So I have a larger hole in the handguard now because I'm an idiot. Great. I wish the instructions said something about this. Also, no the instructions didn't explain how to get it in there. The instructions that come with it are for the 551 SWAT. These stick batteries any smaller than the Mini?

Yup...
Batteries don't pick and choose which gun they're work in, and guns don't pick and choose what batteries they'll work with :p

Does your car still run if you fill it with gas from Esso instead of Shell?

No, but my wallet sure wouldn't be okay with it. :P

No your car doesn't still work if you do that?

Uhhhh....what?

Opps, meant to say yes. :D Errrr, I mean.... "No, damn Volkswagens! They don't work with certain gas stations!"

a stick battery would be the size of one battery in diameter but as long as seven of them put end to end...

Huh...there's not enough room to put in anything longer.

ok... so what's the extact type of 552 do you have? Commando... SWAT.. ??

It says 552 commando.

Dude it's the same thing as the pictures on the first page without the battery holder. Cut that stupid plastic wrap holding the wiring to the outter barrel. Put the fuse box and battery connector in the lower handgaurd. Once tha is done connect the battey and install the lower hanguard while the battery is free floating. Once the lower is in place angle the 8.4 on it's side at around 45 degrees and install the upper handgaurd.

Right after the 9 minute mark this guy will take the battery out of the forgrip; it looks to be a Lipo but it seems to be the same size as the 8.4V mini. The battery is just sitting on top of the barrel in the foregrip...

YouTube- ICS SIG 551 and SIG 552 REWIEW (3)

Tried this. There's nothing connecting the wires to the barrel, it just looks like that. I tried what you're saying, there is JUST not enough room to lock both pieces in.

What the hell? I tried for 3 straight hours to do that. I just tried again, and it simply is just too chunky. Maybe I should get a new battery.

and you're sure it's an 8.4 mini like the one in the pics I posted earlier?

Indeed. Used it for the longest time in my P-90, and I doubt anything else fits in that.