Boost converter for motors can prove to be rather beefy, as Iin>Iout*(Vout/Vin). Or you use separate boost converter to generate ~4.5-6V and then drop it with linear regulator. Other major players like TI, ON, NXP or Microchip should also have something. LTC3440 comes to mind, and also one from Maxim, but I cannot recall the number right now. There are specialized ships that do just that, even with single inductor. 3.3V is somewhat inconvenient, because in order to get that from a single cell you need a buck-boost converter as the cell voltage varies roughly from 2.9V to 4.2V. Most logic nowadays runs fine from 3.3V, and some even from unregulated li-io voltage. You can use a big boost converter for powering motors and a separate one for powering logic. Any opinions, experiences, tips are welcome in the topic. And when we talk about li-ion safety in a consumer device, I would rather not take reliability lightly. I read about custom charger and monitor solutions with voltage references, op-amps, ADC-s with a single microcontroller, but to develop a reliable and accurate custom solution from ground up seems a whole lot of work, knowledge and experience in this area. I am surprised that I haven't found a single charger IC with balancing capability! - Is there a simpler / cheaper / more integrated solution? Other than building the whole circuit from 3-4 different chips? - Best way to measure SoC? I don't need ultimate precision, but enough to keep the user happy with more or less reliable reports, and to be able to fully utilize battery capacity. Balancer IC-s are rare, and ofter part of a complex monitor chip. My quetsions - Do I need balancing? My understanding is that the average discharge rate is below 1C, balancing is not crucial. ), but often they are wildly complex for my application, or expensive, and I would prefer leaded packages for hand soldering, which narrows the possibilities. I did my research on the various IC-s of different manufacturers (TI, Linear, Microchip, Maxim.
Optionally, a balancer solution would enhance battery life and safety. (The supply will be an external 12V wall charger) - And I need the State of Charge of the battery, preferably with a coulomb-counting based method, as the OCV (open circuit voltage) -based solutions are inaccurate, especially during charge/discharge. I definitely need some kind of battery protection (under-, and over-voltage, over current, short-circuit) - I also need a charger solution with 1.5-2A charging current. The battery pack I use is a bare 2S puch cell pack with no internal protection circuit. The peak current draw can be up to 4A, the average is around 0.5A (uC, motors, LEDs).
Hi, I'm designing a full-fledged battery management solution for a 2S Li-po battery pack in a custom consumer electronics device.