Hi interested in the ecosystem
Is there a big difference in the wired vs battery version?
I know the battery comes with Homebase but is it needed? there’s a good price difference between both
Also can you expand the Homebase2 storage?
Thanks
I was quite content with the video that Lifehackster made, comparing both versions: Eufy Battery Video Doorbell VS Wired Version - Comparison of Features, Video & Audio Quality - YouTube
He has videos on both individual doorbells as well.
The battery variant requires the homebase to operate. If you plan to add motion/entry sensors and additional eufycams, you already have the homebase and everything integrates very nicely (speaking from experience with also two keypads).
As for the homebase 2 storage, it is not expandable (yet). The 16GB however are more than enough to store videos on. The wired doorbell has 4GB of internal storage, which is gone when it gets stolen. The battery variant can also be hooked up to the existing wires so it’s charged all the time.
Hopefully this information helps! 
Agreed with @John0 on the Lifehackster reviews. Great stuff.
I would note that there’s a new “Pro” version of the 2k wired doorbell with 32gb storage that’s available for $169.99 now at BestBuy. Seems to be a BestBuy exclusive. I’m trying to document it a bit here, as there’s not much else on the web about it: 32gb Video Doorbell 2k Pro (wired) -- some sleuthing