Toney, you are riding a Versys 1000 now, correct?
If one plugs in all 4 of those heated garments into a KLR650 and turn up high, the KLR battery will not start the bike after an hour of riding! Not a strong enough charging system.
And one might cause the alternator windings to short circuit in even a few attempts. Alternators & generators will over-heat when loaded to 100% capacity for too long / too often.
Well.... Not to argue the point,,, maybe I'm lucky but I ran all that heated stuff on both of my KLR's (09 & 14). I did swap out most "always on" bulbs with LED's on the KLR's. Other than that, the only "help" the charging system got was a 14 tooth sprocket and that was a byproduct of gearing it down a bit for the trail. I never had an issue with a low battery, dim lights or slow cranking. Ever.
As you know the headlight is the killer on the KLR. The 2014 had a factory battery & the 09 had a Autozone battery. I used (and still do use) a Gerbing brand (two output) thermostat. It has two knobs that control how hot it gets by pulsing the current on and off. Most of the time (when it's below 50F) the jacket liner is on 100 percent of the time. I only wear a lightweight riding jacket over it, however I do have to turn down the socks to keep from slow cooking my feet in my boots. The trick is to put on a lightweight shirt, then the heated liner and cover with an insulated tight fitting jacket that blocks the wind. Toasty!
All my heated stuff must be over 10 years old. It's been with me on 2 Goldwings, 2 KLR's and now the Versys 1000. The only problem I ever had (years ago) was with one sock that Gerbing fixed for free. When I first got the 09 KLR, I worried about power too so I installed a device that would disconnect the thermostat if the voltage went below 10 volts. I don't think it ever "tripped". I didn't even install that on the 2014.
Maybe if you were creeping around the trail at really low rev's, it could be an issue but at low speeds/rpm, you'll be turning the heat off pretty quick anyway.
Once you ride with heat, that's it, you're done. You'll always have heated gear!
DISCLAIMER: Gerbing no longer makes the gear I have and were bought out since I purchased my stuff so I can't say the new stuff is as good as my stuff. I've read they even have Bluetooth controls now. I can't understand why. My knobs are not that hard to turn. Something to impress the chicks with maybe? Who knows!