My Gta02s wont charge
steve at openmoko.com
Wed Jun 25 19:21:13 CEST 2008
Micheal, Friday is looking like a better day for me
From: Werner Almesberger [mailto:werner at openmoko.org]
Sent: Tuesday, June 24, 2008 9:17 PM
Cc: 'Andy Green'; 'Joerg Reisenweber'; openmoko-kernel at lists.openmoko.org;
'Sean McNeil'; 'Michael Shiloh'
Subject: Re: My Gta02s wont charge
> For completeness let's review the steps you want michale and I to go
1) Measure the voltage across the terminals of the "dead" battery
and post the result. Expected result: either no measurable
voltage, or somewhere in the 2.4V-3.6V range.
2) If the voltage measured in 1) was very low (<1V), take a power
supply in the 4V-5V range (*) and connect briefly (~1s) to the
"dead" battery, such that + goes to + and - goes to -.
Then measure the battery voltage again.
(*) Examples, in increasing degree of fanciness:
- one of those ancient 4.5V batteries, e.g., the leftmost in
- some wall adapter that emits 4-5V DC
- another Neo battery (charged)
- lab power supply, e.g.,
If the voltage measured in 1) was significantly above zero or 2) doesn't
help, you may consider charging it in an external charger or from a lab
power supply (if Michael has any of these).
For the latter, set the voltage limit to 4.2V, the current limit to 0.8A,
connect + to + and - to -, and enjoy some beers while waiting.
You should see the voltage rise to 4.2V with the current constantly at 0.8A,
and then the voltage remains at 4.2V while the current drops towards 0A.
Your battery is charged when the current drops below 0.1A.
Please be careful not exceed the 4.2V. A bit less (e.g., 4.0V) is okay, but
will charge the battery only partially.
If also external charging doesn't restore the battery to a working
condition, then it may have suffered some permanent damage.
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