Advanced charge techniques guarantee full state-of-charge and safe operation even under adverse conditions.

Below 0C (32F), the Duro applies a trickle charge to warm up the nickel-based battery, then switches to fast-charge on reaching operating temperature. A charge time-out timer prevents a prolonged charge at low temperature. For safety reasons, lithium-ion does not charge below 5C (41F).

Above 50C (123F), the Duro allows the battery to cool down to 45C (113F) before taking on a charge or resuming from a previous charge. Should the temperature remain high, a time-out timer terminates the battery with a fail indication. Preventing charge at high temperatures protects battery and equipment and achieves optimal safety.
* Temperature sensing requires a thermistor in the battery or in the adapter

The termination methods of nickel-based batteries are based on negative delta V, plateau timer and dT/dt. Lithium-ion terminates on a current saturation. Redundant detection methods provide safe charging, even if the battery is known to be defective.

The user often has the choice of utilizing nickel or lithium-based batteries. Duro adapters automatically detect the battery type and select the correct charge algorithm. Nickel and lithium-based batteries can be charged in the same adapter.*
* Only for batteries with usable identification code

Operators often require monitoring voice traffic while the radio is in the charger. The Duro makes this possible by applying a topping charge after energy has been dispensed. With the Duro charger, a two-way radio can in essence become a base station.

Two light signals indicate charging, ready and fail status. Fail denotes a battery that is shorted, unable to follow the predicted voltage pattern or other anomalies. A fail condition terminates service to protect the battery and charger and alerts the user with a flashing red LED.

When discharged too low, some lithium-ion batteries appear dead and cannot be recharged. The Duro charger recognizes this condition and reactivates the pack’s safety circuit with charge pulses. On reaching normal voltage, a fast-charge completes the charge.

Bay 1 and 2 of the Duro B5 are equipped with discharge circuits. This feature reverses memory on nickel-based batteries and calibrates SMBus packs. Batteries in constant use should be serviced once every 1-3 months to prolong battery life and retain an accurate digital readout. The B5 recognizes the need for calibration by flashing the red LED for 15 seconds.

The Duro B-system services SMBus batteries by communicating with the internal battery flags and resetting the state-of-charge indicator on full charge.

The Duro chargers can be installed in a vehicle to service 3.6 to 7.2 volts batteries. Higher voltage batteries can be serviced by adding a third-party external DC-to-DC converter. Cadex offers several mounting options that allow horizontal or vertical mounting. Typical charger locations are the transmission hub, firewall, trunk floor and the wall in a truck. The installation is quick and simple.