You can handle an infinite amount of mAh.
What it does is that it allows your gun to run longer between charges (my large battery lasts me a whole day). The general consensus is that 1 milliamp = 1 shot give or take depending on climatic conditions that you're playing in (winter vs spring vs summer, daytime (hot) vs nighttime (cooler), etc).
I believe that you can do Li-po to fit a higher voltage in a smaller space but it's not really recommended unless you upgrade your gun to handle the inherent higher voltage as you can do lots of damage to your gun that may be expensive to fix.
ಠ_ಠLess QQ more Pew Pew
READY TO >> RACE