Re: BMI PRO-6 + Dual Power 80W (B6 Clone) Cell 1 voltage display

[Paweł Si]

2016-04-15 17:17 GMT+02:00 Armin Beyel <armin...@gmail.com>:

Hi, i was not satisfied with this Charger. It didn't load to full capacity. I think it was because of wrong or no calibration.

I flashed the Atmega32 with the: "cheali-charger-imaxB6-clone_1.99-20160411_atmega32" firmware.
I erased eeprom and made all calibrations.
I calibrated the cell voltages with a resistor network,

please use a battery for the voltage calibration, you don't need to calibrate all cell ports.

 

because i don't have any 6 cell lipo or adapter for 2 3S.

you don't  need a 6 cell battery, a 2 cell will also do the job.

 

I measered with a calibrated tektronix multi meter.

The first loading displayed a cell 1 voltage of 4.32 V instead of measered 4.17 V.
Do I need to do the special calibration (Calibration - Expert (IMAX B6 and clones only)) for cell 1 and 2 voltage measuring?

 

No, the  "expert" calibration is not needed.

It is possible that you charger differs from Imax clone, 

try also the cheali-charger-Dual-Power-B6AC-80W-RC_[version]_atmega32.hex firmware,

you could also send a picture of your charger's PCB.

[Armin Beyel]

This is my charger.

This is the PCB:

This is the programming connector I added:

I already changed the firmware to: cheali-charger-Dual-Power-B6AC-80W-RC_1.99-20160411_atmega32.hex
Calibration is no big problem. I have a resistor network simulating 6 cell, powered with 24 V. I meassure each cell voltage and correct the Vb1 to Vb6 settings.
For current calibration I use an old 2S 4000 lipo (70 % charged).

After testing "charge and balance" a 3S lipo, I measured maximum 2 mV difference to the end voltage of 4.20 V.
I have two of this chargers and I hope, they are better now than with the original firmware.
I think this chargers were not calibrated before. The charging results had big difference between the two chargers. One charger had about 20 % lower capacity than maximum.

I hope I can help with this pictures and experience.

[Paweł Si]

2016-04-16 18:59 GMT+02:00 Armin Beyel <armin...@gmail.com>:

I already changed the firmware to: cheali-charger-Dual-Power-B6AC-80W-RC_1.99-20160411_atmega32.hex

yes, based on your PCB you should use: cheali-charger-Dual-Power-B6AC-80W-RC_1.99-20160411_atmega32.hex

(your PCB has an additional op-amp in the upper right corner: see pic)

 

Calibration is no big problem. I have a resistor network simulating 6 cell, powered with 24 V. I meassure each cell voltage and correct the Vb1 to Vb6 settings.

using a battery for voltage calibration is always better than a resistor network,

(because of the small internal resistance)

[Armin Beyel]

I will make an adapter for two 3S lipos then I will calibrate voltage again.

Best regards

Armin