Battery Chargers

Batteries in emergency devices are most times the weakest component, and most prone to failure. In many cases the main cause of failure is due to the heat that the battery is exposed to. The battery temp rises while charging and generally the more power that is pushed into a battery, the higher the temperature becomes. To make this worse once the battery has reached its full capacity and charging continues the battery temperature will rise further.

Single rate battery chargers

Typically to lessen the cost of a product a device will have a single rate charger. This charger normally does not switch off when the battery is charged or does not reduce its charge rate. This means that the battery temperature will be defined as follows:

Battery Temperature = Ambient Temp + Temp rise of enclosure + Temp rise from normal charge + Temp rise after charged.

In many cases this high temperature can negatively impact the life of the battery and cause early failures.

Dual rate battery chargers

Dual rate chargers lessen the long term temperature experienced by the battery. Once the battery is nearly 100% charged the charger will drop down to a lower charge rate. This reduces the normal charge temperature and the temperature rise experienced after the battery is charged. This technology also reduces the power consumption of the emergency device and reduces the cost to the consumer.