A few years ago I was asked about my preferred batteries for camera flash units – which to be honest, at the time I hadn’t really given much thought to, I just utilised whatever was on hand. But as time went on and my reliance on flash units increased, I began to notice an increasing number of under exposed or black images showing up in my collection of photos because one or all of my flashes hadn’t fired as required. It was at this point that I started experimenting with various battery types and discovered the obvious differences.
Before we begin discussing batteries, it is important that we understanding how a camera flash unit works. These devices momentarily simulate the sun by providing a huge blast of light – and just like the sun it requires a large mass of energy to produce that blast. To do this, the flash unit draws power from the small batteries (typically AA sized 1.5 volt units) and boosts it through the use of a capacitor. The capacitor takes the 1.5 volts and stockpiles it until it reaches several hundred volts. Once the flash is triggered, the capacitor rapidly discharges the power stored, producing the bright flash visible through the flash unit’sbulb.