Volts * Amps == Watts (ignoring resistance, etc)
12 * 32 = 384
Once you exceed that (384), you start draining your battery.
If it were me and I was worried, I'd install a voltmeter. If it goes below 12.6, you're draining your battery. Realtime notification, better than an event (dead battery) driven system.
Any recommendations for the type and emplacement of that voltmeter? Also, are you hooking it on the battery directly or is it fused on the existing box?
I must admit that I have not installed a voltmeter on a K-bike.
I did install one on my Triumph Tiger though. I installed,
http://www.aerostich.com/prevent-or-repair/electrical/batteries-chargers-and-monitors/led-battery-gauge.html on the dash. There are cheaper ones, but I was not disapointed with that one. If I was to install one on my RT it would probably be on the dash-pad across from the powerlet socket. Where you connect it to the electrical system is not very important, I chose a switched source on the Tiger.
I would not get too hung up on what style/type of voltmeter you install or where you wire it into the bike. If you're sharp about this stuff (I'm not) you can do the math and not worry about it. Or, if you know you've installed too many gizmos and want to pick and choose (because you know you can't run them all at once) the voltmeter is a good solution. The voltmeter will also let you know if your alternator/regulator stop working.
In British Columbia in mid-May at 0030, with the PIAA 910's on, the high-beams on, my electric vest on and the heated grips on, I was instantly informed that I was draining the battery. Turning off the heated grips solved the problem. Apparently they draw a lot of current. The lights assisted in dodging the moose. :yow
