Will leaving the trunk open drain the battery?

A month after I bought my 2021 CX-5 and was detailing the car, leaving the trunk open. After about an hour or so, I heard a couple of beeps and shortly thereafter, when I went to start it up, battery was dead. Dealer said that this was a function of the power liftgate. Dunno, but I do know that I won't leave the trunk open for any more than I have to.
That may account for the differences in experiences in these posts where the power liftgate continues to draw current despite the battery saver whereas the manual liftgate does not. This is the kind of stuff than can have undocumented differences from year to year or trim to trim so the only real answer is in testing.

Short of an extended test in a garage, leaving the liftgate open for several hours while being prepared to jump it, to be safe the answer is to disconnect the battery when tailgating or whatnot.

When I disconnected my battery for two months last winter I was surprised to find the radio station presets were still there, evidently stored in some non-volatile memory. I also detected no difference in performance, so it appears performance adjustment codes (or should I say "settings" for the benefit of one banned poster ;)) were likewise retained in non-volatile memory in my vehicle in any case.
 
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Right? Never wanted that feature. I can count on one hand the # of times it would have helped me since Nov 2016.
I agree, but it's a personal preference.

Unless it's one of those systems where you can wave a foot under the bumper to raise the liftgate (not a good idea for people with balance issues) you still need a free hand to fish out the fob. I suppose if one has bad rotator cuffs or some other infirmity whereby raising an arm to close the thing causes pain its a valuable feature. Or perhaps a very short person may not be able to reach the open gate especially if the lift height setting has to accommodate multiple users. However, I suspect there is no shortage of able bodied, reasonably tall car buyers for whom more is better when it comes to gadgetry.

Tangentially, I have the same attitude toward sun roofs. I've owned a convertible and a vehicle with a sun roof. The novelty wore off pretty quickly. I prefer the climate controlled environment without the sun beating on my head or wind blowing around the cabin. Different strokes. I could go on--power folding mirrors, GPS cards, heads-up display windshields. My 7 year old $125 Garmin with lifetime free map updates sitting on the dash serves the purpose of the latter two while my garage is wide enough that the power folding mirrors offer no utility. If I had to fold the mirrors to squeeze into a parking spot I wouldn't want that spot anyway.

The less stuff in which I find little or no utility the better. It's just more stuff that can break, or you get unintended consequences such as power liftgates causing dead batteries or inadvertently left open. If one of these things does break then you're faced with the choice of fixing it or depreciating the vehicle when selling. If you fix something you don't need they got you coming and going--the price you paid for it and the cost to fix it. In some cases you have no choice--heads up display windshields or busted sunroof glass (rare) ain't cheap.

Like I said, different strokes. But before I get off my soapbox it's worth evaluating the tradeoffs as one moves up the trim scale--the things you want or need may come with more headaches with the things you don't. More is not necessarily better.
 
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On a related subject, some folks have expressed the opinion that the fob buttons would be better placed on the face of the fob rather than the edge. Be careful what you wish for. My Sienna's non-smart fob with buttons on the face inadvertently locks / unlocks far more often than the CX-5.

There was a video posted a while back showing a guy who took the guts out of the smart key and installing them in another case with buttons on the face. When done, he demonstrated the buttons but not the smart key functions. You would have wanted him to demonstrate the door push buttons to show they were still working and whether he could still start the vehicle! Would you want to try that hack unless you were willing to sacrifice a $100+ fob in the experiment? I think not. And if it did work, you may be worse off than where you started as in the case of my Sienna.
 
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Right? Never wanted that feature. I can count on one hand the # of times it would have helped me since Nov 2016.

I agree, for me this option is useless and only adds to the complexity of the car. Another thing to break.
 
I solved the random open liftgate by taking the keyfob battery replacement one step further and cutting the plastic rod off the back of the open liftgate button so it is not functional. I find it easier to press the button on the liftgate handle rather than the keyfob anyway...
 
I solved the random open liftgate by taking the keyfob battery replacement one step further and cutting the plastic rod off the back of the open liftgate button so it is not functional. I find it easier to press the button on the liftgate handle rather than the keyfob anyway...
Maybe a good compromise would be to shave that piece so that you need a much firmer push to open it. That way you still have the functionality without the likelihood of false presses in your pocket (?)
 
Yeah what sucks is it is a mazda design problem with the keyfob.
The liftgate isn't the problem the keyfob is.
Never had keyfob liftgate problems with fords or nissan. Even the Jeep rental I had, didnt have the keyfob accidently trigger liftgate.
One cheapo thing you might try.. Get one of those silicone fob covers off of amazon.. Once you stretch it over the fob, test it to see if the presence of the cover is enough to help your issue.. if not, you could fold a thin piece of plastic (like the clear bubble pack plastic on so many product packages) and tape it on the fob over the tailgate button. Once you put the fob cover back on, you wont see it.. and the button will still be usable, although it will be harder to push.. I know this is very hackish.. but I had to go this route for a couple streaming devices I have where there are dedicated buttons for prime, netflix etc.. I was constantly touching one of those buttons (barely).. and my active program would get interrupted, the app would change etc. causing me to get back in and start it up again.

my $.02
 
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