2S battery charging IC recommendation request

[junaid]

Hey everyone! We're working on a project where we need to charge up 2S li-ion battery with a charger/charging IC  that can handle different types of power sources like USB, solar panels, and even a water turbine!

Basically, we need a charger that can pick the best power source available and keep our batteries safe while charging. If it already has safety features, great! But if not, we'd like suggestions for how to add them.

Here's what we need:

1- It should be able to use a USB 5V Input.

2- It should also work with solar panels. We found one we like [ https://www.digikey.com/en/products/detail/anysolar-ltd/SM351K09TF/14311422 ].

3- And it should work with a water turbine like this one [ https://www.amazon.com/gp/product/B095P35MZC/ref=ppx_yo_dt_search_siln_title?ie=UTF8&th=1 ].

Please someone expert let us know a charging IC  that fit these needs, or if have any schematics or guides that could help us out, we'd really appreciate it! Thanks a bunch!

[aliarifat794]

you can consider using the BQ24650 charging IC from Texas Instruments.

[mariush]

I like MP2672 / MP2672A from MPS  (the A version is newer) :

MP2672A : https://www.digikey.com/en/products/detail/monolithic-power-systems-inc/MP2672AGD-0000-Z/13572801 or https://www.digikey.com/en/products/detail/monolithic-power-systems-inc/MP2672AGD-0000-P/13572796

MP2672 : https://www.digikey.com/en/products/detail/monolithic-power-systems-inc/MP2672GD-0000-Z/13159530

It has i2c to set some parameters but also works in standalone mode, storing in internal memory the settings.

It takes 4v to 5.75v and boosts it to the voltage you'd need to charge 2 cells in series (maximum voltage configurable to 8.4v/8.6v/8.7v/8.8v through a resistor, or in 0.1v steps from 8.3v to 9v through i2c, and saves setting internally) and charges the batteries making the charge voltage also available to system output pin (if batteries are fully discharged, you'd get around 6.7v)  and when input is disconnected, the battery voltage is put on the system out pin.

For the water turbine, you would have to either use the 5v one or you'd have to use a step-down / buck regulator to convert the 12v to something within the 4v to 5.75v supported range.


or if you want something more fancy that supports a wider input voltage range, see MP2760 :

MP2760GVT-0000-Z  https://www.digikey.com/en/products/detail/monolithic-power-systems-inc/MP2760GVT-0000-Z/17142225

MP2760GVT-000A-Z  https://www.digikey.com/en/products/detail/monolithic-power-systems-inc/MP2760GVT-000A-Z/22119781

-000A means it factory defaults to 2 cells in series, but you can change the setting through i2c .  **** “-010A” is the factory default for 1-cell applications. “-030A” is the factory default for 3-cell applications. “-040A” is the factory default for 4-cell applications.

It's buck - boost driver , it can take 4v to 22v in, and can charge up to 4 cells in series, voltage configurable down to 3.6v per cell so it can also do LiFePO4