Battery questions
 

So i have a JG MP5 SD5, Kraken and a GJ M4. All wired to deans and i use 9.6v or 8.4v. Is that more or less the norm for everyone or should i look at a stronger battery...like an 11v? That sounds like too much just form the little i know about it. All these guns have some sort of minor upgrades such as barrels,hop-ups,pistons,motors and springs. Pros vs cons to battery strength? Cheers!!!

8.4v are perfectly acceptable. You don't even need 9.6v, but if you have that/use that it's fine.
8.4v is the norm for stock guns, or even upgraded guns (I use an 8.4v large for my 380fps AUG).
9.6v for higher rate of fire with upgraded guns, but I've found my rate of fire is great, probably due to my gun being wired in deans. I don't want too high a rate of fire anyways, just wastes ammo.

11v will seriously kill your gun unless you do the mods to support it. For the most part I use 8.4v. That gives my G36 a ROF of 12.5 RPS.. the real G36 shoots 12 RPS... would you want your airsoft gun shooting faster than real steel? I recently switch to a 9.4v for quicker trigger response and because I uprated the spring.

I also agree with Styrak that high ROF just waists ammo. I f**king hate playing against people with high ROF setups and highcaps. It's like "Oh yay.. another MP5 machine gun..."

not true... I used a stock Echo1 G36K with an 11.1 volt lipo for probably 2k shots, opened it up, and there was no excess wear or damage on the piston, or anywhere else.

Yea, but it takes longer to go through 2000 rounds on a lower voltage battery, so life of the gun is sped up but not shortened.

2k isn't that much dude. Besides, stock JG guns have so much gooey shit in the mechbox, and such a stiff spring, that I'm convinced it actually slows down the ROF considerably.

My JG P90 came stock with a 9.4 and didn't fire any faster than my G36 on an 8.4.