Elecraft KBT2 - Manual (Page 10)

10
Keep the battery connected to the charging/operating power supply whenever possible, and recharge it
immediately when you return from field operation. Up to 16 hours may be needed to bring the battery up to
full capacity, depending on the depth of discharge. Storing the battery in an uncharged state will quickly
reduce its life due to sulfation. Self-discharge shelf life is only about one year at room temperature.
Temperature Extremes
The life of a lead-acid battery will be much shorter if the battery is stored or operated at high temperatures.
For example, the self-discharge shelf life will be cut about in half if the battery is stored at 35
° C (95 ° F)
versus 20 ° C (68 ° F).
Do not use the battery if the ambient temperature is below –10 ° C (14 ° F) or above 50 ° C (122 ° F). If the
ambient temperature is above 33 ° C (90 ° F), keep the K2 out of direct sunlight since the temperature inside
the cabinet can be much higher.
If you frequently recharge the battery at other than room temperature, you’ll need a temperature-
compensated power supply or charger. 14.0 V can be used from about 10 to 35
° C (50 to 95 ° F). A higher
charge voltage is required at lower temperatures, and lower voltage is needed at higher temperatures.
Consult Elecraft if you have special charging temperature requirements.
Shipping the K2 With the Internal Battery Installed
Anytime the K2 is transported with the battery installed, be sure that the battery disable switch is in the
OFF position. This will prevent power-up of the transceiver in the event that the on-off switch is
inadvertently depressed.
Before shipping the K2 by any method, consult the shipper to be sure that they can safely accommodate
battery-powered equipment.