Recomended battery for IC-7300

Discussion in 'On the Road' started by KJ7LQB, Jun 28, 2020.

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  1. KJ7LQB

    KJ7LQB Ham Member QRZ Page

    I'm wondering what type (and specs for) of 12 volt battery would be ideal to run my Icom-7300 for a few hours in the field. I have a couple of solar panels to assist in charging while operating. I have a generator too, but would only wish to engage it as a last resort. Marine? deep cycle? cranking amps?
    Thanks in advance.
     
  2. KE0EYJ

    KE0EYJ Ham Member QRZ Page

    Lifepo4 12.8v at 15Ah.

    Bienno is a popular name.
     
    KU3X and W9WQA like this.
  3. W5UAA

    W5UAA Ham Member QRZ Page

    A few hours?

    For simple planning, we can disregard the discharge curve of batteries.

    An IC-7300 needs about 20 amps key down. 20 amp-hour battery will last 1 hour. 40 amp-hour will last two hours.

    Since CW is ~50% duty cycle, you can double the above numbers. SSB is maybe a bit less than 50% duty cycle. (20AH = 2 hours, 40AH = 4 hours, etc.) (15AH = less than an hour if you drain it to zero, which is not something you want to do to a Lithium polymer/Li-po battery--and they require a special charger also.)

    "Marine" batteries come in two flavors: either "starting" or deep cycle.

    Cranking amps implies standard car "starting" battery.

    Starting batteries are designed to produce a bunch of amps for a very short time (a few seconds) and then be immediately recharged. (Not good for ham radio... I mean, they'll work, but their life span won't be long if used the same way you use a deep cycle.)

    Deep cycles are designed to be discharged slowly for a long time, and then be recharged.

    Sounds like you want a deep cycle that will get down to no less than 30% in a "few hours". (You don't want to discharge a deep cycle to less than 20% or its life span is reduced.)

    Do the math, and then start shopping.

    I use a 110AH deep cycle for my portable ops. This past weekend, it ran my IC-7200 for 24 hours, 178 CW calls searched and pounced, and it got down to about 50% at the end.

    I think I'm going to get a "battery booster" when they become available again. (No MFJ-4416C's in stock at HRO.) As the battery discharges, the voltage drops (discharge curve). At 13.8 Volts (100% charge), my IC-7200 puts out 100 watts. At 12.0 volts (about 50% charge), the output drops to about 75 watts. A battery booster will keep the voltage at 13.8, keep my power out at 100 watts, but will drain the battery faster.
     
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  4. KE0EYJ

    KE0EYJ Ham Member QRZ Page

    The above is nuts akin to thread crapping.

    Do you plan to sit there with the key down 100% of the time? Or continually running CW tapping away constantly at 100w?

    Are you even running CW?

    You can ask this question here and get know-it-all thread craps from people who lug around massively heavy old-tech batteries via car and are too stubborn to switch, or try asking people who actually work in a field most of the time.

    Lifepo4
    12.8v at 15Ah. The BMS will be minimum 20 to 30 amps. Plenty for today's radios. Join the SOTA/POTA groups and ask. They'll tell you much the same.

    My Lifepo4 is only 9.9Ah, and I typically work for 2 to 3 hours SSB, calling anywhere between 25w to 75w, but am capable to 100w if I need to push it.

    A solar set-up will help keep you topped-off. I do not use solar. Mine is light enough to carry in a backpack.

    Try that with a car battery.

    Sure, a car battery will work, but much the same, you could lug your old Collins S-line set-up and make that work, also. But people don't -- take a guess as to why.
     
    Last edited: Jun 30, 2020
    WD4ELG likes this.
  5. W5UAA

    W5UAA Ham Member QRZ Page

    Thread crapping? My apologies. I'm merely speaking from experience. I explained how to do the math, then I said "do the math". He asked a general question, I answered it "generally." I admit 15Ah lasting less than an hour for an IC-7300 is over stating it--if he never transmits, it should last about 6 hours before damaging the battery. With a BMS and a large fold-out PV solar panel and full sun light, it'll last longer. How much longer? Well, do the math. Lots of variables here. And I'll admit the original question of operating for "a few hours" isn't too precise--he didn't even give a hint on what kind of operating he wants to do on battery. I have experience with a lead-acid battery and 100 watts CW (just recently with ARRL Field Day). So I gave my experience with CW and a Lead-acid battery. But I will say a LiPo battery needs special care compared to a lead-acid battery. And I never said carry a car battery. He asked a general question, I answered it "generally." And if he can carry a generator "in his back pack", I suppose adding a car battery wouldn't be too much extra weight either. I answered in context to the question. The question posed showed he doesn't know what a "marine" battery is--as if it's different from a "deep cycle" or a "starter", so I explained. I'm assuming just answering with a particular type of brand-specific battery only (that needs special care) will lead to disappointment if he doesn't know what a LiPo battery is and how it's different from a "marine" battery. Who's doing the "thread crapping" again? It's like someone asking the question, "What kind of antenna should I buy? Aerial? Vertical? Wire size? And then answering only with "Mosley Tribander" with no explanation.

    I'll try to be more careful in how I phrase my answers in the future. And since there's no feed back from the OP, we're just pointlessly discussing basic communication issues with subtle insults. I mean *really* basic communication issues. Sender -> Message -> Receiver -> Feedback. I don't like to be insulted and I don't like to insult others. Many hams claim to be communicators and really are masters at all the technical aspects of our hobby but totally suck at communicating with or with out electronic gear. The OP may be a troll. Trolls like to start these kinds of inflamed arguments among those who try to answer simple questions. But I'm assuming he's not a troll for the time being.

    No harm, no foul. Carry on. Peace out.
     
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  6. KE0EYJ

    KE0EYJ Ham Member QRZ Page

    Apologies, you caught me on a bad day.

    I went overboard.
     
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  7. KA1YBS

    KA1YBS XML Subscriber QRZ Page

    How about lowering the TX power to 50 or 25W. If you are on CW or one of those digi modes, hell, GO QRP!

    Other ways to lower battery requirements include using an efficient antenna without a tuner and operating from a hilltop.

    I use a measly 5w with a lousy Yaesu FT817 with a really lousy vertical and GASP... PHONE!!!!

    My 3Ah Bioenno LiFePo lasts 4-6 hours and my log is full.

    Not without saying it's usually frustrating as hell :D
     
    Last edited: Jul 13, 2020
    W1TRY likes this.
  8. KD2LFG

    KD2LFG XML Subscriber QRZ Page

    I have taken my IC 7300 to the field (picnic table portable) with a 10 AH LifePo4 battery and a 60 watt folding solar panel and everything stays topped off during daylight. Turn your power down and your mileage will vary. I can blast with a 100 watts when needed, otherwise I stay at 50-70 watts max. Invest in a good quality wire antenna and that should take you on out where you need to be.
     
  9. VE3WI

    VE3WI Ham Member QRZ Page

  10. WD0BCT

    WD0BCT Premium Subscriber QRZ Page

    After running a portable 100W rig (FT-891) with a 20AH battery a couple of times I quickly decided a QRP unit (MTR-3B) was a lot more more fun for going portable with. My goal is for the radio to fit in one pocket, the battery in another pocket, and the antenna in a light weight attache case or fanny pack. Occasionally I'll slip an FT-817 and antenna into a back pack...but that's as heavy as I want to get! I am not a pack animal and don't have roadies available.
     

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