USB LiIon/LiPoly charger - v1.2

[7600onair]

Looking at this charger with a 110mah/3.7V lithium polymer battery, is 100ma charging current low enough?

Where is the resistor hole and what value is required for 100mah charging?

Thanks.

[adafruit_support_bill]

The programming resistor goes in the holes labeled "PROG". A 10K resistor will give you 100mA. (you need to remove the existing SMT resistor in that location).

You will have to check the manufacturer's recommendations for charge rates on that battery. 100mA would be typical for a LiPo cell that size.

[7600onair]

Thank you for the response. I hope a 1C charging current works ok.

Unfortunately the Chinese battery datasheet, in typical fashion, is very hard to read.

[peppelinux]

Hi,

I'm using USB LiIon/LiPoly charger - v1.2 for 3600mAh, 3.7Volts, liion battery.
I plugged a 5V, 700mA, solar panel in usb connector, the battery, leaving load plug empty for few hours.

After, when I plugged off the charger, I noticied that the battery level wasn't changed.
So I substitute the solar panel with a Benchtop power supply, using 5V.
Leds lights on, the benchtop amperometer remains near 0.

If I plug a load, using an AVR board, the benchtop amperometer signs 20mA.

Could it be defected ?
Am I wrong on some step ?

[adafruit_support_bill]

What voltage do you measure across the battery terminals?

[peppelinux]

with battery plugged I measure 3.68V
without it I measure 4.20V.

[adafruit_support_bill]

without it I measure 4.20V.

Are you measuring that on the charger or the battery?
What do you measure on the battery when it is disconnected from the charger?

[peppelinux]

when it is disconnected from the charger I measure 3.68V.
So the battery is 3.68V.

If I measure the charger, without battery and load, I got 4.20V.

[adafruit_support_bill]

Hmmm. 4.2v is the correct output voltage for the charger. And 3.68v indicates that your battery has at least a partial charge.

So I substitute the solar panel with a Benchtop power supply, using 5V.
Leds lights on, the benchtop amperometer remains near 0.

How near to 0? And how long did you leave it connected? The charge controller does not start out at the maximum charge current. It goes through a preconditioning stage before ramping up for the fast charge.

If I plug a load, using an AVR board, the benchtop amperometer signs 20mA.

That sounds like the 'load-sharing' circuit diverting input power directly to the load.

[peppelinux]

I left the charger on benchtop power for about 3 hours.

How to resolve this problem?
It's defected ?

How could it get damaged ?

[adafruit_support_bill]

So the output voltage is right, but it never ramps up to fast charge mode. Can you post a photo of the front of the board?

[peppelinux]

Yes, soon as I can.
If I increment voltage, from 5v to 6v I can see the ammeter signs more intensity.
So I can think that a very efficient charge is done with a voltage of 6v.

In 6V the intensity is about 350mA.

[peppelinux]

Here's the photo.

http://img27.imageshack.us/img27/6221/2 ... 112954.jpg

The resistor was desoldered and poles short circuited for charge maximization... But battery voltage is 3.68v and charge remains at 200mA.

I ordered a lipo charger 5-12V with other items, the shipping is taking long time, I hope that you'll help me understand this doubt before the other charger cames to me.
I need a very efficient charger for a WSN with high consuption.
And if all will be right I'll do a order with a lot of items, I hope and I think you too.

thanks,
g

[adafruit_support_bill]

Sounds like the charge controller chip is not working properly on your board. Contact support@adafruit.com with a link to this thread and ask for a replacement charger.

[peppelinux]

20 Feb 2013 I sent e-mail to support@adafruit.com.
No reply yet.

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