Hi All,
After watching Dave's video, I have ran into a few issues with my Li-Ion system, I figured this problem might be common and help some people or maybe I am just having a mis-understanding. Any help would be greatly appreciated.
I am having an issue recharging a single cell Li-Ion battery that contains a protection IC, after the IC has gone into protection mode from an over-discharge of the battery.
I am using an MCP73831 charger to charge the battery. Off of the battery, I have a comparator with a built in voltage reference that monitors the battery voltage and shuts off the main system regulator if the battery voltage drops below 2.9V. At this point, the total system current is about 5 microamps. It takes a long time, but eventually, this small current draw reduces the battery voltage enough to cause the protection IC to go into over-discharge protection mode. The problem is, that once the protection IC is in over-discharge protection mode, the charger will not cause the system to come out of protection mode, and hence the battery will not charge.
The datasheet for the protection IC states that when the system is in over-discharge protection, to get the system out of protection, the terminal voltage must rise above the "Over Discharge release Voltage" (2.9V - 3.0V).
I don't understand how this situation will ever occur, since the battery is disconnected and the charger is feeding the battery with current, there is no current path because the protection IC's discharge FET is off, I don't understand how the charge current can ever cause a voltage to develop and release the battery from protection?
Any help, solutions, suggestions would be very appreciated!!
Thanks so much!
Dan
Here is a link to the protection IC datasheet:
http://www.hycontek.com/attachments/Battery/DS-HY2110_EN.pdfAnd the datasheet for the charger:
ww1.microchip.com/downloads/en/DeviceDoc/21984a.pdf