Storage or Storage+Balance is very slow the charge/discharge is done with less than 1C

[Nandox7]

I noticed that in the storage or storage+balance mode if the charger needs to charge the LiPo to reach the 66% of charge it doesn't charge it not even at 1C.
For example on a 1300mah LiPo it was charging at ~350mah and this makes the process take hours to complete. Shouldn't it be charging at least at 1C?

What I do now it to charge and stop manually around 66% and then run the storage program but if I get distracted and it passes that value then again I have to wait hours because the discharge rate is even more slow.

[stawel]

"Shouldn't it be charging at least at 1C?"
Yes, it should.

let us consider only "storage" (it's much simpler then "storage+balance")
so, I need more info:

1. how many cells has the battery?
2. what was the voltage on each cell at the beginning of the "storage" program?
3. what was the current at the beginning of the the "storage" program?

[Nandox7]

I'll collect and share some more precise details.
But just for a start I had this happening with 3S and 4S, I usually drop my cells up to 3.7v so that should have been the initial cell charge.

[Nandox7]

Test with a 1300mah 3S LiPo.

Details:

1. 3 cells
2. 3.69v
3. 197mA

[stawel]

can you give me the voltage for all cells (separately) and also the measured resistance for all cells?
I'm assuming the current didn't increased after a while?

[Nandox7]

I stopped the program but I restarted it again. See the values bellow:

Cell voltage:

1. 3.70v
2. 3.71v
3. 3.70v
   Batt resistance: 99mΩ
   Current: 197mA

[stawel]

interesting,
what is the resistance on each cell separately?
and you are running "storage"?
what cheali-charger version are you using?

[Nandox7]

The fw version is 0.32m.
Individual cell resistance is:

1. 35mΩ
2. 21mΩ
3. 42mΩ

I left it running until now and it changed from 52% to 57% in 30min. If it was to raise to 66% when it stops it would be almost 2hrs waiting.

[stawel]

please install the "not_tested/cheali-charger-[?]-0.33.hex" version.

The "%" value is not important.

How the "storage" program should work, the charger should:

1. charge at 0.1C for a moment
2. jump to 1C until one of the cells voltage reaches 3.850V
3. go down from 1C to 0.1C so that the voltage remains at 3.850V
4. stop charging

If the 0.33 version is not working as above,
I will need from You a short video (about 3min long) of the "storage" program running,
for now it's difficult for me to judge what is going on there.

[stawel]

unfortunately you will need to calibrate the charger again after installing the 0.33 version

[Nandox7]

All done, 0.33 loaded and calibrated.
Tried again with the same LiPo and same happens, check the video bellow.

https://www.youtube.com/watch?v=3TVlw_WvViA

Just 1:30 but even after 20min it was still only charging at 212mah.

[stawel]

Thanks for the video,
hm... I have no idea why this is so, the current should jump to 1C,
I will do some test today, maybe I will find something.

And the charge process is working normally at 1C?

[Nandox7]

Yes. The charge process works fine.

Minor issue there as it leaves the cells a bit bellow 4.20v but I usually
compensate in the calibration area and it gets perfect.

[stawel]

Indeed, there was a bug in the firmware,
I've uploaded a new version to "not_tested/cheali-charger-[?]-0.33.hex"
please check if it works now.

Best regards,
Paweł

ps. "Minor issue there as it leaves the cells a bit bellow 4.20v"
This may be addressed in the next version

[Nandox7]

Seems like you nailed it.
The LiPo as almost at storage level but I could clearly see the charge raise to 1C and then lower down but always to much higher values than before. I'll test it better tomorrow if I get some discharged LiPo's.
Great work, thanks!