Good points.
Thankfully, in the last 3 cars in which I have carried a 12V accessory-powered tire pump, the accessory voltage was sufficient enough to have left over to crank the engine after inflating tires.
Everyone else I personally know runs the engine while using such inflators, contrary to paper instructions, but you know the attitude: “Ta h e ck with what the manual states - Live Free or Die!” lol
The power outlet inside the vehicle can only supply 10 to 15 amps, depending on the fuse size. The headlights draw more power and people think nothing of leaving the headlights on for 10 minutes; “they are automatic”.
If it’s a scenario where the key is in Accessory, headlights are on, and someone is airing up their tires with the 12V inflator, that could be a problem depending on the age of the vehicle and especially, age and condition of battery.
Didn’t @bing throw away a compressor?
I use a hand pump. 10 strokes adds a pound; I can do a stroke per second. It would probably take me longer to run the extension cord to run an electric. And I don’t run down the battery when I’m in the backwoods and have to deal with a punctured tire.
This one - Bell Air Attack:
Amazon.com : BELL Air Attack 450 High Volume Bicycle Pump : Sports & Outdoors
About 5 strokes per lb.
Since I check my pressures every two weeks, if I need to add air its only about 10-20 strokes.
Cordless or 110v
No bicycle pumps . . . In my experience, they typically teeter totter too much when pumping
Well I replaced my main one because it was getting old. I gave it to my HVAC guy and said it still works fine. I also have a pancake one that I bought for roofing at the cabin. Then I have a small $50 one that I hardly ever use except for blowing out the smoke and CO detectors on three floors.
I have air outlets piped all over the garage and also in the utility room but I should have piped an outlet on each floor. Pretty hard to do now. Tire pump? For kids.
Yeah, I unhid you just to see what you were saying after a couple months, figuring maybe you changed.
Still refuting my every word, as always.
Back on blocked, and yes, it was me who reported half a dozen of your refutations.
George, Old Days Rick: Instead of going into hiding, just report those who get on your nerves, and block them from view.
YOU are the one who needs to improve your social skills. You are the one who constantly needs to insult and “educate” the rest of us. You’re the one who constantly says everyone else is wrong, except you and @Old-Days-Rick
Just because I don’t agree with you about the bicycle pump . . . ?
whatever
There you go again, being petty and implying the rest of us are the ones with the problem
YOU are the one who constantly strikes a nerve with just about everybody else . . . and they’ve ALL told you so, in their own words
But you be you . . . keep trying to convince yourself we’re all wrong and only you and Rick are correct.
Wait a minute, Nevada just made a good point(s), if anything is killing the battery (other than a constant crank no start) after ONLY 5 minutes, then the OP has a battery issue and it needs replacing… Every battery has a reserve along with the CA and CCA rating, you should have enough reserve for your vehicle to be able to leave the head light on for 20-30 minutes, so either the OP has the wrong group battery or a bad battery, BMW’s can have 3-4 different group size of battery’s depending, so just because it is a BMW group battery, does not mean it is the correct group size and rating battery…
The air compressor can’t pull over 15 amps or it would blow the fuse, right?, no matter how big and bad it is… unless hooked to the battery itself…
I recommend having the battery tested, or just turn the lights on for 10-15 minutes then back off and see if it will still start right after…
MMmmm but, I take care of my parent’s cars too, also BMWs, same deal, have to turn the cars on to run the tire inflator.
No complaints yet! lol.
Power supply to the power outlet is off when the ignition is off. Ignition must be in the accessory or on position for power outlet use. Having the engine running may provide assurance the battery won’t discharge but then there is the fear of wearing out the engine. 5 minutes of idling per month will not make a difference.
My tire inflator is on a very long cord to the 12 volt accessory outlet on the dash. Works great. Draws little power.
Yep definitely doing that. What’s interesting with engine off and accessory on is the tire inflator sorta revs up its inflator motor then about half way to full level (you can tell by hearing how loud the motor is) it turns off. With the engine on it’s just fine.
You can stand on them. Or you can use a foot pump. I carry a foot pump in the truck, but it’s slower and the gauge doesn’t work. It stores more compactly and I can keep my hands warm when I use it.
Why?
I like your response
Thank you 
I guess it goes back to my depraved youth. I wanted a 1/4 inch manning bowman electric drill for my birthday. I dunno how old I was. It was the only power tool we had until the bank started giving them for $50 deposits some years later. No socket set except a sears breaker bar and sockets. Broke a few bolts. Didn’t get a ratchet until college. So I just haven’t been able to pass up tools and power tools like compressors, saws, planers, welders, sanders. Often can stop at one and need multiple. For the wife it’s shoes based on saddle shoes when she was young. I could get by on one pair of shoes and boots that would last 50 years, not 100 pair. But tools I can’t stop.
The instruction sheet with my Slime digital tire inflator specifically states Accessory position, engine off.
So why would I not follow those directions?
(Call me “holier than thou s n o b” for simply following instructions)