charging bl-5c | bl-6c

Michael Shiloh michael at openmoko.org
Fri Feb 15 22:59:51 CET 2008



Andy Green wrote:
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> Somebody in the thread at some point said:
> 
>> What does our original battery, i.e. the one without the coulomb
>> counter, speak on that middle pin?
> 
> Nothing, it's a dumb temperature sensor.

So it would certainly fail to respond to any HDQ conversation (er ice 
breaker if you'll pardon the horrible pun).


> 
> But the PMU that actually does the charging doesn't care what it is
> given, on the GTA02 it doesn't care about the temperature since the
> battery should take care of that.  So it should just charge the thing.

Oh!

> 
> What led us to understand these kinds of battery aren't getting charged?

I wonder if we had it backwards: Putting our battery in a phone that is 
designed for a BL-6C might result in our battery not being charged. In 
fact, the phone might refuse to switch on. My Nokia which uses a 5C says 
something like "battery error" and refuses to power up if I insert our 
battery.



By the way, it is my understanding that the coulomb counter is indeed a 
custom add-on for us, meaning that the standard BL-6C and other 
compatible batteries will in fact not work for us.

In GTA01, how did we read the temp sensor? Was the analog to digital 
converter (ADC) an additional component, or are there any ADCs on the 
Samsung SoC? If the former, then I presume we don't have that chip on 
GTA02, which means we can not safely charge a battery without the 
coulomb counter, because we can't measure the temperature.

Likewise if the battery is hooked up to a GPIO pin that does not have an 
ADC.

Are there other ways to protect against overheating a lithium polymer 
battery?

Michael





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