It really depends on what you seek in a dash cam as "best" is subjective.

Video quality should be better than 1080 and 720 cams but on the other hand, i think its missing a rear cam and uses battery instead of a capacitor but thats my opinion.

Are you seeking to upgrade?

Best not to use a powerbank with a dashcam as there are cases of the powerbank exploding inside the car. Also, any lithium ion batteries are not good in hot weather.

Please don't run dashcam without parking mode function 24/7. The dashcam will overheat and dies immaturely.

If you want to use parking mode, best to invest in a Korean dashcam like Thinkware with true parking mode and get their battery pack using iron phosphate. Their battery pack can last continuously for about 36-48 hours running parking mode.

If without their parking mode and you hardwire to your car fusebox, max is about 12-24 hours which depends on your car battery condition, power level, etc. Thinkware dashcam has car battery protection which prevents battery drain.

Because Yi dashcam doesn't have parking mode function.

The battery inside is just to make sure the last video file is saved in the microSD and the settings are saved. Not for recording when the engine is off.

I have a question. Are all dashcam able to withstand the heat in Malaysia? If we always park the car at an open space, will it reduce the lifespan of the dashcam?

Experienced before Yi dashcam can last about 1.5 years until it cannot hold a charge anymore. Everyday park outside in the sun and rain. But this mostly depends on the brand and quality of the dashcams.

Issues with lithium-ion batteries will differ. 1) Some cannot charge any more 2) gets bloated 3) starts leaking 4) worst case explodes.

Best to go for dashcams using supercapacitor as they'll last longer than those dashcams using lithium-ion batteries.