I am looking for a simple 4 cell (INR-21700-P42B) battery BMS and fuel gauge solution. The batteries are in an outdoor box for powering a rocket launcher. I would like to monitor the state of the batteries remotely during launches, so some sort of interface to the Raspberry Pi on the launcher board is needed. The Pi provides a web interface for the launcher, so I could add a page that shows the state of the batteries. A LED fuel gauge on the battery board is a plus. Charging is done away from the launch site.
So far, I have found a cheap BMS from Amazon (~$10 for https://www.amazon.com/dp/B08NJTS9DV?psc=1&ref=ppx_yo2ov_dt_b_product_details) to manage the charging and balance the cells. Any recommendations for a single chip solution instead of the whole board? I think this board is the cheapest solution, as once I start adding the other support circuitry for balancing the cells (FETs etc.), it will cost more than this board when I go to JLCPCB to make the board and assemble the SMDs.
For the fuel gauge, the first idea I had was to use a couple of op-amps as voltage followers, one for each cell, appropriate resistor dividers on each output to level shift the output voltages to 0-3.3V, and a ADC on an SPI bus to measure each cell voltage. Simple, and probably not that accurate.
Then, I found the Analog Devices MAX17263, and it looks promising. Has anyone on the list used this device? Any gotchas I need to know about?
I looked through the TI chip finder (https://www.ti.com/power-management/battery-management/fuel-gauges/products.html#1152=2-4 Cells&) and most of the options require purchasing an evaluation board and Windows software to set up the chips. I don't have any Windows software - I am an open source Linux guy and I don't have a budget for an evaluation board. Many of them also use other bms related chips. I am not a battery/bms expert so I am a bit overwhelmed by all the choices and nomenclature.
I would welcome any recommendations for better/cheaper BMS and fuel gauge options.
Thanks!
So far, I have found a cheap BMS from Amazon (~$10 for https://www.amazon.com/dp/B08NJTS9DV?psc=1&ref=ppx_yo2ov_dt_b_product_details) to manage the charging and balance the cells. Any recommendations for a single chip solution instead of the whole board? I think this board is the cheapest solution, as once I start adding the other support circuitry for balancing the cells (FETs etc.), it will cost more than this board when I go to JLCPCB to make the board and assemble the SMDs.
For the fuel gauge, the first idea I had was to use a couple of op-amps as voltage followers, one for each cell, appropriate resistor dividers on each output to level shift the output voltages to 0-3.3V, and a ADC on an SPI bus to measure each cell voltage. Simple, and probably not that accurate.
Then, I found the Analog Devices MAX17263, and it looks promising. Has anyone on the list used this device? Any gotchas I need to know about?
I looked through the TI chip finder (https://www.ti.com/power-management/battery-management/fuel-gauges/products.html#1152=2-4 Cells&) and most of the options require purchasing an evaluation board and Windows software to set up the chips. I don't have any Windows software - I am an open source Linux guy and I don't have a budget for an evaluation board. Many of them also use other bms related chips. I am not a battery/bms expert so I am a bit overwhelmed by all the choices and nomenclature.
I would welcome any recommendations for better/cheaper BMS and fuel gauge options.
Thanks!