...I'm talking like when doing alittle cleaning in the garage, bike not running key in ACC with battery tender plugged in. Any strain on the elec system to be concerned with ?

 

Okay to switch to the farthest right position. I do

 

As long as it is on a battery tender you should be fine. I switch mine to AUX during rides for stops 15 minutes or less with no issues. I do this mainly so I don't lose the last satellite weather update and have to wait 15 minutes after starting again for an initial map update.

However, I put a small clock radio in my garage for just that purpose. It is a bit more comforting using the proper tool for the job

 

Plugged into the tender you should be fine.

 

MANNN its gonna blow the speakers out and then void the warranty and then just plain old melt down to a puddle of gue.

Sorry couldn't help myself...

Batman

 

Let's see, some approximations and guesstimations if I can remember that stuff...

Standard Battery Tender, 12v at 750mA = 9 Watts

Boom Box, stock, cranked = 25 Watts/channel = 50 Watts
At "normal" volumes, probably 20 watts? (a WAG, probably a lot less.)

Typical Harley battery w/o tender; say 15 Amp Hours at 12v = 180 Watts for an hour or about 3.5 hours with sound cranked; at least 9 hours at normal volumes?

Take 9 Watts off of the 20 with the tender helping, and you're up around what, 15 hours or so?

That's the audio power, add a touch for the screen. About the same for the regular non-boom-box radios, screens don't draw much, neither does the GPS circuit.

So have a ball with your tunes. Just leave the tender on when you're done. Or better, go for a ride, my favorite way of charging the battery.

Edit: I forgot that on some bikes/trikes the tour pak lights stay on; if they're LED, no biggie, another couple of watts. Not sure about any incandescent ones.

 

I have used the radio just as you suggest many times. There is an automatic shut off after some period of time, I wasn't paying attention to the clock so I'm not sure how long, seemed to be about an hour. It might have been more or less. I wasn't aware of the feature but it exists on my bike. After resetting the switch to OFF then back to ACC I had the radio on for about another half hour. Most of the time the radio was normal listening level, but occasionally I would crank it up for certain songs, then back down again when a commercial came on.

When finished with what I was doing I went for a ride. No problem starting up, there was plenty of power in the battery. The tender was not connected during the first time although I have connected it most other times since I have moved the bike to a more convenient location.