These cells have distinct safety advantages compared to nickel cadmium and nickel metal hydride cells particularly when they are overloaded or age. When the cells deteriorate with age, the chemical reaction in the lithium manganese cell does not produce the highly explosive hydrogen gas. In addition to this, there is no danger of the explosive reaction between lithium and cobalt metals, which is possible in lithium ion cells.
Thanks to this stability and safety in the lithium manganese cells, Hartenberger has constructed a lamp that can be charged without opening the housing, an attractive feature for divers, but one they were unable to endorse without the application of lithium manganese cells.
Despite the ability to charge the lamps in a closed housing, the Nano compact lamps also have the plug in power pack for quick and simple replacement of the cell pack making a 2nd cell pack an ideal companion on dive trips. This feature also allows the user to replace an aged cell pack without the need and expense of sending the lamp in to a specialist workshop for cell replacement. The re-charging time of the lamp with the standard world wide charger takes approx. 3 hours.
A modern micro processor controls the electronics in the lamp and provides numerous features and information for the user:
The magnetic field surrounding the switch is constantly monitored and prevents the lamp from being activated by an external magnet/magnetic field. The standard high performance 20W HLX halogen bulb is supplied with a carefully controlled over-voltage power that increases the performance of the bulb more than 25%. An electrical current limiter controls the sensitive start up phase of the halogen bulb when the lamp is turned on, ensuring that the bulb, despite the over voltage, has a life expectancy of approx 100 hours.
The 4 stage brightness control allows the user to individually set the lamp to the ambient conditions. The brightness set and the resulting remaining burn time are both shown in the LED display.
A low discharge protection device shuts the lamp down avoiding a drastic reduction in cell voltage below acceptable levels. Before the low discharge protection cuts is activated, the lamp warns the user of the imminent end of the lamp burn time with 3 blinks. Just before the lamp shuts down, the lamp will blink continuously to warn the user that the lamp is about to switch off. Reducing the brightness setting of the lamp extends the burn time and the lamp will burn continuously again for a limited time.
If the lamp fails while operating, the LED display turns on and serves as emergency lighting. As with all Hartenberger lamps, an automatic SOS signal (Morse alphabet, 3 x short, 3 x long, 3 x short blinks) can be activated if the user is in a distress situation.