http://www.personal-view.com/talks/discussion/3008/black-magic-is-internal-battery-complete-disaster-or-reliable-solution

This is Tilta power solution. Not very cheap, but made to last and has much better connectors compared to competition.

I think that indeed, it is very good that there is an internal battery + DC connector.

Everyone who would seriously need such camera would need external powering solution... so the internal battery is a great backup.

Remember, this is not run&gun camera, where the size matters.

@Vitaliy_Kiselev

I doubt it would start charging unpredictably.. it will start charging as soon as you connect the 12V DC... and will fully charge... so if you will not plug out the 12V DC, it shouldn't start charging again...

Well.. I'd say lets wait and see. In my personal opinion, I would prefer this same solution with GH2 as well - to have battery + DC plug... and not the stupid DC coupler.

it will start charging as soon as you connect the 12V DC... and will fully charge

I was talking about different situation. Many owners (and most serious ones) will have external power constantly connected. If you look at notes behaviour, they start small recharging unpredictably (if you have DC plugged over long time). Same thing will happen if your camera just had uncharged battery - you'll get much worse internal temperature, as it'll be charging during shot.

We also do not know many parameters, like maximum percentage usage of the battery (must be high, as they optimized external design). Such batteries degrade very fast, and if you combine it with very pretty battery position, it could be even worse.

"Randyman" on another site suggested this relatively inexpensive 12VDC battery system from SmallHD might be useful with the BMCC: http://www.smallhd.com/Store/8-9-inch-HD-Monitor-Accessories/SmallHD-26-Watt-Hour-Battery

Their mounting bracket could possibly be adapted to attach via one of the cam's 1/4-20 threaded holes, or on a rig, etc.: http://www.smallhd.com/Store/5-6-inch-HD-Monitor-Accessories/Battery-Bracket-for-DP6

According to Adam Wilt's 2nd article on the BMCC, the cam draws 18 watts: http://provideocoalition.com/index.php/awilt/story/nab_2012_is_bmd_the_new_red_part_2

Concerning Vitaliy's good point about the internal battery's charging cycle heat and its possible affect on video quality: Hopefully the cam's cooling system can handle the situation, but we probably won't know for sure until after the camera ships.

Cheers.

Here's one of the first power accessories for the Black Magic camera.

http://www.thephoblographer.com/2012/07/03/exclusive-switronix-confirmed-to-be-releasing-blackmagic-powerbase/