Battery time.

Clocks like this are available from most charity shops for a very small amount of cash. Those tiny portable alarm clocks can be bought brand new for about one pound (roughly two dollars). They are a useful addition to any ghosthunter's equipment collection. Cheap enough that you don't care if they are lost or broken and could potentially provide very useful information. As long as you don't buy the digital ones where the screen blanks when it's out of power.

Confused? Well, think of it this way. Many investigators report sudden loss of power in battery-driven equipment, particularly cameras and camcorders and especially where rechargeable batteries are used. The frequency of such reports suggests there is something about ghosts or about the locations they are in that causes batteries to spontaneously drain.

The problem in this theory is that digital cameras and camcorders are remarkably effective at killing batteries on their own. One camera I recently disposed of could wipe out a pair of cheap AA cells in under a minute. They'd come out hot. I had to take the batteries out of that camera when it wasn't in use because even the good quality batteries would die in hours.

The display on cameras, phones, and other digital gadgetry normally includes a three-bar battery power indicator. This can sometimes go from three bars to zero at a stroke: sometimes it's because of a lot of stored images (which uses power all the time) or because the indicator isn't all that good. As a rough guide, fine, but don't rely on it.

So in most of the equipment where battery power is spontaneously drained, it's impossible to be sure it's not just the equipment doing it. In other words, if your phone dies ten minutes after you charged it, it does not constitute proof of anything supernatural. A faulty charger or battery, a poor connection between charger and phone, an inaccurate indicator, all these and more could be valid reasons. The loss of battery power in such equipment proves nothing.

It occurred to me that when I put a single AA battery in one of these clocks, I don't have to replace it for about a year. The clock takes a tiny amount of power at a remarkably regular rate. Spontaneous loss of power just doesn't happen unless the battery is faulty and that's very rare.

So if you place a few of these very cheap clocks, all set to the correct time, around a site, you can forget about them while you investigate. At the end of the investigation, collect them and note whether they still work and show the correct time. You will need to check beforehand that they reliably keep time for about 24 hours, naturally.

These cost next to nothing and they will tell you whether there has been a partial or temporary loss of power and how long that lasted, simply by comparing the times shown on the clocks. They will tell you whether a total loss of battery occurred and better still - they will show the exact time it happened.

As long as you have kept notes of any strange occurrences along with the time of those occurrences (I used a spring-driven watch for this!) you can compare the time of any dead clocks with your notes.

In theory at least, a battery-draining ghost could be tracked along their route by the times on the clocks that stop as they pass.

Before you head for the Ghostly Gadget Shop to empty your wallet on equipment you aren't trained to use, first consider how you can make use of much cheaper sources of information. You might spend ten pounds on charity-shop clocks and get no result. Would you rather spend hundreds on a tri-field meter and still get no results? If you decide to quit ghosthunting in the future, you can always find another use for clocks!

Browse charity and second-hand shops and think ghosthunting while you do it. Investigations require persistence and patience and a lot of thought and planning, but they don't have to be expensive.