If you ever do decide to use more power for things like heated gear, just remember to change the fuse back to whatever came with the charger during the winter months. It's a 3 amps for a reason. I could get into those reasons if you want.
What I do, is I electrical tape a 15A fuse to my battery tender. That way in the spring, I put the 15A fuse into the bikes pigtail fuse holder. Then I tape the 7.5A fuse to the tender.
Once winter comes and I go to hook it up, I put the 7.5A fuse back in and tape the 15A fuse to the tender.
I have a heated jacket and gloves so 7.5A is not enough.
just so I don't forget. I also agree with google. The gps doesn't draw shit. But if you want look at the back of the gps and it should say what it draws for current.