Battery pack switching Series to Parallel

Hi Everyone,

Heres my project/idea: Basically, I want to switch a battery pack from a series configuration to a parallel configuration (during charging) and back again (during discharging) using MOSFET switches.

This would be nifty for the following reasons:

a) Hobby shops sell something similar, but you have to manually connect and disconnect the batteries yourself: **broken link removed**
b) You can charge any battery pack from the same source if they are connected to this circuit
c) Your cells are connected in parallel while charging, which causes your battery pack to balance itself without a balancing circuit (during charging anyway)

I Have attached a picture of analogue switches required and a picture of the circuit I built using MOSFETS in the simulation program Crocclips. (Which seems to work in simulation)

I know I can probably use relays, but MOSFETS are so much more elegant...

Would the design work with the N-Channel mosfets I use?

I don't think it will work. When a switch is open, the related FET gates are "floating" at an indeterminate voltage. I don't think you can guarantee that they will all turn off.

There may be other problems but I didn't bother to look further than this.