What battery type can I use for a 2.47 volt 300ma Screw Base Lamp?

  1. profile image47
    olivier88posted 7 years ago

    What battery type can I use for a 2.47 volt 300ma Screw Base Lamp?

    I tried a 9volt battery and it seems to work fine, the only thing I don't know if that is the correct battery to use;  Meaning, how long will the battery last?

  2. Rik Ravado profile image92
    Rik Ravadoposted 7 years ago

    You should really be using a battery closer to 2.5V.  Two AA or AAA batteries in series are about 3 Volts so this would be better than the 9V.

    Although it works the bulb will draw too much current and that will shorten its life. 

    If you have a multimeter you could check the current and see if it is above the 300mA you are aiming for.  Hope this helps.

  3. Ben Evans profile image71
    Ben Evansposted 5 years ago

    If you have a 300 ma base lamp, you want to use two 1.5 volt D cells in series and a resistor.

    The resistor will take .53 volts @ 300ma so you would need approximately a 1.5 ohm resistor at 1/4 watt but I would use a 1/2 watt to be safe.

    Now the typical ampacity of a D cell is 12000 ma h and discharge is at 200 ma so the best configuration would be 4 D cells...............2 pair of series cells in parallel.    This would give you 80 hours.   You can most likely run this light without a resistor but with it the light will last longer.