BQ24045: .

Nishant Jivani

Part Number: BQ24045
Other Parts Discussed in Thread: BQ24040

We used BQ24045 Charging IC for the charging of 3.7V 800mAh battery (min 3V - max 4.2V). But when the battery voltage is below 4.06V and put on the charging then the CHG status pin is not changing it's state, But charging is started at the half of the desired current. When the battery is above 4.06V and put on the charging then all the functionality working properly. So is their any condition in BQ24045 that causes this problem?

over 4 years ago

0 Nishant Jivani over 4 years ago

Prodigy 20 points

We use this BQ24045 Schematic configuration in our product.

0 Nick Brylski over 4 years ago in reply to Nishant Jivani

TI__Mastermind 19195 points

Hello Nishnt,

Can you share any waveforms comparing the two cases? Would be good to look at IN, OUT, TS voltages. The device goes into half charge when TS is in the low temperature region.

Thanks,

Nick

0 Nishant Jivani over 4 years ago in reply to Nick Brylski

Prodigy 20 points

Hello Nick,

Thanks for your response.

Here are voltages you ask for :

When battery voltage is below 4.06V and put on charging :
IN = 4.98V
OUT = 4.18V
TS = 0.5V

When battery voltage is above 4.06V and put on charging :
IN = 4.90V
OUT = 4.35V
TS = 0.5V

I am also trying to get waveforms, once I get that I will share with you.

I am working in the normal room temperature 25C-35C, so I don't think that low temperature is an issue.

0 Nick Brylski over 4 years ago in reply to Nishant Jivani

TI__Mastermind 19195 points

Hello Nishant,

If the battery voltage is 4.35V, this is where the device enters constant voltage mode and charge current is reduced until the termination current is reached.

BQ24045 is intended for 4.35V batteries, using this to charge a 4.2V battery can result in damage to the battery.

Thanks,

Nick

0 Nishant Jivani over 4 years ago in reply to Nick Brylski

Prodigy 20 points

Hello Nick,

Okay. So can we use BQ24040 IC for charging of 4.2V battery?

Thank you.

0 Nick Brylski over 4 years ago in reply to Nishant Jivani

TI__Mastermind 19195 points

That is correct.

Thanks,

Nick

0 Nishant Jivani over 4 years ago in reply to Nick Brylski

Prodigy 20 points

Hello Nick,

Our production is ongoing so it is difficult to change the IC at this time, So can you please look at below waveforms, so you might give other solution that why this is happening.

I also want to mention some points that

Our batteries have OVP (Over Voltage Protection) at 4.25V.
When I use new battery first time (i.e. first cycle of charging and discharging) at that time I also get the same problem.
Mostly I get the problem in between 3.5V to 4.06V battery voltages (Above 4.06V there is no issue detected)

IN Pin outputs :

IN Pin (Battery is below 4.06V) IN Pin (Battery is above 4.06V)

OUT Pin outputs :

OUT Pin (Battery is below 4.06V) OUT Pin (Battery is above 4.06V)

TS Pin Outputs :

TS Pin (Battery is above 4.06V)

Thanks.

0 Nick Brylski over 4 years ago in reply to Nishant Jivani

TI__Mastermind 19195 points

Hello Nishant,

It would be good to look at a current probe waveform. Also may want to open up the battery pack and probe voltages around the protector.

Best regards,

Nick

0 Nishant Jivani over 4 years ago in reply to Nick Brylski

Prodigy 20 points

Hello Nick,

I am testing from last 2 week with different scenario and I think I find the solution for this. As you can see in the previous waveform I get the continues fluctuation on the OUT Pin in between 3.9V to 4.35V.

Charging IC is giving random output, So I want to confirm that our IC is original from TI or not. So can you give any identification mark available on TI IC? I also attach our IC photo below so can you please confirm that this IC is original BQ24045DSQT or not?