Regarding my Lezyne Mega XL...

Battery life: I’ve been keeping track of it but frankly it’s been a bit difficult to accurately measure, partly because I’m just doing little rides these days along with time spent configuring it and partly because the device doesn’t give very good info on that as far as I can tell. If it just told me what percent the battery was at instead of a partially filled battery icon I could say better. That said, I think it will do 30 hours of riding time (which doesn’t include any time it’s on when not moving or recording) at least. Next charge I will do a better measurement and report back.

Mapping w/o phone: Yeah, that works. I tried it today. You have to load a map into it first. There are online reviews that go into more detail. I’m still working on the mapping stuff which isn’t too important for me.

I’ll also say that I got mine for <$150 online. Some place in the UK I think it was...