How to drain batteries out of camera?

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noimmunity

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Just after reading a thread about third party batteries, two of the four I bought started having recharge problems that I described in that thread but probably too late for anybody to read it.
Does anybody have a quick reliable way to fully drain M8 batteries?
 
The traditional way of doing this is to remove the batteries, connect a resistor across the battery terminals and let it discharge overnight. Do them individually. If you don't, and do them as a set, then one battery, with less charge than the others, will start reverse charging and will be killed.
 
noimmunity said:
Sounds great, but I have no idea how to do this. :eek: The terminals on the M8 battery are recessed.

Would putting a single battery in the charger, disconnected from a power source, work?
Click to expand...

You could hold the battery to your tongue (Natural Resister)... But doing this overnight is a bit inconvenient...

First go to your menu and turn the Auto Power Off to "OFF"... Then press play to look at a picture you have taken... Then just leave it sit... the battery will drain in an hour or two...
 
Last edited:
sfokevin said:
You could hold the battery to your tongue (Natural Resister)... But doing this overnight is a bit inconvenient...

First go to your menu and turn the Auto Power Off to "OFF"... Then press play to look at a picture you have taken... Then just leave it sit... the battery will drain in an hour or two...
Click to expand...

That is essentially what is in the manual for my wife's Sony camera.
 
FallisPhoto said:
The traditional way of doing this is to remove the batteries, connect a resistor across the battery terminals and let it discharge overnight.
Click to expand...

Ok but what ohm value resisitor to use? Too little resistance and I believe you'd short out the battery, and too much resistance and I believe you'd create a miniature heating element :eek:

I recall at least one battery charger I had (I think it was on a Metz battery pack) had the capability to discharge the battery before starting to charge it back up. I'm not sure if the M8 charger does that or not.
 
Jon & others,
PLEASE be careful when messing with Li-Ion batteries, as a total discharge of most types of Li batteries will ruin them (and possibly make them dangerous in some cases). I would NOT use a resistor to discharge a Li-ion battery (that was OK for NiCads, BUT NOT for any Lithium type battery) Here is a link for use and care of Li-Ion type batteries.
GlennB

http://powerelectronics.com/portabl..._care_extends-li-ion-battery-0425/index1.html
 
These days I leave them in-camera with the auto-power-off disabled.
But on one occassion I had serious problems recharging an old battery, so I left it in a fridge for two days and that seemed to ressurect its ability to recharge. Worth a try?
 
Thanks, Glenn. The link didn't work for me but a search on the linked site yielded some interesting results.
Among these the idea that partial discharge rather than full discharge extends battery life and that storing fully charged shortens life were the most interesting.

I've been draining my third party batteries in camera, but without turning on the LCD.
 
Jon,

I don't normally notice the battery level (just use it until the battery dies). But I have noticed the same thing when I was charging up a battery from half-dead two days ago. It showed as low when I put it in, and then full the next morning - it's been fine since.

Have you found the batteries to no be charged fully or just to show they are not charged fully?
 
Hey Kully,
I think what I am finding is that the battery is charged but the camera shows it as completely uncharged. It sounds to me like the "communication" problem between battery and camera that jaapv mentioned. An inconvenience, but not a deal-killer, so far at least.
Jon
 
had this happen too

had this happen too

the battery was fully charged and the camera thought it was empty. I then 'gave up' and used it for a whole day shooting and when the camera shut down finally i charged it and it showed up ok.
So what I am saying - even though the camera showed 'no bars' to begin with, it worked just like a fully charged ' three bar' battery ...
YMMV
H.
 
Interesting stuff. The M8.2 manual says the battery only reaches its full capacity after it has been fully charged and - by use in the camera- discharged again, 2 or 3 times. Discharge should be repeated every 25 cycles.
I find the easiest way to discharge the battery is have Auto Power OFF and then accidentally turn the camera on. Guaranteed dead when you pick up the camera to shoot.
 
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