I am looking to charge a 3-cell stack (3S1P) of 3.2V LiFePO4 105Ah Batteries. Charge current would be 4-5A with an input of 12vDC. The charger chip needs to have standalone operation, there is no uC in this project. I am looking at the LTC4020, is this the best fit for this application? I do not need the power path control and do not plan on using it.
The product is a backup supply for emergency phone systems. The basic system would be 1, 3 cell battery stack (3S1P) ~10v. There could be a second battery system stacked on top of the first to increase the output to ~20v. Each 3 cell battery stack would have its own charger.
The customer has an existing board (they insist on using) that manages and tests each cell in the battery to make sure it is functional. The customers board gets 2 supplies, one is a 12vDC supply for normal operations. The second is a standalone charger (LTC4020) that runs thru their board to the battery. The customers board has the ability to connect and disconnect just about any input to any output. They are handling the power path decisions and don’t want to change any code.
They can disconnect us from the battery and test each cell individually and then reconnect us at any time while the 12vDC is active. I assume this can happen while we are charging, the charger would need to be able to resume charging if needed when reconnected.
The output we get from them can be either the 12vDC power supply or the battery voltage from a basic system or 24vDC or the 2 battery stack from a stacked system. Which we then boost to 48v at about 2 Amps max to run the phone system, I am looking at the LTC3784 for the boost supply.
So, my question is the LTC4020 the best choice for this appliccation?
I look forward to your input.
Thank you
Ben