Technical Notes – Altronix SMP3 / SMP5 Power Supplies Not Compatible with ELK-965

(Battery Charging Voltage too Low)

The Altronix SMP3 or SMP5 power supplies will not deliver sufficient voltage to keep a sealed lead acid battery properly charged when used with an ELK-965. The SMP3 and SMP5 units incorporate a 39 ohm current limiting resistor in their battery charging circuit which is too high for proper ELK-965 operation. For proper battery charging operation with an ELK-965, a power supply’s current limiting resistor must be 10 ohms or less to supply a charging voltage of 13.5 to 13.8 volts.

For more information, contact technical support at (800) 797-9355, or

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