Hammerhead vs VegetaHd

[uri]

Hello,
I've recently changed from a vegetaHd to a refurbished Aliexpress Hammerhead.
I've noticed some differences between them and I would like to now your opinion.

Battery consumption:
After 3 years using the vegetaHd battery still lasts 1 day. Hammerhead lasts less than 1 day. Is there any way to get the health info of the battery? May I change the HammerHead's 2013 battery? How muchs does you Hammerhead batt last?

I've noticed more bandwidth usage on Hammerhead than Vegeta. Same list of apps on both phones. Any clue?

Bluetooth: Both phones don't work on parrot ck3100 or mki9000 with phonecalls. I haven't tried music streaming on mki9000.
Phonecalls doesn't work connected to a bluetooth speaker (Muzilli), but music streaming works well. Any luck making hammerhead work with bluetooth?

And last. Video playback of my own videos taken with hammerhead, are not played. "The video format is not compatible".

Any hints?
Opinions?
Thanks

[TotalSonic]

@uri - as far as your problem with video playback goes - this is a known problem solely on the Nexus 5 - one work around is to use the UTMedia app instead of the default Media Player app.
https://open-store.io/app/utmedia.nfsprodriver

In regards to battery - I don't have direct experience with this - but there are a lot of replacement batteries available for it on the online markets - and instructions on how to change it can be seen here - https://www.ifixit.com/Guide/Nexus+5+Battery+Replacement/26009

Best regards,
Steve Berson