The 82AH (8 hour) or 90AH (20 hour)12HX330FR batteries are very capable, being rated to deliver 586 amps for 2 minutes and 3700 amps short circuit current, but the voltage tolerances aren't nearly so stringent as the lithium cells. If the charge voltage gets a little above the float voltage of 13.65, it's not a problem as DataSafe recommends occasional charging to 14.4 volts in what would be an equalization cycle for a flooded battery - but only 4 or 5 times a year. For a 6 battery, 540AH battery bank in the basement, I'd much rather have the larger AGM batteries.

  • @knucklecorn
    @knucklecorn 6 ปีที่แล้ว +1

    I don't like any of the displays on those USB-testers. What happened to the nice blue Keweisi branded one with an OLED?

    • @bigclivedotcom
      @bigclivedotcom  6 ปีที่แล้ว

      The new Ruiden one is a lot clearer to read.

    • @knucklecorn
      @knucklecorn 6 ปีที่แล้ว

      @@bigclivedotcom that may be but the LCD display of the UNI-T is just awful.

  • @matakaw4287
    @matakaw4287 6 ปีที่แล้ว

    Another great video. After I saw you using the mini Uni-T clamp meter I had to get one. Now I want the Uni-T usb tester. *waits patiently for the Duracell bank to be taken to bits.

    • @dodge911
      @dodge911 6 ปีที่แล้ว +1

      There are many better UPM's available than that.
      I've reviewed several of them on my channel.

  • @Alasdair-Morrison
    @Alasdair-Morrison 6 ปีที่แล้ว

    G'Day B'Clive 👍­
    ­
    Great to see you back in the new year!

  • @LiLi-or2gm
    @LiLi-or2gm 6 ปีที่แล้ว

    Great timing! I just got a Ruidang USB volt-amp meter this last weekend! Happy New Year, Clive! : )

  • @kjur18
    @kjur18 6 ปีที่แล้ว +1

    For testing normal li-ion cells analysing chargers are better, for example opus 3000 or liitokala li-500. They are quite accurate in measuring capacity, and can measure capacity when charging and when discharging. For switch mode power banks I think it's better to measure not Ah, but Wh, as Ah is voltage dependent. You put in 1A for one hour at 5V, you get 5Wh in charging circuit. Almost the same ammount of energy is then put in battery but with lower voltage/higher current, but total power put inside the cell will be around the same amount (with some loses in charger, around 5-10% is a safe bet for losses). If there is no Wh written on power bank, you can calculate this by multiplying Ah by 3,7V

  • @mikecowen6507
    @mikecowen6507 6 ปีที่แล้ว +2

    Bigclivedotcom Clive, can I get the make, model, and supplier of your yellow USB meter, please? Thanks!

    • @alphatexltd7040
      @alphatexltd7040 6 ปีที่แล้ว

      m.banggood.com/RUIDENG-UM34-UM34C-For-APP-USB-3_0-Type-C-DC-Voltmeter-Ammeter-Voltage-Current-Meter-Tester-p-1297185.html?gmcCountry=US¤cy=USD&cur_warehouse=CN&createTmp=1&ID=511646&gclid=EAIaIQobChMIvKCqs7DO3wIVAgNpCh09LAAgEAQYAiABEgIdRvD_BwE

    • @mikecowen6507
      @mikecowen6507 6 ปีที่แล้ว

      @@alphatexltd7040 Thank you!

    • @anthonytrepess4441
      @anthonytrepess4441 6 ปีที่แล้ว

      @@alphatexltd7040 Thgank you, Happy New Year

  • @TDOBrandano
    @TDOBrandano 6 ปีที่แล้ว +2

    Lithium is actually pretty safe, and an essential food supplement. It's Nickel and Cadmium that are a bigger environmental concern.

  • @superdau
    @superdau 6 ปีที่แล้ว +1

    Have you done comparisons between the mAh/Wh going into and coming out of power bank? Like measure while charging and then use a load with similar current and measure while discharging. I would be interested to know the ball park "roundtrip" efficiency of a power bank (maybe comparing the resistive and switching ones or name brand vs. chinese).

  • @nickbird7742
    @nickbird7742 6 ปีที่แล้ว

    Thanks Clive nicely explained, was your new year resolution less leds as I only saw two, yes two. Happy New year mate.

  • @ilaril
    @ilaril 6 ปีที่แล้ว +5

    What was the name of the logger you use? I'd like to get one also.

    • @ucitymetalhead
      @ucitymetalhead 6 ปีที่แล้ว +4

      I found it on Banggood www.banggood.com/RUIDENG-UM34-UM34C-For-APP-USB-3_0-Type-C-DC-Voltmeter-Ammeter-Voltage-Current-Meter-Tester-p-1297185.html?akmClientCountry=America&gmcCountry=US¤cy=USD&cur_warehouse=CN&createTmp=1&ID=511646&gclid=Cj0KCQiAvKzhBRC1ARIsANEXdgxyNLsqDInqT9NZiaHVsQgpcV1dTgIIu9bXjASuAHwyRrxWG5FVqskaAnV5EALw_wcB

    • @lostjohnny9000
      @lostjohnny9000 6 ปีที่แล้ว +2

      @@ucitymetalhead There's two versions of these meters. Only difference is on the side port where you'll either find a micro USB or USB-C socket. They are both connected "V-in" for connecting direct to wall charger cables. My green one is a micro USB.

    • @stalwartcomputers5182
      @stalwartcomputers5182 6 ปีที่แล้ว +1

      @lost jonny there is 3/4types atm not just 2,

    • @ucitymetalhead
      @ucitymetalhead 6 ปีที่แล้ว +1

      @@lostjohnny9000 good to know might have to go with the green one.

    • @lostjohnny9000
      @lostjohnny9000 6 ปีที่แล้ว

      @ucity metalhead @Stalwart Computers Both Ruidengs have a bluetooth option with a nice app for PC/Android. Maybe worth the 4 dollars extra as the little SMD side switches can break easily. Just noticed the yellow one might have both micro USB an USB-C but BG are still selling green one for less.

  • @shlibbermacshlibber4106
    @shlibbermacshlibber4106 6 ปีที่แล้ว

    You sir are a national treasure 🙏

  • @Undxkl2m
    @Undxkl2m 6 ปีที่แล้ว

    I have a cheap USB power bank (soshine E4S) that I got from ebay that has spring loaded contacts for easy replacement of 18650 cells and can measure capacity. For measuring power banks I use a device similar to what you have here, but I measure both a charge and a discharge cycle and take the geometric mean of the capacities to compensate for loses in the charging/discharging circuit.

  • @felenov
    @felenov 6 ปีที่แล้ว +1

    RuiDeng make very good digital power supply and USB tester. I have the blue one with OLED and it has a low power draw which I like. For propper testing I use my Agilent power analyzer

  • @RWBHere
    @RWBHere 6 ปีที่แล้ว

    9:35 - If you short-circuited that, it really would become a red hot chilli pepper!

  • @tornagawn
    @tornagawn 6 ปีที่แล้ว

    Just like to say your channel has been my best discovery of 2018. Long may you buy cheap trashy electronics and test them

  • @AntonioClaudioMichael
    @AntonioClaudioMichael 6 ปีที่แล้ว +22

    Can you give links Clive to all your testers or put all the names of them in the discription

    • @UD503J
      @UD503J 6 ปีที่แล้ว +3

      The Ruideng that he features (the yellow one) is also sold as the MakerHawk UM34 on Amazon, which is where I got mine. Would highly recommend. They are inexpensive and provide a lot of data. Also, other models have Bluetooth connectivity, which I have not tried.

    • @1234mattyman
      @1234mattyman 6 ปีที่แล้ว +3

      Just type in on eBay usb tester meter and they all come up

  • @matthewghali2987
    @matthewghali2987 6 ปีที่แล้ว

    Happy new year, Clive! A couple of comments- first you touch on failure modes, and how energy density is a root cause more than particular chemistry. One additional factor that I've heard that's relevant is potential for "thermal runaway"- how in some specific conditions, past a threshold the cells enter a self-sustaining reaction where their temperature increases dramatically. Some chemistries are very prone to this, while others are not at all, with only vague connection to energy density & cost, much more a function of when they were developed. Is this true?
    Also, for your testing "rig," in addition to the instruments and the pie tin, have you considered a dedicated smoke detector? They've become very small and cheap. I'd be so happy to see you include a smoke detector, especially in your overnight testing setup.
    Love the videos; thanks for taking time out to keep us entertained & educated!

  • @criggie
    @criggie 5 หลายเดือนก่อน +1

    @clive - this video is now 5 years old. Is it still how you' test a battery ?

    • @bigclivedotcom
      @bigclivedotcom  5 หลายเดือนก่อน +1

      I still use the technique, but also use a monitored discharge tester in some instances.

  • @GWorxOz
    @GWorxOz 6 หลายเดือนก่อน

    Hi Clive. That single 18650 yellow powerbank - they are designed to take the flattop 18650 cells.

  • @gregwilshaw3847
    @gregwilshaw3847 5 ปีที่แล้ว

    @bigclivedotcom would you be interested in reviewing a niche battery technology, LIPO? I'm a radio control model car enthusiast and would love to see your opinion of this batterys' performance on your test.

  • @AntonioClaudioMichael
    @AntonioClaudioMichael 6 ปีที่แล้ว +5

    Great video clive

  • @mickellis8747
    @mickellis8747 6 ปีที่แล้ว +5

    How's the hangover Clive?

    • @bigclivedotcom
      @bigclivedotcom  6 ปีที่แล้ว +5

      There was none. Bit rough, but nothing major.

    • @simonhopkins3867
      @simonhopkins3867 6 ปีที่แล้ว +1

      @@bigclivedotcom you animal ;-) lol

  • @peterlarwood8331
    @peterlarwood8331 6 ปีที่แล้ว

    Looking forward to you testing the Duracell power bank. I recently got the 10 amp one and am wondering how close to its stated capacity it will achieve.

  • @sixtyfiveford
    @sixtyfiveford 6 ปีที่แล้ว

    Can you calculate the maximum safe discharge rate ie:20, 25, 30amps of a 18650?

    • @Slicerwizard
      @Slicerwizard 6 ปีที่แล้ว

      Sure - check the datasheet.

    • @bigclivedotcom
      @bigclivedotcom  6 ปีที่แล้ว +2

      It depends on the cell. Some are optimised for high current. It's better to get them from known good sources, as many online sellers quote bogus specifications which can be dangerous with high loads.

    • @william_2610
      @william_2610 6 ปีที่แล้ว +1

      The only way is to check the datasheet. A Samsung 30Q (3Ah) is rated 15A continuous, but an unknown 3Ah cell made by some random Chinese company may only be rated for 4A continuous.

    • @andrewkieran8942
      @andrewkieran8942 6 ปีที่แล้ว +1

      This is referred to in the specs as the 'C Rating' -- the rate at which a battery can be discharged relative to its maximum capacity.

  • @Nono-hk3is
    @Nono-hk3is 6 ปีที่แล้ว

    This was going to be my question for the next Q&A session. Thank you!

  • @getcartercarpark8744
    @getcartercarpark8744 2 ปีที่แล้ว

    Hello Clive and all,
    Is it not better to know the discharge capacity of a power bank (or a Lithium cell) rather than the charge capacity?
    I ask because it is not uncommon to put more power (current/voltage/time) into a cell than you will actually get out of a cell.
    I have a power bank that when it finishes charging, the charge capacity is 2400 +/- mAh, but discharge the power bank and I only get 560 mAh.
    Charging the internal cell on its own using a lithium cell charger and then discharging the cell through a constant current load of 200 ma, confirms the cell's discharge capacity is only around 580 mAh.
    The cell is clearly of no use unless you want to put around 5 times the charge into it than you get out of it.
    However, does this not suggest that discharge capacity is more accurate than the charge capacity of a lithium cell/power bank when it comes to knowing what you can expect to get out of a lithium cell or power bank?
    Thanks,
    K Watt - yes, that is my name.

  • @Mark.D.H.
    @Mark.D.H. 6 ปีที่แล้ว

    Can you recommend an AA battery analyser? Project Farm did a great video to test the actual capacity of a few brands. He used a Powerex device but it's quite expensive at about £60.

  • @dognoseranger
    @dognoseranger 6 ปีที่แล้ว +2

    Hi Clive,
    I have an arduino cell phone device in the woods that wakes up every fifteen minutes and sends out the temperature/battery level to my server. Been using a 2500mAH lithium, which typically provides about 30 days of power before needing to be replaced. Curious if you know of a better battery option for that type of use (New England, US) or would some kind of solar cell that might be good for topping it off. It's in the woods, so mostly indirect light.

    • @bigclivedotcom
      @bigclivedotcom  6 ปีที่แล้ว +5

      If there was any chance of sunlight getting in at all then a solar panel might be able to squirt a bit more current into the cell. You could use the classic TP4056 module tacked across the battery to offer charge protection and regulate the maximum charge current. The other option is to make a dedicated battery pack with a stack of lithium cells in parallel to allow it to run for several months or a year before getting a battery pack swap.

    • @dognoseranger
      @dognoseranger 6 ปีที่แล้ว +1

      @@bigclivedotcom Thanks! My biggest concern with this project (weather conditions for mountain biking) is that a lithium cell goes rogue and starts a fire. The packs I use supposedly have over/under voltage handling, but I've watched too many youtube videos of lithiums gone bad. ":^)

    • @gd.ritter
      @gd.ritter 6 ปีที่แล้ว +1

      dognoseranger if the lithium cell you’re using has an integrated protection circuit, then it will protect against over/under voltage which would avoid most spontaneous explosion risks. Most name brand consumer cells include this these days. eBay specials and the like may not have them. Salvaged 18650s (from a power bank or laptop) often don’t have it because the protection would’ve been built into their circuit you ripped them out of.

    • @raykent3211
      @raykent3211 6 ปีที่แล้ว +1

      @@dognoseranger have you thought of making a small concrete box? By concrete here I mean just sand and cement. Probably only needs to be about 1cm thick. I've played around with using chopped glass fibre for reinforcing, but I don't think you need that. Immune to rain, freezing and moderate fire. As for battery life, is the tx being fully powered down? Is there a voltage regulator still in circuit? Maybe you've done all that already, but if not, considering the very low communication rate, you might get 2 or 3 times the life from the same battery.

    • @dognoseranger
      @dognoseranger 6 ปีที่แล้ว

      @@gd.ritter Thanks. I need to dive into 18650 info more since I didn't realize some of then had a protection circuit.

  • @chrischeltenham
    @chrischeltenham 6 ปีที่แล้ว

    Always good to see video's about power banks :) I would like to know how well the TP Link Ally ones stand up as they claim high capacity.

  • @davidb5255
    @davidb5255 6 ปีที่แล้ว

    Clive, do you have any recomnedations for good, high capacity, but not ridiculously expensive, 18650 cells? I have a set of 4 in an external battery pouch which came with some bike lights, but the capacity if terrible and the lights just chew through the pack in less than an hour, even on the lower settings. Cheers

  • @AndreasA.S.
    @AndreasA.S. 6 ปีที่แล้ว +1

    the green one has bluetooth so you can log the info on a computer or smartphone, i use this to monitor pulling Li out of sleep mode (over drained)

  • @matthewmiller6068
    @matthewmiller6068 6 ปีที่แล้ว

    Shouldn't you be measuring in watt-hours instead of mAH? That is what I usually do since modern packs I have like to run at 9-20 volts with QC or PD, watt hours usually line up
    Also is that big yellow meter one of them that does QC, PD, and USB-C?

  • @BerserkJeffy
    @BerserkJeffy 6 ปีที่แล้ว

    Another thing though, I watched some of your earlier videos and you were using one of those little load testers with winding resistors you can get off eBay for like 1USD -- As opposed to a light.
    Did something happen to that device or is the light just more convenient?

    • @bigclivedotcom
      @bigclivedotcom  6 ปีที่แล้ว +1

      The light is a good indicator of when the bank has cut off.

  • @seannot-telling9806
    @seannot-telling9806 6 ปีที่แล้ว +8

    Well I see you survived The New Year Party. I had to step out before the end.
    Now don't tease us OPEN the pack up.

  • @Matt_The_Hugenot
    @Matt_The_Hugenot 6 ปีที่แล้ว

    How for you account for the losses from the power bank circuitry heating early on that you mentioned?

  • @danhard8440
    @danhard8440 6 ปีที่แล้ว

    you have a link for the little yellow tester?

  • @Aco747lyte
    @Aco747lyte 3 ปีที่แล้ว

    That neat little 3W aluminium flashlight adapter can be got from Amazon or eBay quite cheaply. ETA: Also that USB Tester Power Meter - mine is a UM34C USB tester costing £26.99 from Innovateking-EU, but can cost a lot more so it pays to shop around.

  • @IrishSkruffles
    @IrishSkruffles 6 ปีที่แล้ว +1

    I always test the cells on their own whenever possible, and measure the capacity from fully charged to flat (using one of those imax chargers/dischargers)

  • @haulngrassracing
    @haulngrassracing 6 ปีที่แล้ว +1

    Wouldn’t discharging a battery or power bank more accurately give the correct capacity?

  • @barrygreengrass3379
    @barrygreengrass3379 6 ปีที่แล้ว

    Clive, please can you tell me what an acceptable quiescent current is for those circuit boards are?

    • @bigclivedotcom
      @bigclivedotcom  6 ปีที่แล้ว

      Some draw as little as 10uA in standby, but others draw a surprising amount of current.

  • @dodge911
    @dodge911 6 ปีที่แล้ว +1

    Interesting video :) If you want to know a little more on the RD UM24 (green) and UM34 (yellow) UPM's, I've got videos on both on my channel (or if you don't remember how to work the menu ;))
    Although I differ in opinion from you on getting a capacity-measurement : I'll discharge a powerbank at a certain current and monitor that along the way. I'll do this for every charging mode the powerbank supports.

  • @j.m.74
    @j.m.74 6 ปีที่แล้ว

    Happy New Year, Clive. 🍺😀

  • @oldmanhuppiedos
    @oldmanhuppiedos 6 ปีที่แล้ว +1

    You are an early bird again.
    An interesting vlog, but would you like to tell us more about the yellow (Rudaing??) controller?

  • @mouse454
    @mouse454 6 ปีที่แล้ว

    didn't you have a keweisi 5$ tester as well Clive?

    • @bigclivedotcom
      @bigclivedotcom  6 ปีที่แล้ว +1

      I do somewhere, but I like the Ruiden unit. It's got a very clear display.

  • @rexdoran2051
    @rexdoran2051 6 ปีที่แล้ว

    Did you get the Ruideng UM34C with blue-tooth? A couple of months ago I purchased a cheap android phone from China so I could load all sorts of dodgy apps without worrying (separate gmail account w/pre-paid credit card). The app for the UN34C is well worth checking out.

    • @bigclivedotcom
      @bigclivedotcom  6 ปีที่แล้ว

      I didn't. I'm always cautious about downloading apps like you describe. It really does require a separate account and system.

    • @rexdoran2051
      @rexdoran2051 6 ปีที่แล้ว

      I'll buy you one. I am a Patreon supporter, so you may be able to get hold of me through them.

  • @andysocool20
    @andysocool20 6 ปีที่แล้ว

    Can I give you some of my old electrical test equipment to tear down? Thanks

  • @jeffreyhebert5604
    @jeffreyhebert5604 6 ปีที่แล้ว

    Great video Mr Clive Sir... cheers.. Happy New year's to you and yours

  • @pomonabill220
    @pomonabill220 6 ปีที่แล้ว +2

    Is the true or closest measure of a LiPo cell during charge from minimum voltage, discharge at a constant rate to minimum voltage, or both?
    I have a "smart" charger (an icharger 208B) where I can set the charge current, and has a function where I discharge at a constant current, and it counts the Ahr during either one.
    For a LiPo cell (3.7v @ 2000 mAh) I usually set the charge current at about 400 mA and when I use the discharge function, the discharge current at 500 mA. I use the measured capacity from the discharge as the available capacity of the cell. Should I use the charge capacity instead? or will either one work?
    Recommendations/opinions?

    • @mrb692
      @mrb692 6 ปีที่แล้ว +2

      If you want to know how much power you can pull from the cell (arguably the more practical number), use discharge capacity.

    • @kingearwig
      @kingearwig 6 ปีที่แล้ว

      I charge my lipos at 1C.

    • @ethanpoole3443
      @ethanpoole3443 6 ปีที่แล้ว +3

      In the case if Li-ion and Li-Po cells specifically, the power you will get out is greater than 99% of what you will put in with proper charging, so it makes little difference. If you use a linear charging circuit (which is most common for these powerbanks) then the easiest way to determine the mA-hr rating is to fully deplete the battery to cutoff voltage then charge it using a USB power monitor that records accumulated mA-hr and figure that mA-hr rating at about 3.6-3.7V if you want to calculate W-hr. When discharging these power banks where there exists a 5V boost switching supply circuit you do not get an accurate recording of battery capacity because the boost circuit will have only 85-90% efficiency plus you need to account for the added mA-hr drawn from the battery to boost that 2.8-4.2V battery voltage up to the 5VDC (about 1.4x average multiplier) that is being output, so a lot more math is involved if you want to estimate actual battery capacity from the discharged power, hence measuring charge mA-hr is a much more straightforward alternative provided a linear charge circuit is being used by the device - if you encounter the rare powerbank that uses a buck switching regulator for charging then you are back to estimating battery capacity as you must then, again, account for the difference in voltage between input and output (5V to 2.8-4.2V) and the efficiency of the buck regulator, but most powerbanks use a linear charging regulator circuit for simplicity which make measuring charged capacity easiest. On the other hand, if you are measuring bare batteries (no intermediate circuitry other than charge protection) then for Li-ion you can simply measure charge or discharge power since they should differ by less than 1%, though with most other battery chemistries you would ordinarily want to measure discharge capacity to get true useful capacity.

  • @rogermckenzie2711
    @rogermckenzie2711 6 ปีที่แล้ว

    Happy new year, Clive! I assume either this video was recorded earlier or you have remarkable powers of recovery...

    • @bigclivedotcom
      @bigclivedotcom  6 ปีที่แล้ว

      I actually moderate the amount I drink carefully when I visit those particular friends.

  • @barrygreengrass3379
    @barrygreengrass3379 6 ปีที่แล้ว

    Clive, how do check the capacity of Non re-chargeable batteries i.e. Zinc, alkaline etc. Have you ever checked the capacity of Lidl’s Areocell batteries?
    The RUIDENG UM34 Voltmeter Ammeter displays & records mAh and mWh’s.

    • @bigclivedotcom
      @bigclivedotcom  6 ปีที่แล้ว

      I have a crude AA test setup that gives a useful indication of all AA style cells. It's a modified clock.

  • @keithking1985
    @keithking1985 5 ปีที่แล้ว

    Are those modules the U24 or the U34 Bluetooth????

  • @BerserkJeffy
    @BerserkJeffy 6 ปีที่แล้ว

    Back again. So I measured my one phone, a Nexus 5X, from flat to full and it came out around 2300 mAh. Supposed to be 2700mAh new. Makes sense to me. I think I used the mWh reading and converted it down to mAh @ 3.7V
    I know that normally this would be difficult to measure at all since usually you charge a phone while it's on, so I did it while it's off, hopefully keeping the draw down.
    That's not my Daily phone though. It's one of the models that had a widespread bootloop issue, so now it's really slow to use.
    The replacement was a Doogee S60. A brick of a phone. I noticed a lot of lies in their advertising. Like they say it has stereo speakers, it's only got one for media playback. They say the charger's capable of 12v 2A (so 24W) charging, I can only get 9v1a, or 5v1.4a out of it.
    They say the Battery is 5580mAh. So of course I want to measure that.
    Ran it flat. charged it to full while it's off. The numbers are confusing. It started at 5.12v 1.4a and went down to 5.02v .25a by the end.
    Ruideng says it used 3080mAh. Being generous and using the max voltage to convert that to mWh, 15769. Down to 3.7v, 4262 mAh.
    The Ruideng also said it used 23835 mWh, which I think is what I used to measure the 5X before, and THAT converted down to 3.7v is 6442 mAh.
    Since neither of these are close to the stated capacity, and I've had the Doogee for a year, would you think the mAh -> mWh -> mAh reading is more accurate or the flat mWh -> mAh?
    If you read all that, thanks a ton! Also never buy a Doogee phone, Clive.

  • @stalwartcomputers5182
    @stalwartcomputers5182 6 ปีที่แล้ว

    We've been working with a company called R&D and they've done great in providing us a range of these ammeters with tight specs (we've created 4types with them atm & have a couple of false load devices in the pipeline atm) there is great monitoring software with them aswell😉

  • @johnfuqua1143
    @johnfuqua1143 6 ปีที่แล้ว

    I acquired a lot of knowledge from this Vlog. I was wondering if they would be changing the meter from USB A to USB C or would an adapter be sufficient ?? Have you looked into the Handwarmer +power banks???

    • @bigclivedotcom
      @bigclivedotcom  6 ปีที่แล้ว

      It has extra connectors for micro USB and USB-C on some models. I took one of the hand warmer packs apart in another video.

  • @skullpassmore
    @skullpassmore 6 ปีที่แล้ว

    could you use a constant load device to measure the capacity of a battery?

  • @James_Ryan
    @James_Ryan 6 ปีที่แล้ว

    Good stuff! Does the ambient temperature make a difference to capacity of lithium cells during charging and discharging? Electric cars charge slower and have less capacity at low temperature (30°C is optimal), and alkaline delivers most capacity at 20°C during discharging...

  • @dizzym9554
    @dizzym9554 6 ปีที่แล้ว

    Can you link to the one you're using? (The yellow one) I'm definitely interested in doing some tests myself.

  • @MrBlackdragon1230
    @MrBlackdragon1230 6 ปีที่แล้ว

    Just as a heads up I have a battery charger that will test the capacity as well as charge them, it's also not very expensive. You might even find it interesting, it's called MiBoxer C4. Got it on Amazon for less than $30 usd.

  • @croyce7699
    @croyce7699 6 ปีที่แล้ว

    Interesting that you say the Uni-T metres are fairly good. AvE seems to have a differing opinion.

  • @therealjammit
    @therealjammit 6 ปีที่แล้ว

    I remember when nickle cadmium was the thing before Li+ existed. I would trickle charge a battery until I knew it was fully charged (a few days, doesn't hurt them). I had a modified analog travel alarm clock. Instead of it having a battery, I installed a resistor and some wires. I would set the clock to 12:00 and hook up the charged battery to it through an ammeter. I would write down the current at the start and finish of the discharge and take the average (close enough) of that current and divide it by the hours the clock ran to get the AH of the battery.

  • @BadBrad23
    @BadBrad23 6 ปีที่แล้ว

    I have a Imax b6 charger. They are on Ebay for like 20 bucks. They have all the connectors and can charge/discharge most any type of battery. I have used it a few times and works pretty good.

  • @TheRealColBosch
    @TheRealColBosch 6 ปีที่แล้ว +11

    "I wiggled it and it went bang." That's what HE said!

  • @electroniquepassion
    @electroniquepassion 6 ปีที่แล้ว

    Bonne video 👍 bonjour de la France 🇫🇷

  • @PIXscotland
    @PIXscotland 6 ปีที่แล้ว

    The only issue I have with this type of charge testing (And I do it myself) is that the readings are distorted by the efficiency of the 5vUSB to CellVoltage conversion. I believe this method will always measure the capacity with about a 10% over-read. The same stands for the discharge of the cell. They will typically under-read by about 10-15% due to the measuring at 5v as you said around 14:00. I guess these numbers are close enough for general use though.
    I built, but never published, a tester based on an Arduino and a couple of constant current drivers that I feel gave better values for capacity. It measured the capacity using time and a fixed current of either 1A, 100mA or 25mA based on voltage triggers. I might drag it out and publish it sometime soon as I've never seen this done anywhere else.
    Sorry for waffling! :-)

    • @bigclivedotcom
      @bigclivedotcom  6 ปีที่แล้ว +3

      With the simple current regulation the current is constant through the whole circuit. So the current being measured by the mAh counter is exactly the same as is passing through the lithium cell. It's only on some more sophisticated power banks like potentially the Duracell one that buck regulation skews the result.

    • @ethanpoole3443
      @ethanpoole3443 6 ปีที่แล้ว +1

      bigclivedotcom To add to Clive’s comment, that is true during DISCHARGE as most power banks use only a simple linear voltage/current regulator during charging for simplicities sake - this means that the mA-hr reading you read when charging a depleted battery will ordinarily match that of the battery to within better than 1%...and if you want battery Watt-hours you would multiply that mA-hr figure by the battery nominal voltage of 3.6-3.7V.
      But during discharge you must account for not only the added power draw the battery sees from the boost regulator boosting 2.8-4.2V up to 5VDC but also for the 85-90% efficiency of that boost circuit plus whatever load your USB power monitor may add - so determining native native battery capacity during discharge is more complex, but determining such during charge is usually trivial and since the efficiency of Li-ion batteries is better than 99% you may as well use the charging figure since it will be off by less than 1%.
      However, there are a few charge banks out there (particularly those with fast charge support) that use more efficient buck regulator’s during charging in which case the best you can do, short of removing the battery and measuring directly, is to measure the Watt-hours used during charging and then multiplying that figure by 0.85 to 0.9 to compensate for the inefficiency of the buck regulator since, in this case, the Watt-hours figure is the most trustworthy number to go by with a switching regulator and then derive the battery mA-hr rate based upon its nominal 3.6-3.7VDC (so, real Watt-hours equals measured W-hr multiplied by 0.875 and to get Ah figure you would divide the real W-hr figure by 3.7V).

  •  6 ปีที่แล้ว

    Still got a question for 18650. Personally when i test mines, i drop them to 3.6v and stop at 4.2v or vice-versa. Are there some official standard for initial and ending voltages?

  • @ThunderBassistJay
    @ThunderBassistJay 6 ปีที่แล้ว

    How about loss due to dissipation in the cells during charging?
    It's a pity that capacity isn't specified in joule or watt hour.

  • @Furiends
    @Furiends 6 ปีที่แล้ว

    The "tight" power bank is only meant to take a cell that doesn't have a protection circuit. The protection adds a little bit to the length of the cell. Most things that receive 18650s can fit both lengths. Considering thats a "DIY" style USB battery its pretty much a defect of design not to accommodate both lengths.

  • @xuanmai7133
    @xuanmai7133 5 ปีที่แล้ว

    is there an app that can use to determine actual mah of a power bank?

  • @MADMODS
    @MADMODS 6 ปีที่แล้ว

    Clive can you test a lipo safety charging bag to see how safe these things are. I mean put a Lipo in a bag and overcharge it and see how or if the lipo bag makes any difference to the battery going up in flames. I know you love lipos and flames