You could of course have used something smalled than the XT60 plug. That one is unnessecarily big. But I suppose it will do if you are having a "scramble parts together" project 
The idea with the XT60 was to use standard parts, the size was of secondary consideration, but I thought it might just squeeze in to the case (it probably would with a little effort), but having it on a flying lead actually makes life easier. I am trying to keep everything modular, I'll use the same connectors on the PIR switch, a regulator module and a modified Ikea alarm clock. It should all just snap together in a Lego like fashion. The XT60 is pretty common on all sorts of battery configurations, (and is an open source design SFAIK), so using this as my standard made sense.
Anyway, thanks for the battery advice earlier. I have a lot of left over LiPo's that I don't use anymore. They are in pretty OK shape and I'm thinking of using them in parallel. They are 3S though, so I need to use one of my voltage regulators.
3S gives approx 12.5V which will give you better efficiency from the regulator, than trying to drive it from 3.7V
Another plan is to buy some beefy 1S (3.7V) LiPo's. Something like this Zippy 6200mAh. Or maybe go even more DIY (and cheaper) with this naked 5800mAh cell. If I would take 3 in parallel, I would get like a solid 18Ah and that should have my 240HS running for some days.
That would certainly do the trick for reasonably long shoots. Running them in series with the regulator on the output is another option.
You were talking about the Schottky's, so I ordered 50x 1N5822's on eBay. But do I just put on each plus (+) wire of each battery and then put all batteries together?
The diodes allow you to parallel up cells or sources without having to balance them. Highest voltage wins, when it discharges and is no longer the highest voltage, the next one takes over. The diodes ensure they don't discharge into each other. Any diode with a high enough current rating will do, but schottky ones have less of a forward voltage drop than traditional vanilla silicon rectifier diodes, which matters when you are dealing with low voltages as we are. I'll provide a circuit diagram it you want, but you probably get the idea, its pretty much as you describe. As previously stated, this is a good arrangement if you want to hot swap the batteries and/or other power sources without powering off.
By the way, have you seen this Solar charger circuit from Adalight? Of course it is more expensive but also better quality than the chinese versions on eBay, but is it the same functionality?
I saw that too. I uses one of
these. and is probably quite effective. Theoretically it looks like it would cope with up to 1A charging current, so good for a fairly small set up.
I liked your referral to the magic smoke

