What is the optimal battery configurations for mobile/portable operations?

||What is the optimal battery configurations for mobile/portable operations?
What is the optimal battery configurations for mobile/portable operations? 2017-11-27T14:35:04+00:00

Home Forums Ask The Elmer What is the optimal battery configurations for mobile/portable operations?

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  • Jerry Shaw
    Participant
    Post count: 2

    What is the optimal battery configuration when operating at remote locations using batteries, if each battery/pack you have will allow you to operate for one hour. If you bring 4 batteries, is it best to use one battery/pack at a time and swap them when needed or wire all of four batteries/packs in parallel?

  • Grace, Ray
    Participant
    Post count: 4

    I need a bit more information, you asked for a “mobile/portable” configuration. Either operation will have different requirements. Mobile tends to indicate a motor vechular of sorts, while Portable would suggest carring the battery to a location different from where you park to where you plan to setup and operate. The next question is how much power do you need. For a 100-watt tranceiver at 13.5 VDC, the average TX power is about 23 Amps key down and 2 Amps on Receive. Thats 25 Amps, if your average transmit time is 10-minutes per hour, your average power = 25/5, or 5-AmpHours. So you car battery, rated at 85-AH for 17-hrs. Using a small battery, 7.5 AH SLA battery about 1H-15Mins.
    Remember to monitor the battery voltage and discharge to no lower than 10 Volts DC. Remember to calculate the total power required by measuring amperage at the iput to your mobile/portable station.

    Here is an example of my Elecraft KX3 station onfigured for portable operation, regardless of mode, I’m mostly tuning around, listening. I call when my chances are good. As a result, my TX:RX ratio is something like 1:10.

    RX current is around 150 mA. TX at 10 W is about 2000 mA. The average current drain of my 6Ah SLA is on the order of 150 + 2000/9 = 372 mA. Time: RX 90%, TX 10%)

    The internal battery should then be good for about 6000maH/372ma = 6.6 hours. In practice it could be more (if you run lower power for at least part of the time) or less (if current drain is higher due to the particular load you’re working into, battery wasn’t fully charged, etc.).

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