Battery charger Suggestion needed !

Rohith Gopalakrishna

Prodigy 170 points

Other Parts Discussed in Thread: BQ24133, LM25118

Could you please help us in finalizing a battery charger for the below mentioned project?

Some updates

Battery type and capacity finalized: 3cell Li-Ion , 3000mAh

Input supply 17 V.

over 9 years ago

0 Rachel Moore over 9 years ago

TI__Expert 3160 points

Rohith,

Do you need a standalone, or host controlled charger? What current do you want to charge at?

Please use the online part selector tool to help narrow your search: http://www.ti.com/lsds/ti/power-management/battery-charger-solutions-products.page#p404=Charger&p238max=17;40&p1152=2-4 Cells&p338=Li-Ion/Li-Polymer

Thanks,

Rachel

0 Jil Jose over 9 years ago in reply to Rachel Moore

Prodigy 90 points

Hi Rachel,
I am Jil Jose, working on the mentioned project.
We need a standalone charger for a 3000mAh 3-cell Li-Ion Battery. System consists of a 17V to 13V regulator which supplies current to both Logic circuit and the charger. When the logic circuit is ON current available to charge the battery is only 1A and and when the logic is off 1.5A can be supplied to the battery.

We have checked the product list of TI and "BQ24133" is found to be suitable and cheaper. Please give your suggestion about the chip with the given spec.

Regards,
Jil Jose

0 Rachel Moore over 9 years ago in reply to Jil Jose

TI__Expert 3160 points

Jil Jose,

The bq24133 sounds like a good match for your system. Please make sure you do any voltage step-down needed by your logic circuit after the input to the charger. To charge the battery to 12.6V, you will need a VIN of greater than 13V.

Thanks,

Rachel

0 Jil Jose over 9 years ago in reply to Rachel Moore

Prodigy 90 points

Hi Rachel,
Thanks for the reply. So what is the recommended input voltage supported by the charger to regulate 12.6V output? The battery is meant to supply a voltage almost near to the regulator output voltage. What would be the minimum voltage that can be configured on the regulator assuring the proper working of the charger.
Regards,
Jil Jose

0 Rachel Moore over 9 years ago in reply to Jil Jose

TI__Expert 3160 points

You system will need to be able to work over the range of the battery voltage. Fully charged will be at 12.6V, but it will drop down as the battery discharges. A VIN of as low as 15V should be sufficient.

You should look at putting a buck or buck/boost converter before your system to regulate your system voltage if you need to have a tighter range on your system voltage rail.

0 Jil Jose over 9 years ago in reply to Rachel Moore

Prodigy 90 points

So that raises some doubts. In user- guide of evaluation module "BQ24133EVM" the recommended supply voltage is 6-18V(noted in table 3) to set BAT voltage of 12.6V and the board is not seemed to contain any buck/boost regulator. How does the board manage this input voltage to regulate 12.6V ?

0 Jil Jose over 9 years ago in reply to Rachel Moore

Prodigy 90 points

In datasheet the maximum input operating voltage is 17V. Has the charger got enough margin to support input supply from the 17V adapter? If not, please suggest an IC charger that supports 17V to regulate 12.6V .

0 Jil Jose over 9 years ago in reply to Jil Jose

Prodigy 90 points

Gentle remainder...!!!

0 Rachel Moore over 9 years ago in reply to Jil Jose

TI__Expert 3160 points

Jil Jose,

The bq24133 is a buck only charger, The VIN should be greater than the battery regulation voltage to work properly. In your case with a 12.6 battery a VIN>=15V up to the maximum recommended supply voltage will work correctly.

Thanks,

Rachel

0 Jil Jose over 9 years ago in reply to Rachel Moore

Prodigy 90 points

Rachel,
OK. Thanks for the reply. But that didn't clear my doubt fully. I am planning to supply the output of 17V adapter to the charger(ie. maximum recommended voltage). Has the charger got enough margin to support the tolerance in the output voltage of the adapter?

0 Rachel Moore over 9 years ago in reply to Jil Jose

TI__Expert 3160 points

The absolute maximum rating is 20V on PVCC and the recommended operating condition is 17V maximum. A typical 17V adapter will be fine.

0 Jil Jose over 9 years ago in reply to Rachel Moore

Prodigy 90 points

Hi Rachel,

So we are planning the power supply system as shown in the block diagram. I would like to know about your opinion about the system.

Also please tell me about EOL of both ICs (BQ24133 and LM25118). We have to assure the availabily of the ICs on market at least for 5 years.

Regards,

Jil Jose

0 Rachel Moore over 9 years ago in reply to Jil Jose

TI__Expert 3160 points

Your block diagram season reasonable and we have no current plans for EOL of the bq24133 in the near future.

For questions regrading the LM25118, please post to the appropriate forum for the best support.

Thanks,

Rachel

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Battery charger Suggestion needed !