Dummy Battery NB4L (Ixus) - something's not right. - Hotwire! Hardware Mods, Accessories and Insights - CHDK Forum

Dummy Battery NB4L (Ixus) - something's not right.

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Dummy Battery NB4L (Ixus) - something's not right.
« on: 15 / September / 2010, 07:37:11 »
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Hi,

I'm planning to do some extended time lapses & decided I needed external power for my Ixus 70.
Clearly I wasn't very good with google, as I only found out about the Canon ACK-DC10 kit once I started to hit problems making my own.

I have made a dummy battery / fake battery and it works nicely, connecting to the + and - only & and leaving the T (thermistor) un-connected.

If I hook it up to my bench PSU, and dial in 3.7V, the camera powers up & works beautifully. So where's the problem?
If I look at the current consumption, with the camera powered up it's around .6A, which is quite a lot....
if I switch the camera off, it's still .34A (340mA) - that HAS to be bad - if it was draining that much with the power off, it'd flatten the battery in 2 hrs whilst switched off - and it doesn't.

So do I need to fake up the thermistor, or am I doing something else wrong? (maybe my contacts aren't quite aligned?)
Has anyone else seen anything similar - can anyone confirm that they've rigged up a dummy battery and that it does not draw current when the camera is powered off?

Thanks,

James. Manchester, UK

Re: Dummy Battery NB4L (Ixus) - something's not right.
« Reply #1 on: 15 / September / 2010, 13:18:35 »
Hmm,

OK a bit more info. Maybe my dummy battery is fine, but the camera isn't. I tried out what I had stated above - putting the battery in but not switching it on.
the battery gets hot & discharges good & quick.

This is a recent fault - and I guess I must have caused it by my poking around - possibly putting too high a voltage on the external PSU. Has anyone come across this before?

James

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Offline fudgey

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Re: Dummy Battery NB4L (Ixus) - something's not right.
« Reply #2 on: 15 / September / 2010, 14:09:08 »
What you describe could indeed be a result of excessive supply voltage damaging an overvoltage protection device, which now leaks quite a bit. Incorrect polarity has been known to cause damage too.

Re: Dummy Battery NB4L (Ixus) - something's not right.
« Reply #3 on: 15 / September / 2010, 17:11:23 »
Fudgey,

Hmm. Slap wrist & lesson learned.
Can I fix / replace it / short it out / remove the protection? what's it look like?
I've got a binocular microscope & a small bit for my soldering iron!
If not, I'm on the look out for a broken SD1000 I guess, so I can donate bits from mine to it or vice versa.

Thanks for the info

James


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Offline fudgey

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Re: Dummy Battery NB4L (Ixus) - something's not right.
« Reply #4 on: 16 / September / 2010, 15:26:53 »
Can I fix / replace it / short it out / remove the protection? what's it look like?
I've got a binocular microscope & a small bit for my soldering iron!

I wouldn't know, probably something rather small such as a 0805 or 0603 case but could be a semiconductor case or something else just as well, could look all cracked or burned of course, which would help identifying it. This part is highly likely very close to where the battery voltage enters the PCB. And if it is a parallel overvoltage protection device, removing it would solve your problem (but could make the camera prone to e.g. ESD damage from the battery terminals until you install a replacement).

There are numerous sites with photos of Canon cameras taken apart, looking at them should be helpful at least for hints of how to do it without damaging the camera more.

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Offline ahull

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Re: Dummy Battery NB4L (Ixus) - something's not right.
« Reply #5 on: 07 / April / 2011, 07:54:58 »
« Last Edit: 08 / May / 2011, 04:44:29 by ahull »

 

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