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Author Topic: Portable power option Yaesu FT-100D  (Read 327 times)

Posts: 10

« on: Yesterday at 03:46:00 PM »

Hi, Im not sure were about on the forum to ask regarding this question so think this is closest to my

Ok guys, I have a Yaesu FT-100D in my car with the Atas 120A and love getting out and about using it mobile but I also like parking up somewhere and using the radio as well with the engine switched off and as this radio is not designed as a QRP transceiver is can draw up to 22 amps when using 100w power which doesn't be long draining out the battery. If the battery drains I end up sticking on my portable jump pack to start the car.
I want to know a good portable option and looking to use solar power, I know about these units causing some RF but not too bothered. What I'd like to know...what would be the best battery to use with this set up and how many watts and current output solar unit could I get away with? I wont be constantly contesting on full power while using the radio, just picking up random QSO's but this radio would draw 3.8 amp on 10 watts. I had thought about a second battery charging off the cars alternator but don't want too much stress on the alternator plus the cars electronics are pretty sensitive as regards to faults and this could be throwing up a few unnecessary codes as well as me still having a constant drain and having to start the car to recharge anyway so I'd rather avoid having to do this. If I knew what battery and what size of portable solar unit to buy I'd be on it and out doing some decent portable work with my feet I was hoping 40w unit but seeing the drain I might need 80w or a 100w unit hence needing you guys for some advice:) I would just love to park the car up with the doors open, solar panel at the rear and sit back and enjoy this great hobby:)

The radio power requirements are 13.8v DC, it's 22amp draw at max power (100w). Receive (squelched) 1.2amp draw and max audio is 1.6amp draw.


Posts: 537

« Reply #1 on: Yesterday at 06:04:57 PM »

You may want to consult with a business that installs high end stereo systems. Solar panels to provide enough power to keep your battery at a decent level would be expensive and large.
I think the idea of a high capacity gel cell battery or even two of them, along with a battery isolator to keep the radio battery separate from the cars starting battery would be best.
You will most likely want to upgrade your alternator to one with a higher charge rate and perhaps one that charges more at lower RPM.


Posts: 10

« Reply #2 on: Today at 02:16:01 AM »

Hi, thanks for the reply, I don't think I'll be changing anything on the car, even for a replacement alternator it's around £600 so I'd hate to guess what an energy efficient one would end up costing and all that money and still having to run the engine to keep it charged when I can just use it now off it's standard setup and keeping the engine
I think the problem is because the radio draws so much power. I was going to run the radio of my jump pack to see how long it lasts and when it drains this pack can be charged using the cigarette lighter in the car, this way I will have no drain on the car battery but I have a feeling the jump pack won't last very long as it's not the biggest battery out I'd rather spend the money on the portable solar power, at least I can take it with me if I change my car:)

Posts: 4707


« Reply #3 on: Today at 02:02:39 PM »

I also like parking up somewhere and using the radio as well with the engine switched off

How much time are we talking about here?  A few hours?  In that case, operating SSB or CW you're not going to kill a typical car battery.  Because the radio will poop out due to low voltage before the battery will get too low to start the car, you're almost assured you'll never be stranded.

But just for the sake of argument, you can determine pretty closely just how many Ah you're going to draw with the particular modes/duty cycles you're going to use and can preemptively run the car to replace used Ah.  Even for an aggressive duty cycle at 100W, running the engine for 10 minutes per hour would be plenty.

Yes, you could set yourself up with panels and batteries but buying and managing all that isn't plug and play.  You have to store the stuff, schlep it around, set it up, tear it down and monitor it during use not to mention the purchase price plus replacing the battery now and again.  Contrast that to just driving to the spot with the car you already have and using the existing battery and alternator which already work.  Total extra cost = $0.  As added insurance you could put a watt hour meter inline and know exactly how many Ah you've used, and restart as often as you like based on your actual discharge level.

When I go camping I run lights, radios and assorted gizmos and only need to recharge for 30 minutes or so once a day.  An afternoon's operating shouldn't be any problem at all.

Mark K5LXP
Albuquerque, NM

Posts: 10

« Reply #4 on: Today at 03:11:23 PM »

Yeah I hear ya Mark, I just get worried about being stranded as you well know we all end up in some mad, although I always have the jumper pack in the car just in case.
I think I'm just attracted to the whole idea of totally portable as well but as you say, I'd have to then schlep it around. I was thinking of using the radio on and off for around 4-5 hours so it would be a good olde drain on the battery. I'm going to head off tomorrow for a while and use the radio just to see how long I will actually get out of the car battery before it dies and then just jump start it of the jumper pack. If I don't get too long I'll look at other options. My car takes a fair bit to crank up being a 2.2 diesel and it's always running it's own fault checks in the background even when the car it turned off so more drain.
Also, would it be safe to connect the solar panels to the cars own battery under the hood while I DX with the engine off and then just take it off again when I'm finished and ready to start the car? That way I wont need a separate battery and the panels can keep injecting charge into the cars battery the whole time I DX.

I was watching at a guy on Youtube using a Zamp 40w kit and a 12v 18ah battery with an Icom IC-718 pushing 100 watts and this radio will draw 20amps on full power but the guy had no problems at all. I was actually thinking of getting an AGM 12v 50ah or 100ah battery and a Bosch 40w kit and just make sure I start off with a fully charged battery, that way the kit will keep it charged during any hard use and when I take a break I can just turn off the radio so there's no load. The kit comes with all the connections and as my radio is in the boot off the car I have connectors already in place. Altogether I would just take out the folding solar panels and screw in the radio leads to the load terminals and clip on the battery leads to the battery and good to go. I don't have any tuner as I am using the Atas 120A but I'd still like the option to bring the radio into a tent or something sometime in the future and use it with different radios.

Anyway, I'll do some DX tomorrow and see how long I get and let you know:)
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