Batteries

All About Transmitter Batteries

We thought that you might find it useful for us to give you an insight into the interesting world of transmitter batteries. (We know it's not that interesting, but we had to do our homework so you may as well share the results!).

Battery Capacity and Shelf Life:

Just a few words on battery capacity. This tends to be given by the manufacturers in mAh (milli amp hours) and this figure gives us an idea how much current can be supplied by the battery and for how long. For example, a battery which had a capacity given as 40mAh will be able to supply 40 milliamps for an hour or 20 milliamps for two hours.
The shelf life of batteries is determined by storage temperature and their chemistry. Typically, at 21 degrees Celsius a Silver Oxide battery will lose less than 10% a year, an Alkaline button cell about the same and Lithium button cells less than 2% a year. This loss decreases as the storage temperature decreases.

Battery Chemistry:

With respect to button cells there are 3 main types of chemistry, Silver Oxide, Alkaline or Lithium. The Lithium batteries are usually 3 Volts and the Silver Oxide and Alkaline button cells will be 1.5 Volts.

Silver Oxide or Alkaline:

Since Silver Oxide and Alkaline button cells give the same voltage (1.5 Volts) then which battery do you choose?
Where Silver Oxide cells score over their alkaline counterpart is in their ability to maintain a more stable voltage. This characteristic makes them better for clocks and watches and absolutely essential for falconry transmitters and metering equipment (like light meters in cameras for example) where a stable voltage is required. An Alkaline cell though is good for high current devices where a stable voltage is not required, for example, in electronic toys and calculators. So to summarise, if your application calls for a stable voltage under load (watches, clocks, falconry transmitters, metering equipment etc.) Use a Silver Oxide battery.