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Old Aug 10, 2011, 06:01 AM
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Joined Apr 2011
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Originally Posted by Tom Frank View Post
Very clever of you to have figured this out! This is not something that most would want to attempt, but for those who might, can you summarize more clearly the advantage of doing this mod?
Advantage of the mod for all users:

- Can record with a standard mini USB charger connected.

Advantage of the mod for V2 users:

- Makes possible to charge during recording.

Originally Posted by Tom Frank View Post
I've done some long recordings with my external battery pack using the simple modified plug that comes with the car charger, and my internal battery stays charged as long as the external pack is still providing power. Ditto for the car charger. Other than slightly different LED confirmation, there's no other differences between V2 and V3 cameras that I've found.
As I wrote in my old posts (search them via all my posts in my profile), V2 has no charging circuit on pin 4. The external power is connected in parallel with battery! Looking at photos of V3 and seeing (probably) 3 additional Schottky diodes there, I think, that V3 has redesigned charging circuitry and it works there with both pin 1 and pin 4. That is why the LED works there onl pin 4 as well.

V2 behavior depends on the external voltage on pin 4:

- 4.4V and less (e. g. dedicated car "charger"): V2 depletes the battery until its voltage reaches external voltage minus ~0.2V, and then it starts to use external power. For example, external 4.2V car charger starts to power the camera when battery depletes to about 10% of its capacity. Low risk, only in case of totally depleted battery there is a risk of overcurrent.

- 4.4V to 4.7V: V2 charges the internal battery forever. High risk of fast degradation of the battery. (Some people really complain about short battery live here.)

- 4.7V and more: Emergency breaker on the battery terminal disconnects it from the power. No charging or discharging happens.

(Note that the dedicated AA emergency charger has no regulator. Depending on the duty, its voltage varies over the whole range above. Turning emergency charger LED off indicates activation of the emergency battery breaker, i. e. it always overcharges a bit.)

Originally Posted by Tom Frank View Post
I don't use a laptop with the camera when away from home, so the switching from recording mode to USB mode when an external charger is powering the camera is not something I (or most?) need. And at home, I could alternatively get a simple house voltage to 12V DC converter wall wart that accepts the car charger plug if I need continuous power while recording.

I'm not trying to diminish your accomplishment in deciphering the camera circuitry (!)... just trying to understand what it does that can't be done now with simpler alternatives. I'm obviously missing something, so please enlighten me!
Unmodified V2 is not capable to correctly charge while recording.

When I am in car, I plug the camera to one of standard mini USBs plug of my universal 5V car power supply. The camera records and it is fully charged when removed from the car. (With the dedicated car "charger", my V2 camera was able to record about 2 minutes after removing from the car.)

When I am at home, I can use the camera as a reader. (My previous simple mod just disabled USB modes, and I had to remove the card, put it to the reader, read and then put back to the camera.)
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