Icom IC-705: Let’s see how long it’ll receive with supplied BP-272 Li-ion battery pack

The shortwave radio listener part of me might actually be more excited about the Icom IC-705 than the ham radio operator part of me.

The IC-705 has a number of features for ham radio operators who also enjoy broadcast listening. For example, it sports:

  • a general coverage receiver,
  • good performance specs,
  • notch filtering (both manual and automatic),
  • Icom twin passband filtering,
  • an AM bandwidth filter maximum width of 10 kHz
  • built-in digital recording of both received and transmitted audio,
  • audio treble/bass adjustments,
  • and battery power from Icom HT Li-ion battery packs

The Icom IC-705 ships with an BP-272 Li-ion battery pack and since the announcement last year about the IC-705, I’ve been curious how long the BP-272 could power the IC-705 in receive only.

A real-world RX test

Yesterday morning, I resisted the urge to hunt POTA and SOTA stations with the IC-705 and, instead, spent the day simply listening.

I started the experiment with a fully-charged BP-272 7.4V 1880 mAh battery pack (the pack supplied with the IC-705). At 9:00 in the morning, I unplugged the IC-705 from my 12V power supply and ran the receiver all day on just the battery pack.

I made some practical changes to maximize play time: I turned on the screen saver, turned off GPS, set the LCD backlight auto adjustment to 2%, and set the screen timer to turn off after 1 minute.

I ran the volume somewhere between low and moderate and only raised it to what I would consider very loud a few times to copy weak signals. I listened to AM, SSB, and FM signals across the spectrum, but primarily cruised the HF bands.

Of course, I never transmitted with the IC-705 during this period (saving that for the next test).

I probably could have done more to decrease current drain, but frankly I wanted this to be based on how I’d likely configure the rig for use on an SWL DXpedition.


I unplugged the IC-705 from the 12V power supply at 9:00 local and the radio auto shut down at 16:39 local: a total of 7 hours, 39 minutes.

Honestly? I’m fairly impressed with this number mainly because it’s based on the smaller battery pack. The supplied BP-272 pack has 1880 mAh of capacity. The optional BP-307, on the other hand, has 3150 mAh of capacity.

If I decide to keep the IC-705, I will be very tempted to purchase a ($130 US) BP-307 pack as well.

Next test: How long can the IC-705 last on battery during a POTA activation?

As early as today, I will see just how long the BP-272 pack can operate the IC-705 during a POTA activation. This will be a true challenge on the smaller battery pack since POTA activations require a lot of transmitting (constant CQ calls and exchanges). There’ll be no lack of calling CQ on a day like today when propagation is so incredible poor.

Follow the tag IC-705 for more updates.

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16 thoughts on “Icom IC-705: Let’s see how long it’ll receive with supplied BP-272 Li-ion battery pack

  1. 13dka

    Re battery endurance… the German Wimo shop has measured the power consumption of all the parts that can be turned off on the IC-705:

    Display……………… 90mA
    GPS…………………… 25mA
    RX LED………………. 5mA
    WLAN………………. 1-2mA
    Bluetooth………… 1-2mA
    Mixer >25MHz…… 40mA
    RF Preamp………….10mA

    So the overall RX power consumptoin can be reduced from ~330mA to ~175mA. Powered via USB, the current drawn from the port is around 900mA when everything is on, 530mA with everything off.

    Of course they tried to make sure it doesn’t do everything the almost twice as pricey IC-R8600 does, so they restricted the RTTY decode function to 45 Bd ham RTTY, so no weather RTTY reception for us SWLs. The spec sheet says the AM filtering has a low cut off at 200Hz like on the IC-7300 but to my surprise it didn’t really sound like it does in your blind test (which obviously wasn’t blind enough at that spot :)).

      1. 13dka

        No, not yet. I’m pretty relaxed about that. Yeah OK that was a lie, it would take very little additional enabling to make me hit the purchase button. 🙂 TBH the only thing really keeping me from doing it is winter and that my car doesn’t have an engine-independent heater (alas one of the few cars where it’s really difficult to put one in), so it would see very little action until spring anyway. But then again, xmas is coming…. 🙂

        1. Thomas Post author

          Fact: Santa always swings by Japan en route to Germany. 🙂

          Seriously, had I not wanted to review this radio, I would have waited a bit. Typically within 6 months of introducing new models, Icom reduces prices. With that said…due to C-19, the demand is far out-weighing supply at present. Economics would tell you they’ve no incentive to lower prices until that supply catches up with demand.

          Father Christmas never studied economics, though, so there’s that to consider!

  2. Harald DL1AX

    I have read that it´s possible to power the IC-705 through its USB port. If that´s true, maybe you can use a good powerbank instead of the original battery. However, this needs confirmation.

    See basic manual on page 1-2:

    • To use a mobile device or a PC as an external power source, set the following item to “ON” (default).
    » SET > Function > USB Power Input (Phone, Tablet, PC)

    1. Don

      I have an automotive-type jump start box that has a 3.5 amp 12 volt accessory power output jack, and my IC-705 runs happily on it giving full 10 watts out. Lasted a full weekend with the cub scouts, and kept the cell phones topped off to boot!

    2. 13dka

      I just tested this using a “20,000 mAh” power bank (true capacity after 5V conversion and losses maybe ~12-13 Ah), after 18 hours of reception (with the BP-272 removed) the capacity indicator was down to 1 out of 4 LEDs on the power bank and I gave up. I think even in 2-way operation (when the BP-272 has to be inserted) this would give it an overall endurance way beyond my yapping or keying capacity.

      Of course a 6Ah 12V LiFePo4 battery would be my favorite choice for this radio. For bedside radio usage I run it with a surplus Huawei phone charger (again with the BP-272 taken out) that surprisingly turned out to be much less noisy than the others I have. All that flexibility in powering this thing is a big plus to me.

  3. Mark

    I still can’t believe that in todays Lithium battery world that Icom couldn’t install a 12v battery like Xiegu could in the X5105, at least it could have given it the full 10 watts output. + they charge rip off prices for the battery too, Li batteries are much cheaper today.

    1. John

      I agree they’re expensive.
      However, there’s an easy solution, simply purchase a third party equivalent (an Icom tech advised me to do this when one of their battery packs went south):
      BP272 = $99.95
      IC45L1-A (BP272 equivalent) = $46.00
      I’m sure there’ll be a third party equivalent for the BP-307 for sale soon.

  4. Paul B. Walker, Jr.

    Tempted? I know you’ll end up buying the larger battery pack, you know you will…. you wont be able to help yourself because youll wanna see how long itll last then.. and relish the fact you could go out in the field pretty much all day with the battery powered radio

  5. John

    I like getting these updates on particular aspects of the IC-705’s, maybe continue doing it that way and at the end submit the full review?

    For receive only that’s pretty good I think and is comparable with handhelds.

  6. 13dka

    $§&?&!!! Unfortunately that’s not bad at all, and knowing that there’s an optional battery which is probably good for 12 or more hours, making it last for an all-nighter including breakfast out at the dike is terrible news.

    Thank you for antedating this test! I will now precautionally delete the bookmarks for my local dealers and block Google on my computer before I tie my hands to the chair in anticipation of more test results. Maybe I’m lucky and it turns out to be deaf as a doornail, emitting funny odors and attracting mouse-sized mosquitos during further tests.



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