Are these Efest 3.7V batteries more suitable than the ones directly above (or are both good)?

Thanks, would these do the job? ..In a 2xAA + 2xAA (side by side) in D adaptors with blanks?

Thanks for the replies. Would the best thing to do without changing flywheels and motors etc (due to misalignment) is to rewire and use stronger batteries?

If so, what is the maximum voltage I can run with the stock gear? ...and recommended number of AA 3.7Vs/blanks? Would it be 2xAA 3.7V and 2 x AA blanks in D adapters?

Thanks for the replies. What is the maximum voltage I can run with the stock gear? I take it all that would be replaced are the stock motors, wiring and switches (all internal original plastic bits and gears would be sufficient with increased voltages)?

Are there any existing links or guides showing which wiring, motors etc are best to get and where? 

"Also, 3x 3.7V will burn out stock motors. you want 2 IMRs and 2 dummy cells. DO NOT USE Trustfires, or Ultrafires. Use efest of windyfire IMR cells. A rewire and 2S lipo or 7.2NiMH would be better if you don't want to replace motors."

...would this mean 2 x 3.7v AA batteries with 2 dummies could run on stock with a rewire? Thanks again.

Hi 1st post here. I bought the Hyperfire recently. I'm looking to find out what are the quickest and easiest mods to upgrade performance?

I've seen some videos online about removing the lock and simplifying the internals etc (does this increase power?). 

Also seen some battery kits with "3x 3.7v & dummy AA with 4x D shape converters" (are these any good?)

There doesn't appear to be a quick list of things to do. Thanks in advance.