BQ24230: 2S battery charging

Ken Diep

Part Number: BQ24230
Other Parts Discussed in Thread: BQ25886, BQ25155, , BQ25887

Hello,

I have a 2s 7.4V 180mAh battery. I have come up with two ways of charging it

1. Using a switch to connect both cells in parallel and charging them using a 1s charger (similar to this guy https://42bots.com/resources/a-circuit-to-use-2-single-cell-li-po-li-on-batteries-in-series-and-charge-them-in-parallel/)

2. Using a 2s USB boost charging IC such as the BQ25886

Could anyone tell me which would be the more efficient approach out of these two?

Many thanks

Ken

over 5 years ago

0 Ken Diep over 5 years ago

Prodigy 80 points

I realised that the first link is for using two SEPARATE LiPo cells so not applicable to my battery.

Still, is there any way to balance charge a 2s battery using USB?

0 Anthony P Pham over 5 years ago

TI__Mastermind 23410 points

Hi Ken,

I'd recommend going with a boost charger if you're going to choose a standalone charger. If you were to split the battery to 3.7V 1S 2P, the only linear chargers that could charger it are I2C controlled such as the BQ25155. Otherwise, most standalone linear chargers charge 1S batteries to VBAT_REG 4.2V typically.

Either way, I'd recommend the boost charger as switching is generally more efficient than linear chargers such as the BQ24230

0 Anthony P Pham over 5 years ago in reply to Anthony P Pham

TI__Mastermind 23410 points

Hi Ken,

The BQ25887 is an I2C version of the BQ25886 that will provide cell balancing.

0 Ken Diep over 5 years ago in reply to Anthony P Pham

Prodigy 80 points

I think that will suit my needs quite well! Is there any clear advantages that a standalone IC would offer over I2C control?

0 Anthony P Pham over 5 years ago in reply to Ken Diep

TI__Mastermind 23410 points

Hi Ken,

I would say the clearest advantage for a standalone is that it is configurable in some settings through resistors while the I2C device will typically need a host device such as a micro-controller to configure the same settings or more.

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BQ24230: 2S battery charging