Triumphrat

BerkBon · 05-21-2009, 03:00 PM

As suggested by Thruxtonian in a post on here, I attached a standard 12v female to the SAE 2 plug on a Battery Tender cable attached to my battery in order to power a GPS unit. When I plug the 12v GPS power cable into the 12v female, the little green power light on the cable comes on (understandable). If this cable isn't plugged into the GPS itself, how much power am I drawing (i.e., will my batter go dead)?

I'd like to have the cables all tucked in a zip tied, but only plugged into the GPS occasionally (the GPS is usually in my car). Will this setup work, or do I need some sort of additional power switch?

nimravus01 · 05-21-2009, 07:03 PM

So, it's just a cable extension, correct? If it's essentially a wire just hanging off your battery waiting for the GPS to be plugged in, then, no, you aren't drawing any current away from the battery.

BerkBon · 05-21-2009, 08:23 PM

Just an extention cable, but its the little green light that is now always on that worries me. Perhaps this is not a problem?

Thanks a bunch.

JimVonBaden · 05-21-2009, 09:19 PM

It depends, is the mount just a wire with a light, or is there a built in converter?

It sounds like some kind of converter. If so, you are drawing a fair bit of power. Even with just the light, you have a draw.

Jim

John_NH · 05-21-2009, 09:29 PM

If it just looks like a cable (no bulges in line or at the connector) it's probably just a small drain for an LED. I don't see why a power converter would be there. It's worth double checking with the manufacturer, but you should be able to go quite a while without draining the batter too much.

nimravus01 · 05-22-2009, 04:44 AM

If there is a LED (for whatever reason,) then it can eventually drain the battery. However, it will take some time for that to happen. You could figure it out by using the formula I=E/R. I being the current, E being the battery voltage, and R being the resistance of the LED. Then you could figure out how much current draw you are putting on the battery and decide if you charge it up enough between rides to keep it from being completely drained. A more real world approach would be to hook an ammeter to it and just read the current draw. Also, you can check the voltage on the cable with a voltmeter and verify there is not some sort of power transformer inline, (which is highly unlikely anyway since the GPS should be designed to run on a 12vdc car system.)

All that being said: I wouldn't leave the cable on there with a glowing light because it will drain the battery, (eventually.)

BerkBon · 05-22-2009, 09:57 AM

Thanks for the very detailed response! To be on the safe side, I'll unplug the cable when the GPS is not in use.