BQ25798: Solar MPPT controller & battery charging

Gary Andrew

Part Number: BQ25798
Other Parts Discussed in Thread: BQ76942, , , BQ76942EVM, TPS61200

Hello,

I'm looking for confirmation & advice on using BQ25798 & BQ76942 to manage power flow between a 2S2P solar input delivering 4.5--5.5V at <1A into the BQ25798 and charging a 4S or larger set of batteries via the BQ76942. Out of the BQ25798's SYS output, we'll deliver an expected 12--15V to a PMIC.

Given the newness of these two BQ components, there's not much information yet available. I'm hoping for some basic confirmation as to if this is likely to be a workable solution and if not, for suggestions on alternatives.

Thank you!

over 4 years ago

0 Jeff F over 4 years ago

TI__Guru**** 167196 points

Hi Gary,

We have data on using these 2 ICs together. Usually, the monitor/balancers and chargers are independent of each other. You should be able to connect BQ76942EVM and BQ25798EVM and test without having to make a new PCB.

Regards,

Jeff

0 Gary Andrew over 4 years ago in reply to Jeff F

Prodigy 50 points

Thank you, Jeff.

Can you tell me if TI has a 2--5.5V 0.5--1A input MPPT controller more intended to feed a 4--6S battery charge balancer? Ideally, I would like to have an MPPT controller dedicated to each channel of small solar panels, all feeding into the battery charger balancer.

Thanks again,

Gary

+1 Jeff F over 4 years ago in reply to Gary Andrew

TI__Guru**** 167196 points

Hi Gary,

I am not aware of such a device or reference redesign. The 2V minimum input voltage at that power level is difficult to handle and the TI charger portfolio currently does not include chargers for up to 6S LiIon batteries. You might try the TPS61200 with opamp to implement for MPPT (https://www.ti.com/lit/pdf/slva345) to get 5V power and then add 6S charger reference design from https://www.ti.com/reference-designs/index.html.

Regards,

Jeff

0 Gary Andrew over 4 years ago in reply to Jeff F

Prodigy 50 points

Thank you again, Jeff.

I'll continue investigating both alternatives.

Gary Andrew

Power management

Power management forum

BQ25798: Solar MPPT controller & battery charging