Garmin Index scale battery drain in two days

Question

I bought the Garmin Index Scale in 2016. 
 It has always worked well and batteries lasted around 6 months. 
 Around 2 months ago, the batteries have started to drain in two days. I have changed them a few times and the issue remains, so it is not the batteries. 
 Some people are saying it is a connection issue and the scale is constanlty either connecting or sending information through the wifi. 
 
 Can Garmin please support. Just because there is a new version, it does not mean we have to scrap the current one and buy the new version. 
 
 Regards, Pedro

unbrickU · Answer

I ran into the same problem with the Garmin Index Scale S1 (you posted for S2). In my case I traced it down to the WINC1500 Wi-Fi module. It was drawing exactly the amount that would drain a AA battery in two days. 
 Replacing the Module was a little tricky, since the scale used the Rev A of the WINC1500 which is hard to get these days. The Rev B is still available (paid 25&euro;). The Rev B came with a much newer firmware preinstalled which turned out to be a problem. Since the hardware revision was different I couldn't just flash the firmware I dumped from the old one. The Scale is running version 19.4.10 of the host driver, which isn't compatible with 19.4.4 or 19.5.x or newer which are available in old ASF releases. The 19.4.10 doesn't seem to exist on the Internet anywhere. I ended up getting the 19.4.10 Firmware directly from the Microchip support. After adding the go daddy root certificate (which was as easy as dropping the cer file into a directory) the scale was finally working again with the normal power draw. 
 TLDR; the Wi-Fi module was the culprit. It can be replaced with a WINC1500 Rev B, but it needs flashing of the 19.4.10 firmware (for the index scale S1) and the go daddy root certificate. 
 PS: Since I first thought the replacement wifi module was bad, I got a second one. So now I have a spare one with no use, in case you are interested. I could also flash you the right firmware if you have the S1. 
 EDIT: also from my Investigation into the Fault I can conclude with high confidence that there wasn't any wrong doing from Garmin (because I read some speculations). It isn't like a bad firmware from Garmin that would overly use the wifi or something or the Garmin firmware driving the wifi chip wrong. It's also nothing they could have fixed with a firmware update. It is simply the WiFi module they sourced from Atmel/Microchip developing a subtle hardware fault/leakage after a decade. Also I couldn't see any design flaws that were obvious to me. They even made sure to use the latest wifi firmware that was available for the Rev A chip.