Using a pair of 7.4v LiPo packs

[MegatronUK]

I'm using a pair of 4000mAh 7.4v LiPo packs (two cells per pack) in my project was wondering how to connect them up.

The document here http://forums.benheck.com/viewtopic.php?f=43&t=30962" onclick="window.open(this.href);return false; is very helpful and easy to understand - like that diagram shows I also do not plan on charging the batteries while in use (I'll installing a SPDT switch to select either the +7.4v battery OR +7.5v DC line and the common line from that switch then powering the system.).

Is it simply the case that both P+ connections from the two protection circuits should lead to this SPDT switch? I don't have to put anything on the individual lines before that, do I? The P- connections, along with the DC -ve line will all go to a common -ve solder point.

For charging, I have a DB9 port on the case specifially for the charger, with 4 pins wired up - I believe I should be connecting these to P+ and P- on each protection circuit? There'll be a similar arrangement on the outside with two flying leads; one per pack, effectively each 7.4v pack will be charged up individually.

Does this all make sense? I haven't left anything out?

[MegatronUK]

Having just read-read all that again I think I'm missing a dpst switch to toggle the batteries between On / Charge, when On I want the outputs connected to give the full ~8000mAh, but that's no good to charge them; the outputs need to broken otherwise it will be trying to charge 4 cells.

So, I think a dpst should toggle the lines marked with a "?" on/off on the following image depending on whether I want them linked and powering the system, or seperate, for charging purposes.