UNI-T UT658 TESTER AS A BATTERY CAPACITY TESTER?

[@GEspok]

Li-ion batteries should normally be tested at a constant current of 0.2C, according to standards. In this case, as the rated capacity of the batteries is 5000mAh (if I read that correctly somewhere in the video), the constant current to be used here should be 5000*0.2=1000mA=1A. Hence, in my view, the second method shown in this video should be favoured for battery testing and comparison. Thanks to Paul for this nice video!

[@pacikamail]

Keep in mind, that the UNI-T ran at boosted 5 volts, the others at the nominal 3,7. I think there might be some issues with the booster gadget too. It said, that the UNI-T can run at as low as 3 volts, you might try to feed it with a bare cell, or with the two of them in series.

[@cheeseschrist2303]

Yes, I agree. Feeding with a bare cell would be preferable, and the 3 volt cut-off would act as protection circuit, and maybe level the playing field. Yes, 5v with protection circuit and boost converter, compared to vanilla 3.7v battery, it's like comparing apples to oranges. I use a different USB tester which can measure mWh which gives a more accurate indication of capacity. 1 Amp @ 5 volts = 5 Watts; 1 Amp @3.7 volts = 3.7 Watts; 1 Amp @ 3 volts = 3 Watts. Also the mAh reading increments by 2 or 3 mAh @ 1 Amp load and 5 mAh @ 2 Amp load.

[@E-BikingAdventures]

I'm wondering if the battery protection circuits on the TP4056 had any contribution to the lower results. Also, I think you should have done an additional test with the ZB2L3 using a 1 amp load instead of just the 0.5 A from the single 7.5 ohm resister.

[@catkiller395]

Great video! But there are conversion factors that need to be taken into account. The UNI-T tester is running at around 5V and the others, at an average of 3.7V. So it would be a better comparison if Watt-hours were used as the measurement of energy capacity (since Wh = V * Ah). That would level the differences quite a bit. Not to mention, the boost converter is not 100% efficient (probably around 85%), and the capacity tester itself is using energy to run itself.

[@ehobbyguy8980]

Samaunus Safa great feed back thank you very much and thanks for watching!!

[@radionutio81ij79]

I have one of these units and i have tested it against a few other testers its quite accurate, i would assume that your unit has a possible manufacturing defect a replacement is in order me thinks.😊

[@ekoenig21video72]

Your load on each of those testers is different, so I believe you are getting a different capacity reading accordingly. I believe I read somewhere that the constant test, with the resistor, you would take the voltage (3.7) divided by the resistance (7.5) to get the A (~.5). So with that said, you are testing once with a draw of 1 A and once with a draw of .5 A (between the ~1200 and the ~1600) so not an equal test. As far as the USB tester goes, I would imagine that the draw by the USB tester itself is pretty substantial, it is running an LCD, so the 1 A that you put on there does not include the draw by the USB tester, so you are potentially doing a draw of ~3+ A using the USB tester, you would have to plug that tester into another tester to figure that one out. Without being able to get the draw equal you are comparing apples to oranges on this one.

[@FrancisRodgers]

I often see such discharge units discharging the batteries using a resistive load. It would be interesting to see if there are any units that can discharge to either a capacitive load or an alternative battery. This way the power can be reused.

[@SODA-iz8lc]

Okey then, to come to a conclusion, which of those 3 testers do you trust the most? I would really appreciate it if you can answer it Sir