Sjcam M10 Action Cam

I grow increasingly frustrated with my Thinkware dashcam. At best, it takes 45 seconds to boot up. This in itself is ridiculously and unacceptably long. Sometimes it restarts and doesn't start recording for 2 minutes!

• https://mbni.blogspot.sg/2015/01/thinkware-x300.html
• https://mbni.blogspot.sg/2015/05/thinkware-x300-problems.html

So, I got the M10 (actually M10 wifi), mainly because it had auto start stop (search for action cam auto start stop), meaning when power is applied, it turns on and starts recording, and when power is removed, it shuts down.
MAIN PROBLEM: if you leave the battery in the camera and the camera in the car, the battery will swell in a few months. This sounds too dangerous. Fortunately it "works" without the battery, except the camera doesn't get to shut down properly so the last video is corrupted. Some people don't have this problem https://dashcamtalk.com/forum/threads/sjcam-m10-as-a-dashcam.13427/page-4#post-267637

Observations:

• The M10 starts up and starts recording within 10 seconds when power is applied. This just highlights how abysmal the Thinkware is.
• Videos are divided into a minimum of 3 minute blocks. There's less than a second gap between videos (I couldn't measure the gap on my watch). Remember, the last video is corrupted, so drives less than 3 minutes may not be recorded.
• Speaking of corrupted, I suspect the data is there (the file is), it's just missing the "packaging" (headers). So it should be fixable. This is also a problem on Dji drones and GoPros, and there are small programs to fix them. I didn't manage to fix the M10 videos though.
• Mine doesn't seem to have any internal power at all, if I remove the battery when the camera is off, even for a few seconds, the clock is reset.

Problems:
Update: This is complicated. I'm doing more tests. It seems files are ok before the card is full.
There's a major problem since I'm using it without the battery. The clock resets, and since files are named from the date and time, all the files have the same name and the camera wasn't designed to handle this. I'm not sure if it flat out doesn't save if there's already a file with the same name, or overwrites it, but most of my files couldn't be played and I couldn't find any of when just starting the car, the sole aim of this camera. If you're looking for a dash cam, a dedicated one may be better. Not really this camera's fault, it wasn't designed to be used without the battery.
Possible solutions?

• Set the clock / keep formatting the card - not practical.
• Manually start/stop recording at a random time so the files don't collide.
• Use the battery. Protect the camera from heat / avoid continuous charging to prevent battery swelling.

Update
It's not that bad. The filename format is:
yyyy_mmdd_hhmmss_xxx.MOV
where xxx is a kind of a running serial number. It's supposed to reset when the camera is switched off, but it takes longer than that (see how the first few files have serial numbers as high as 30. The date and time of 2016_0101_000005 indicates these files were the first created when the camera started, yet the serial number is already up to 30). Files are named with the time at the START of the recording. You can see most of the hhmmss in the files below are 000004 or 000005, showing that the clock starts 4-5 seconds before recording starts. Thanks to the serial number, there don't seem to be any conflicts.

The files without thumbnails are the corrupted ones because the camera wasn't shutdown properly.

So, the problems are:

1. Last file before shutdown is corrupted - you can avoid this simply by stopping recording before turning off the engine. It only takes 2 button presses and no waiting.
2. All the dates are the same so it's hard to tell which file is today's, yesterday's etc. 
3. When the card is full, overwriting older files doesn't work so well. Because the camera can't tell which files are really older when they all start with 2016_0101. In particular, it rewrites the 0 and 3 minute files first. Other files seem ok:

This is troublesome for me because the 0 and 3 minute files are exactly the files I want, those that cover the startup of the Thinkware camera.

Summary:
It seems to work ok until the card gets full and has to overwrite files. So if I format the card before it gets full, it can cover my needs, except the last file is corrupted.

Lens Cover:
The camera is nice, but it's not very popular and the bubble-shaped lens protrudes, so it's difficult to find lens caps/covers to protect the lens. You can use the waterproof casing. I found this one that sort of works:
https://www.gearbest.com/action-cameras-sport-dv-accessories/pp_1510542.html

"Minismile UV Filter Lens and Lens Cover Kit for Xiaomi YI II / 4K Action Sport Camera  -  BLACK 250035301"
The clear one is like a UV filter - you can use the camera with it on. It's a bit big. You can wrap some tape on the lens or filter to tighten it up. I use PTFE thread seal tape (plumbing "teflon" tape), which doesn't have any glue. There's some vignetting in the right corners, only visible in videos, not pictures. I think you can get rid of it if you position it just right.
The opaque cover fits and doesn't drop, but it touches the lens.

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