I've listed and linked to most of the Kr8 suppliers in
The "Best" Electronic Cigarette article.
Vapor4Life has the largest selection of prefilled cartomizers. [I recommend their Premium and WOW lines.] V4L and
many others carry both auto and manual
batteries. [Tip: V4L's prices and shipping costs are reasonable but not the lowest. However, they
frequently have major discount code sales at close to 20% off ... offered to those who have registered on their website.]
Manual and auto
batteries (of the same size) are 280 mAh and provide the same number of puffs per charge. There also are 380 mAh XL batteries and 180 mAh short batteries. I don't like the manual Kr8 battery: The button is more recessed than on the 510 and often sticks and can get lodged inside the battery housing. The Kr8 automatic batts function very well; much better than, say, 510 auto batteries.
BTW, there is a very quick and easy way to refill Kr8 cartomizers: Doggsbody's Carto Cap (aka Condom) Technique, demonstrated here by Doctor Vapor.