[Stridex]

Dual bats in zips are just pointless if you ask me. Unless...

Here's what I'd do if I was you. Buy a small bit or cheap clone. Take that "much" smaller board out and replace it in your zip. Now you can fit two batteries without flipping the board. When Zips make a van body or if you can find one, you can flip the board on it's side and stack as many bats as you want.

The dual bats will increase runtimes in Zips as is, but don't expect more speed. The PCB only lets so much current thru as it is. While the bits(clones) PCB boards do not regulate the current-nearly as much. Yes, people have had a lot of success and speed increases with what you want to do, but don't forget... those success stories came from bit or clones owners. Zip owners that tell you they saw a lot of speed are fooling them selves. I've done every mod in the book.

IMO, this is a must mod for zip owners. Imagine the speed of a bit with the control of the zip. You just can't get any better.