Interesting...I'm wondering if the low battery Fob warning is displaying from the last time the Fob was close. It may keep displaying it until the Fob is brought close again (with a fresh battery). I also don't use the fobs and keep them in a Farady pouch with a couple of extra batteries.
I don't know about why you are losing charge but I would be cautious about exclusively using the mobile key. Phones have been known to fail, get dropped and broken, etc. If you have it on a watch as well, then you already have a backup.
I also started storing my the fobs in a faraday pouch as an experiment to preserve the battery The batteries went flat in a matter of months before that, so far so good in the pouch. I'm an exclusive phone key user and carry the card key for back up access.
I also started storing my the fobs in a faraday pouch as an experiment to preserve the battery The batteries went flat in a matter of months before that, so far so good in the pouch. I'm an exclusive phone key user and carry the card key for back up access.
I don't have them in a Faraday pouch but might start. I also always have my card key as my backup if the phone fails, which it's done a couple of times!