DC-DC converter vampire current?

[kafka-cloud]

Hello,

I am on the verge of installing two front magicshine lamp through a DC-DC converter (ebikes.ca 12V). I am wondering if the DC-DC converter will suck energy if the headlight are not plugged? If there is a vampire current being drawn (with significance) I would have to mount the converter differently (i.e. anderson tap instead of fixed in the wiring on the battery.)

What are your thoughts

cheers

 

[ohzee]

I do something similar now for high power led's. I was told it would cause loss and resistance being in the path of my
batteries / motor. I did not worry about the dc-dc drawing power when not being used , but not really sure.

Glad you asked the question I am interested in what other people have to say.

 

[Sunder]

Put the switch before the converter, and it can't.

That said, there is a very small draw when there is power in one side, and an open circuit the other side. At least there is in mine. I don't know how many different types there are, and some might not.

 

[LI-ghtcycle]

Interesting question, I would think it's a safe bet that ANYTHING can and potentially will if it's not isolated from the main battery power switch.

This is why I have a main power switch at the battery of some form on all my builds, and then a second switch for the rest of the system.

I suppose you might wire lights between the battery switch and main power so you can have power to the lights with out having to power up the controller too, but I'd still have some form of switch or a plug as you have mentioned to isolate them when not in use.

I really like these switches:

http://www.harborfreight.com/heavy-duty-battery-cutoff-switch-66789.html

(I use an older style they don't sell anymore, but this is the one I would buy since they are still reasonably priced.)

 

[ZOMGVTEK]

Switch the power going into the DC-DC.

I'm using a motorcycle 'kill' switch to run my 24S LiPo into a 120VAC switching power supply. My Magicshine defaults to on when you feed it power, so there is 0 draw with it off, and when you flip the switch the light powers up. Since I'm switching the 24S side, the current is very low and the contact resistance is not a concern. It just needs to handle 100V, and the kill switches are designed to short spark, so they do the job well.