BQ2419x and LiFePo4

Lauri Jamsa

Other Parts Discussed in Thread: BQ24190, BQ24105, BQ24192, BQ24630

TI just released BQ24190/2/2I/3/6 battery charger ICs. I'm planning to use BQ24190, but I would like to support also LiFePo4 cells.

There is this one document describing how to charge LiFePo4 cells using Li-ion/LiPo charger IC (BQ24105/25), but is it also possible using BQ2419x? Charging current curve might not be 100% correct for the lower voltage cells, but is it possible?

http://www.ti.com.cn/cn/lit/an/slua443/slua443.pdf

over 12 years ago

0 Lauri Jamsa over 12 years ago

Prodigy 40 points

Any ideas?

0 Charles Mauney over 12 years ago in reply to Lauri Jamsa

TI__Mastermind 31120 points

Yes, the bq24192 is very flexible and can be set up to charge a single cell LiFePO4.....One can set the regulation voltage, charge current and precharge current.

The precharge can only be set down to 2.8V, but there is essentially no capacity below 3.2V so it would not take very long in precharge to get up to 2.8V where fast charge would be set.

0 Lauri Jamsa over 12 years ago in reply to Charles Mauney

Prodigy 40 points

Thank you Charles! I would like to use BQ24190, but I think the parameters and possibilities are the same for the both ICs?

Do you think if it's possible that TI could publish an application note about charging LiFePo4 cells using BQ2419x charger ICs?

0 Charles Mauney over 12 years ago in reply to Lauri Jamsa

TI__Mastermind 31120 points

It may be a good idea, but probably is not a high priority.

Refer to the bq24630 data sheet for any ideas.

One really does not do much different for LiFePO4 other than set the regulation voltage at 3.6V and it can take at least 5C charge rate.

The best thing about LiFePO4 is that it is much safer than LiCoO2......Regulation can be way off (as high as 4V) and it is very low impedance so it can take tons of current.

0 Lauri Jamsa over 12 years ago in reply to Charles Mauney

Prodigy 40 points

Thanks again :-)

Is there any application notes or a reference design about using Li-ion/LiPo/LiFePo4 cells directly with the proper charger IC? I mean bare cells without integrated over-current/over-discharge/short-circuit protection circuitry?

Power management

Power management forum

BQ2419x and LiFePo4