If you owned a one hour battery and a four hour battery, and you have a video shoot where you may be shooting continuously all day from 9:00 to 5:00 (with a one hour lunch break), which battery would you start with?

Assuming I can charge a batt on site, I would start with the 1-hour. Use it up and then throw it on the charger. Meanwhile shoot with the 4-hour. By the time it's run down, the 1-hour should be fully charged again.

What about swapping back to the 1 hour battery as soon as it is charged?

I would buy another battery so I knew I was safe, and if it was a stationary shoot off tripod and I could tap into AC I would use a power supply...of course thats if it was paid :)

Ha.

I'm not recommending a one hour and a 4 hour battery as the only batteries one should own or use, but in this scenario, that's all that is available.

1 hr first then charge
4 hr second then charge
1 hr third then charge
4 hr fourth then charge
1 hr fifth then charge

Ultimately you will run out of battery power as it usually takes longer to charge the battery than to use it in supplying power.

A third battery and at least a 2-hole battery charger would probably keep you shooting all day.

I'm told the Panasonic Batteries made specifically for the DVX-100 actually charge up faster than they can be used.

I'd test before I depended on that.