I don't think this is right ?

Hi all - Batteries are Sanyowith a yellowish ring on top. I have check the database it doesn't seem even close to the highest mAh of Sanyo batteries.
It's displaying 5000+ and 4000+ mAh


any thought ? faulty charger ? (it's new, few weeks old)

Thanks

Your cell tester is fine. It's showing the energy it has used so far trying to charge the cells. Those Sanyo's have a reputation around here for getting hot while charging (search the forum for "Sanyo heaters". If you feel them you will find they are very hot, so most of the power is being burned off as heat, resulting in abnormally high mAh readings and extended charging times while it tries to get the cell up to 4.2V

watts-on said:

Your cell tester is fine. It's showing the energy it has used so far trying to charge the cells. Those Sanyo's have a reputation around here for getting hot while charging (search the forum for "Sanyo heaters". If you feel them you will find they are very hot, so most of the power is being burned off as heat, resulting in abnormally high mAh readings and extended charging times while it tries to get the cell up to 4.2V

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Shall I avoid them then ? how can I know the real capacity then ?

g3org3s said:

watts-on said:

Your cell tester is fine. It's showing the energy it has used so far trying to charge the cells. Those Sanyo's have a reputation around here for getting hot while charging (search the forum for "Sanyo heaters". If you feel them you will find they are very hot, so most of the power is being burned off as heat, resulting in abnormally high mAh readings and extended charging times while it tries to get the cell up to 4.2V

Click to expand...

Shall I avoid them then ? how can I know the real capacity then ?

Click to expand...

If they ever show "full" do the discharge test, that's what matters - record the mAh final result, then repeat the charge then discharge test again. You'll likely see a capacity (discharge) reduction after each test, which is why you'll hopefully decide not to use them for anything you'd expect to be functional for a lengthyperiod of time.

@g3org3s
watts-on is right the tester is most likely fine the cells are bad the internal IR of theses cells is most likely over 100m?.
The Tester is trying to push the last amount of amperage into the cell but the cells resistance is burning up the energy in the form of heat and the Voltage never gets to ~4.2V so the charge can finish.

Now the OPUS quick test is by no means an accurate representation of the actual IR of the battery but I suggest you enter the quick test mode and you will probably see an IR of over 200 and maybe even higher.

You are probably talking about the UR18650Y which for a good cell should have an IR of ?50m? and a marginal high of 57m?
Proper IR can only be measured with a 4 wire Kelvin 1kHz AC m? meter such as the YR1030

You can experiment as sean indicates but yes I would definitely not use them.
Wolf

+1 with Seans comment about "discharge test". When charge testing, the charger has no way of knowing what is being converted to heat, unless you get a really expensive piece of equipment.
The discharge test is the one that will give you real world capacity values, or at least pretty close.

As far as heating is concerned, there are many threads on here about "Sanyo Heaters". There's basically two groups of people on the subject. One group says toss them without a second glance, the other group says to cycle them a few times and if the heat produced goes down (usually rather quickly each time) and the capacity comes up, then they are fine. Each person needs to address what they feel safe with and make an educated decision.

Korishan said:

+1 with Seans comment about "discharge test". When charge testing, the charger has no way of knowing what is being converted to heat, unless you get a really expensive piece of equipment.
The discharge test is the one that will give you real world capacity values, or at least pretty close.

As far as heating is concerned, there are many threads on here about "Sanyo Heaters". There's basically two groups of people on the subject. One group says toss them without a second glance, the other group says to cycle them a few times and if the heat produced goes down (usually rather quickly each time) and the capacity comes up, then they are fine. Each person needs to address what they feel safe with and make an educated decision.

Click to expand...

Again there are some preliminary factors that need to be addressed when testing cells. It really doesn't matter what the cell manufacturers is but Sanyo seems to be the most susceptible to the 'heater" phenomenon.
I have some CGR18650EA cells right now with a higher than normal IR that I just ran a charging test on at 500mA.
Result is a 45C + charging temp. Totally unacceptable. The same cells with an acceptable IR barely get to 30C while charging.
If a cell shows any "heater" tendencies I would not use them in a powerwall period. It takes a lot of time to build a proper pack just to have to chase a "heater" in the end. Can those cells be used in something else? Absolutely as long as the capacity is within what you are looking for and you dont stress the cell. I do have to disagree with the other groupthough. I have not seen any serious heaters come up in capacity and maintain that over a course of cycles.


Wolf