Johnny Kang
Newbie level 4
Hi, I want to build my very first li-ion charger, so any help and tips are much appreciated. I've only worked with digital circuits, so my experience in this area is close to zero.
I have a 5s6p li ion ncr18650b battery pack that's going to power my portable desktop. I'm planning to use a BMS(battery management system) for 5S with overcharge/overdischarge/overcurrent/temperature/short-circuit protection with cell balancing option. I'm looking at http://www.bestechpower.com/communicationbms/BMS-D298V1.html
which also comes with a smbus comm which can be interfaced with a simple driver.
What I'm struggling with is converting my 21V(24v psu with buck circuit) DC power supply into a current limited supply that can safely charge each cell at less than 1C, so 6C for the entire pack. For the sake of simplicity and weight(would prefer to keep the charger by itself less than 200g) I'm looking for a simple method of charging slowly until the battery reaches 21V and then shutting off( a single stage charger, not like CC/CV chargers with IC).
That being said, I wouldn't mind working with li ion charger IC, but I'm having a sort of decision crisis with so many to choose from!
Here is a simple diagram to explain my system:
Again appreciate any advice!
I have a 5s6p li ion ncr18650b battery pack that's going to power my portable desktop. I'm planning to use a BMS(battery management system) for 5S with overcharge/overdischarge/overcurrent/temperature/short-circuit protection with cell balancing option. I'm looking at http://www.bestechpower.com/communicationbms/BMS-D298V1.html
which also comes with a smbus comm which can be interfaced with a simple driver.
What I'm struggling with is converting my 21V(24v psu with buck circuit) DC power supply into a current limited supply that can safely charge each cell at less than 1C, so 6C for the entire pack. For the sake of simplicity and weight(would prefer to keep the charger by itself less than 200g) I'm looking for a simple method of charging slowly until the battery reaches 21V and then shutting off( a single stage charger, not like CC/CV chargers with IC).
That being said, I wouldn't mind working with li ion charger IC, but I'm having a sort of decision crisis with so many to choose from!
Here is a simple diagram to explain my system:
Again appreciate any advice!