12V adapter for canon EOS 20D
A few years ago I bought a 12V power adapter for my EOS 300D camera from Astronomiser. I allowed me to use my camera for more than 20 hours with a 12V 7.2 Ah gel battery. It worked fine without a problem.
After a switch to an EOS 350D I couldn’t use it anymore because this camera type uses a different battery type. My 12V adapter was in a drawer for a year. Now I have an EOS20D and I can use the adapter again.
But it does not work well. After 1-3min the camera switches itself off with ERR99 and resets itself. I can use it again after removing and reinserting the adapter. For several nights I blamed a voltage drop of the power supply during use. I tested the voltage today during use and it is OK.
The EOS20D works without a problem with a normal battery and I don’t see the problem with my 300D.
I did notice that the EOS 20D has a higher power consumption than the 300D (during a long exposure: 420mA for the 20D versus 220mA with the 300D). Now I think the camera switches off because it is getting overheated by the adapter. I noticed Astronomiser changed the AST300DDC3CPro converter by adding a separate voltage converter box. I think this will be the solution for my problem.
[edit 26-feb]. My AST300DDC3CPro power converter for EOS 20D has arrived. The converter is in a seperate little box outside the camera. That should keep the camera cooler. I did a few long exposures of 1h or more. In the 3rd exposure I had another ERR99 again! I think I can blame the 7Ah 12V battery. I will recharge it again and will test if 10x1h is possible.
[edit 28-feb] During 6 hours I used my camera with the 12V adapter with exposures of 10-30min. Not a single problem. The amp glow is much less than with an in-camera battery. Up to 20min exposures I can hardly see amp-glow in the lower right corner. And even on 30min exposures the upper right amp-glow is absent.