BQ24650: Battery Charger

Mauricio Correa

Part Number: BQ24650
Other Parts Discussed in Thread: BQ25756, BQ34Z110, BQ34Z100-R2, BQ34Z100EVM, BQ34110, BQ34Z100-G1, BQ34Z100, BQSTUDIO, EV2400

Tool/software:

I think the IC BQ24650 doesn't charge two lead-acid batteries in series because we need 29.4Vtop. And then my question is:
In a system with an AC/DC source and two 12V/26Ah lead-acid batteries in series, as in the circuit shown below, we need to charge the batteries in series and monitor the system and the batteries' state of charge (SOC).
Items to check:
Voltage and current of the power supply, voltage and current of the batteries (of the set) during charging and discharging, and state of charge (SOC).
Question:
Is there a single IC that can do both functions (A and B), i.e. charge and monitor? What would it be? Or do you need two ICs for these functions (A and B), i.e. charging and monitoring? And what would these ICs be?
Thanks in advance for your reply.

5 months ago

+1 Christian Moyer 5 months ago

TI__Mastermind 19760 points

Hello Mauricio,

Mauricio Correa said:
Is there a single IC that can do both functions (A and B), i.e. charge and monitor? What would it be? Or do you need two ICs for these functions (A and B), i.e.

No, We do not have a single IC that can do both.

Mauricio Correa said:
And what would these ICs be?

I do not support battery monitors, so I can not give a recommendation on which one to choose.

For the battery charger I recommend BQ25756. I also recommend using this appnote for further information on how to use this charger for lead acid:https://www.ti.com/lit/pdf/slua992

We are also coming out with a dedicated lead-acid battery charger in the next few months, that is similar the BQ25756.

Best Regards,

Chrisian.

0 Mauricio Correa 5 months ago in reply to Christian Moyer

Prodigy 70 points

Thank you Christian. The BQ24650 has been solved with your recommendation.
However, to monitor the battery of two 12V lead-acid batteries (6 cells x 2) connected in series, would it be possible to use the BQ34Z110? It can monitor the batteries (12 cells) when there is no AC and the system is powered from the battery (SOC).
I look forward to your reply. Thank you very much.

0 Christian Moyer 5 months ago in reply to Mauricio Correa

TI__Mastermind 19760 points

Hello Mauricio,

I do not support the BQ34Z110, I am assigning this to the team that supports this part.

Best Regards,

Christian.

0 Mauricio Correa 5 months ago in reply to Christian Moyer

Prodigy 70 points

Thanks.

0 Diego 5 months ago in reply to Mauricio Correa

TI__Mastermind 18560 points

Hi,

I recommend using BQ34z100-R2 over BQ34z110 for your application.

Regards,

Evan

0 Mauricio Correa 5 months ago in reply to Diego

Prodigy 70 points

Thanks for your time, Evan.
However, having looked at the datasheets, the BQ34Z100-R2 does not mention lead acid batteries. However, the datasheet for the BQ34Z110 says it is for lead acid batteries. Wouldn't that be the BQ34Z110?
Remember that we are using two 12V lead-acid batteries in series (6 cells x 2 packs).
Thanks in advance for your reply.

Maurício

0 Diego 5 months ago in reply to Mauricio Correa

TI__Mastermind 18560 points

Hi,

Not sure why lead acid is not listed on the datasheet. BQ34z100-R2 supports lead acid. Lead acid is listed on the product folder.

Thanks,

Evan

0 Mauricio Correa 5 months ago in reply to Diego

Prodigy 70 points

OK Evan.
More questions:
Can the BQ34Z100EVM connect two 12V lead-acid batteries in series?
Is the full IC part number BQ34Z100PWR-R2 or BQ34100PW-G1?
The EVM bill of materials lists BQ34100PW-G1. If it's R2, do I need to buy the BQ34Z100PWR-R2 separately?
Thank you very much.
Maurício.

0 Diego 5 months ago in reply to Mauricio Correa

TI__Mastermind 18560 points

Hi Mauricio,

Yes, the BQ34z100-R2 and BQ34110 are both top of stack gauges.

Bq34z100, BQ34z100-G1, and BQ34z100-R2 all utilize the same hardware, the only difference is the FW, any version of the FW can be flashed onto any BQ34z100.

I recommend using R2 FW and if you purchase the EVM with G1 FW you will be able to update it to R2 FW.

Regards,

Evan

0 Mauricio Correa 5 months ago in reply to Diego

Prodigy 70 points

Hi Evan;
I understand that I can change the FW (to R2 FW).
But if I buy the EVM, can I specify the same R2 IC that I'll be using in the project? In principle it would be the BQ34Z100PWR-R2.
If not, I would switch to the BQ34Z100PWR-G1 in the project. Is this correct?
Or if the difference between the chips is just the firmware, how do I update it to R2 FW? Because I didn't see in the documentation how to do it.
Regards,
Mauricio

+1 Diego 5 months ago in reply to Mauricio Correa

TI__Mastermind 18560 points

Hi Mauricio,

I do not think you can specify which FW is loaded onto the EVM. The ICs are the same for all versions.

Yes, the only difference is the FW.

So, to flash new FW onto your device, you need to flash the .srec file onto the device. This can be done over i2c but is much easier using an EV2400 and BQstudio, using the programming tab.

FW available here : BQ34Z100-DEVICE-FW Firmware | TI.com

2.02.31 - R2

Regards,

Evan

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BQ24650: Battery Charger