A few tips about batteries:
- Always carry a spare for your camera (and everything else).
- LiIon batteries do not mind being charged without first being discharged, so charge them every time they go down – every day if you like.
- Once a month, exchange the spare with the camera battery, and top up if needed.
- For flashes, use NiMH batteries. These recharge more quickly between flashes. Plus, they save you money.
- And these do like to be occasionally discharged before charging again. You can get a “conditioning charger” for this (Lacrosse or Maha).
- These also discharge quickly by themselves, so top up before a shoot!
Do all this, and you are ready to live without battery hassles.