With cornie keg CO2 chargers, how do you keep the CO2 in them from just being absorbed into the beer in the keg? This is probably a dumb question, but it seems like it would be easy with a CO2 tank and regulator, but I’m not completely sure how the chargers work. How often do you have to inject CO2 gas? Sorry for the newbie questions. I’ve just started kegging. At least I do know that you can’t charge a tank with cartridges 
With the injectors, there is a trigger. When pulled, the trigger opens a valve to allow co2 into the keg. When not pulled, the valve closes and no co2 can enter the keg.
How often to you have to pull the trigger? Hard to say exactly, but I would say every 1-2 beers. It depends on how much co2 you inject when you pull the trigger. You can hold the trigger down and inject a lot of pressure if you want to.
I’ve used one a few times, you’re kind of planning on just pouring a lot of beers. When do you pull it again? When you get frustrated your beer isn’t full yet. One of the mini regulators is probably a better option, but the nice thing with the charger is you can lay it flat along the top of the keg (hopefully protected by the keg handles, etc. I’d watch out if you’re using a picnic tap, you can definitely over pressurize and start gushing beer out without opening the picnic tap.
Is the picnic tap just not strong enough to handle the pressure?
Keg chargers are great for taking kegs on the go and serving them at a party/tailgating/cookout/etc. They aren’t for carbonating beer or extended use. The cartridges hold up to several hours of serving, but will run themselves empty beyond that.
As far as regulators go, if you need any kind of precision with your pressure, then keg chargers aren’t what you’re looking for. They’re really just meant for a portable, short-term serving solution.
Makes sense! Thanks 