Dear all,
I have designed a system which uses a 7.4 V, 6,6AH Li-Ion battery pack (18650) in the configuration 2S-3P. It is charged using a uC based software algorithm which is CC till 8.4V and then CV till current falls below 0.05C. I charge the battery using a 12V DC charger or a 15W, 12 V Solar Panel. Obviously there is a buck-converter in between which manages the voltage applied to the battery.
Recently I came across situations that batteries which go to sleep would not revive using the software charger. I had an earlier version of the same system using a different microcontroller SH4 from Freescale, which would wake up the battery. However the new version uses a different microcontroller MC9S08PA4VWJ which does not work. The only change is I see is the speed of operation - it was 12KHz for the buck converter PWM earlier and now it is around 35KHz.
Can any one suggest what is wrong or what I should try? Please ask if you need more information.
Thanks in advance
I have designed a system which uses a 7.4 V, 6,6AH Li-Ion battery pack (18650) in the configuration 2S-3P. It is charged using a uC based software algorithm which is CC till 8.4V and then CV till current falls below 0.05C. I charge the battery using a 12V DC charger or a 15W, 12 V Solar Panel. Obviously there is a buck-converter in between which manages the voltage applied to the battery.
Recently I came across situations that batteries which go to sleep would not revive using the software charger. I had an earlier version of the same system using a different microcontroller SH4 from Freescale, which would wake up the battery. However the new version uses a different microcontroller MC9S08PA4VWJ which does not work. The only change is I see is the speed of operation - it was 12KHz for the buck converter PWM earlier and now it is around 35KHz.
Can any one suggest what is wrong or what I should try? Please ask if you need more information.
Thanks in advance