1600 mAh
Flat top- according to my user guide, my Lambo 4 can support either battery type.
The battery does last me all day, but I only have normal functionality for 10 hits, maybe less. Operating at 4.8 volts all the time. After 10 or so hits, the Lambo blinks as if the battery has run out. If I just keep trying to hit it, it eventually works. Quite annoying though.
I use a Smoktech tank. Link here.
I also use a pretty thin, clear juice, link here.