I'd suggest regular rechargeable. A brand called Eneloop. They discharge at a lower rate than most brands. While not in use.

ok, thanks

Noted, thanks

best way to go. i also do this.  Good old Energizer

I'm using Eneloops for everyting. Not the highest power, but they don't discharge that fast while not in use.

Can't say the exact hours, but I started Pikmin 3 with full batteries and had to recharge them once to finish the game. But I turned off the rumble and speaker because they're annoying.

I just use regular old rechargeable AA's. I don't think you can really get better than that, and they're undoubtedly cheaper than buying Wii-specific packs, even when you include the charger. Plus you can use them for anything else as well. I use them for my 360 controllers too.

well I wouldn't be able to tell you exactly how many hours they last but like I said I have no complains, I go for days without having to charge them. As for a developer I don't think I can recommend a specific one, I have used like 3 different brands and they all get the job done

this... eneloops have been the best for a few years now

http://www.metaefficient.com/rechargeable-batteries/best-rechargeable-batteries-battery-chargers.html
http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Delectronics&field-keywords=eneloop
(great user reviews)

you can get the pro version for more high powered devices

mine are just simple duracell battlers... ha ha