12v powered camera battery replacement

[petevasey]

Hi, all

For several years I had a modded Canon 350D, which for long sessions was powered by external 12 volts via a commercially available modified camera battery.  I eventually upgraded to a 700D, and decided to make my own 12 volt unit, using the case from a defunct battery.  For the transit of Mercury in 2016 I made one using a standard LM317T regulator inside the battery case. But it cut out at a point when I wasn't watching and I lost about 40 minutes of images.  It had acted up previously, but came back to life quickly.  This time I gave up and used ordinary batteries, fortunately I had two fully charged ones.

I reckoned the problem was overheating of the regulator - it was a very warm day, but I decided to look for something more efficient.  I've used 'buck voltage regulators' before and they do a good job, but most of them are too big to fit in the battery case.

Then I came across these, and ordered a couple to play with.  States '3 amps', but even at 2 amps got hot and I couldn't see an easy way of fitting a heat sink.  So I compared it with the LM317T unit, (which I'd fused at 1 amp quick blow, and it never blew when on the camera).  At 1 amp the 317T got uncomfortably hot very quickly, but the little unit just got slightly warm.  So I fitted it into the battery case (see pic below) and it worked fine.  After running all night on test taking a succession of 5 minute images, again it only got slightly warm. Still works after 3 years of occasional use.  I can't give detailed instructions on how to do this- different cameras have different batteries, and some might not have a slot for the 12 volt cable.  So a test meter needed to make sure the correct terminals are used and for setting the output voltage.  I recommend also fitting a 1 amp fuse in the supply line.  I accept no responsibility of course, but if anyone is handy with a soldering iron and fancies a go . . . .

Best of luck,

Peter

Edited May 9, 2019 by petevasey
Added link to Mercury transit and extra photo

[upahill]

A great little mod. I have a few of these left over and have been meaning to do it to get rid of the 'brick' on the mains lead im using now. Didnt even think of putting the converter inside the dummy battery!

 

[Thalestris24]

I did this one a while back - converted a canon mains battery eliminator to run from a 12v LiPo battery. No actual soldering required!  

I still use it sometimes - problem free  Can even use it for daytime photography as the battery is pretty light (300g) - you can carry the battery separately in a handbag or backpack with the long lead to the dummy battery/afapter . I think there are quite few similar diy canon psu variations about.

Louise
 

[Alien 13]

I have used various methods to power my Canon camera, the most recent being a 5V 10AH battery bank into a step up inverter that uses both of the battery banks 2A outputs and it actually runs well even with my power hungry camera (needs 1.5A to run).

Alan