Bad Lipo Cell

[EBJ]

Yes, it helps reduce the effect of the dud cell.
They literally work as if they were one cell, each balancing each other out constantly.
The more good cells you put in parallel with it, the better.

But that cell group will always be a bit more stressed over a long period of time; eventually it will be the one that dies before all the others.

For example if you have a 20ah pack, and one cell group has 17.5ah, you are giving that cell group a fuller depth of discharge every cycle. You are effectively making one cell group work 12.5% harder.

Thanks that answers all my questions.

 

[retro]

What I neglected to mention in my previous post is that I do balance the taps on a balance board when charging, just not when in discharge. I have been very pleased with the batteries until I did my century ride last weekend... I was tired near the end of this ride and pushed the batteries to 33 volts under load, according to my CA.

My only issue is that the iCharger requires absolute calibration. If anything, I believe the voltages from the charger are low, so I'm not getting actual 41 volts from 10s packs. My CA has been calibrated with Lyen's internal shunt value, and the CA never reads 41 volts hot off the charger... somewhere around 40.5 to 40.7 volts. I tried to calibrate the iCharger with two voltmeters, unfortunately, one of the meters was wayyyyy off, so I need to calibrate with something within a millivolt of each other. These are tight tolerances.

With this in mind, my charger is charging low, the CA cuts off correctly... therefore, I'm not getting full usage of the batteries. Unfortunately, I did 108km on Saturday and another 108km on Monday last week, so I probably over-worked the batteries, twice. Using the lower end of their power vs the higher capacity that never got used.

 

[neptronix]

That's interesting. i have never heard of an iCharger being off by 0.1v.

You can set the per cell value to balance to in the settings. I think it varies from 4.0-4.3v for the lipo setting.
So it is more important to make sure all the balance leads read equally rather than the overall pack voltage.

Set your iCharger to 4.25v/cell and see what happens. Verify with your multimeter.

 

[Ykick]

That's interesting. i have never heard of an iCharger being off by 0.1v.

You can set the per cell value to balance to in the settings. I think it varies from 4.0-4.3v for the lipo setting.
So it is more important to make sure all the balance leads read equally rather than the overall pack voltage.

Set your iCharger to 4.25v/cell and see what happens. Verify with your multimeter.

There's another hidden menu where the individual balance channels can be adjusted quite a bit IIRC. Mine drifted on 2 different balance taps and those cells were coming up lower than indicated.

I only noticed it in the 1st place because of many different devices (Cell Logs, BM6, etc) to help watch the results of the iCharger..