I have cteks for all may cars and motorcycles and they are always connected at least overnight, even may daily runaround as many short trips means the battery never gets to full capacity so an overnight on the ctek does the trick. Remember the ctek actually goes though a significant process of checking the battery's internal condition and then applies a charging and maintenance programme that is bespoke to optimise that particular battery.
I also use the Noco jump start packs and have found these to be bar far the best - keep your preferred one in your amazon watch list until they have a deal on which they often do.
I have used an Antigravity Battery (as mentioned here in an earlier post) on my BMW motorcycle to reduce weight and size. My experience was not particularly positive - it did, without question need to be permanently on a specific Optimate charger designed or Li-on cells and then despite this after about 2-3 years it just completely failed and could not be recovered. Very expensive for the time it lasted and I have gone back to and stick with the much heavier lead acid batteries now on a ctek and not every had a single issue since.
As has already been said and we all know already mechanical things like regular and frequent use so it'd be far better (for our cars anyway) if we all had just the one vehcile -
