In many of the reviews I've read on the Kymco AK 550 there was mention how this scooter seemed to drain the battery rather quickly. Just recently I watched a video for Bike Trips from 2018 where the owner had his heated grips replaced with the (then) new and improved version. While this warranty service was being done his dealer also replaced a few other things under warranty and updated the firmware for the scooter electrical boxes. One item that was mentioned in particular was that the TPMS was "fixed" with the update that turned that system off when the bike was off. IOW, TPMS was no longer always on... draining the battery. There are a few other electrical systems that can cause phantom battery loads that will run down the battery. One is the Welcome screen function. It essentially makes the Noodoe screen on the scooter glow on and off a few times when you are close. The bike BT has to constantly sense or look for a BT connection with your phone for this option to work. This is one of the phantom loads on the battery. I turned that option off. You have to open the Noodoe app on your phone to turn it off and then turn on the bike to get the change. I didn't see the need for it in any of my situations since I don't park my scooter in such a large parking lot that I need a glowing screen to find it. Besides, there is still the Find My Scooter function in the Noodoe app so there is still something locating my AK to tell that app where it is. WiFi, BT, don't know which? It also must have other sensors running all the time to be able to sense the proximity of the remote fob in order to turn on in the first place. These all must be very low power or the battery would be run down rather quickly. It is not.
Anyway, there have been improvements in phantom loads causing the battery to be run down faster than on other bikes or scooters. From what I can gather the biggest improvements happened with those changes, some of which I didn't mention, that happened in 2018. Some more since then.
Just to see for myself how my own AK 550 battery held a charge... or not... I've been not connecting my Battery Tender Plus during all this week. I'm planning to continue to not plug it in for the whole month just to watch and see what happens. So far I've gone for a few rides during this week with 3 days between rides once, 2 days between rides once, and each day otherwise. I've turned the bike on each day to look at the voltage level indicated. Right after each ride, after a rest of maybe 10 minutes, the voltage level indicated about 12.7 v or 12.9 v. By several hours later the voltage level is indicated to be 12.3 v, and if I watch it for a few minutes it actually increases to 12.4 v rather consistently. Even after turning on the bike to check air pressure just before I go for a ride I'll leave the bike on while I adjust the psi in each tire and the indicated voltage seems to sit at 12.3 v or 12.4 v the entire time I'm letting air into or out of the tires.
This issue was one of my very minor concerns with the AK 550 and through what I've been doing this week and will continue to do the rest of the month I am feeling like it may possibly be a non-issue now with changes Kymco has done to address this. I'll report more later if I experience any change to how it has been going so far.
Just FYI for those who might be interested.