Specifications

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Charging Technology
Historically PMR users have had little choice when their batteries need to be recharged. Some methods still used
today can be traced back to the invention of the rechargeable battery. While conventional charging techniques
successfully put energy back into batteries they do not take into account the individual chemical state of each
battery. In other words traditional chargers simply push energy in to the battery without regard to what the
battery really requires.
The main problem with traditional battery charging is that the discipline of the operator must be relied upon to
ensure the procedure is carried out to best effect without degrading the battery. OEM chargers detail a variety of
rules that need to be followed. Few users have the time or the patience to stick to the complicated regime
recommended by manufacturers. As a result many organisations invest significant resources on battery
management to combat the problems caused by antiquated charging methods.
The following section gives a brief overview of the different battery charging methods available.
Trickle Charger
The trickle or slow charger is the standard unit provided by most handset manufacturers. The unit works by
pushing a steady current in to the battery at a rate which is normally 10% of the battery's capacity. So for example
a 1700mAh battery will be charged at 170mAh. Typical charge times range from 8 to 12 hours.
It is left to the user to terminate the charge at the correct time. Failure to remove the battery from the charger
means that more energy enters the battery than it can absorb. This causes a host of degenerative chemical
processes within the battery that lead to reduced capacities and premature failure. In the worst cases the
temperature inside the cells will become so high that the battery vents off the gas build up.
Benefits
Drawbacks
 Lowest Cost
 Often included with radio
 Long charge times
 Requires user discipline
 Constant rate of charge
 No conditioning process
 Long formation times
 No termination of charge
 Detrimental to the battery
Charge profile for trickle charger showing constant current input