Canon 700D battery drain with 2 x convertor

Andyglider wrote:

I am having a battery drain issue my Canon 700D when used with a 2 x convertor. If I use it with my canon 70-300mm lens there is no problem and the lens can be left on for months with no battery drain. When I then add a Viltrox C-AF 2 x teleplus converter the battery will drain overnight with the camera switched off. All very odd as I assumed when the camera was turned off there was no supply to anything. Clearly the 2 x convertor is the problem but I don't know why. Convertor does work but I cant' leave it on the camera. Is it because it's a cheapish convertor?

Modern electronic power switches work differently than the typical in-line disconnect switches like you'd see in your house for lights and lamps and such.

Electronic switches such as those found in most computers, electronics, TVs, phones, etc never really disconnect the power feed completely. There's always circuitry that remains powered up, waiting for that turn-ON "signal" to tell it to wake everything else up!

These circuits continuously use a bit of power (to some degree or another) which is known as "parasitic drain." This (always powered) state is also what makes your electronic equipment very susceptible to power surges and lightning hits! (Protect your equipment accordingly).

In your case, it's not that designed-in parasitic drain that's causing the power issues though. There must be some bad (or poorly designed) circuitry in the lens adapter that is creating a pathway to ground, thus draining your entire battery overnight. Or it may be powering up your Image Stabilization circuit continuously (even when the camera is "off"). Something like that.

I wouldn't connect that particular adapter again (you've already done the basic troubleshooting, kudos to that). Under-voltage is never a good thing for electronics.

There are a number of good TCs on the market (even genuine Canons! ). I have a Tamron 1.4x (the ~ $100 one) that has worked flawlessly for me on a number of bodies. Keep in mind though that you won't get AF (with your combo) with any of them.

Well, good luck to you. Happy shooting!

R2