Slimline USB Charger For Tiny Ham Radios

The recent trend to smaller and smaller handy talkie (HT) transceivers is approaching the limits of the human interface. Sure, engineers could probably continue shrinking the Baofeng and Wouxun HTs further, but pretty soon they’ll just be too small to operate. And it’s getting to the point where the accessories, particularly the battery charging trays, are getting bulkier than the radios. With that in mind, [Mads Hobye] decided to slim down his backpacking loadout by designing a slimline USB charger for his Baofeng HT.

Lacking an external charging jack but sporting a 3.7 volt battery pack with exposed charging terminals on the rear, [Mads] cleverly capitalized on the belt clip to apply spring tension to a laser-cut acrylic plate. A pair of bolts makes contact with the charging terminals on the battery pack, and the attached USB cable allows him to connect to an off-the-shelf 3.7 volt LiPo USB charger, easy to come by in multicopter circles. YMMV – the Baofeng UV-5R dual-band HT sitting on my desk has a 7.4 volt battery pack, so I’d have to make some adjustments. But you have to applaud the simplicity of the build and its packability relative to the OEM charging setup.

This isn’t the first time we’ve seen [Mads] on Hackaday. He and the FabLab RUC crew were recently featured with their open-source robotic arm.

12 thoughts on “Slimline USB Charger For Tiny Ham Radios

  1. There is something wrong with this article!
    The article says some “adjustments” have to be made for uv-5r. All UV series radios with one exception have 7.4 volt batteries, the UV-3R, which already comes with a USB charger.
    So how do you charge a 7.4 volt battery with a 5 volt charger? How do you balance the battery?
    Some details and fact checking please!

    1. It appears he’s got one of those really chintzy USB LiPo chargers that fits in the USB connector end. I spotted that at first when a group of us was discussing it in our lab and had concerns but then noticed that, yes, eBay will sell you a $3 USB connector LiPo charger that puts out 7.4V.

      Also, eh, if the battery blows up, it’s only a $30 radio (and your life, but that’s an aside). Baofengs are plentiful on the marketplace.

      I wouldn’t trust this on my Kenwood TH-D72 any day.

        1. Yep, the chinese have came out with a whole line of vhf/uhf two way radios, they’re just cheap commerical radios that used to only be sold in china but they discovered they could be sold in the US as ham radios. They’re very low quality, as you might guess, but they do work and are very very cheap.

  2. A UV-5 is HUUUGE compared to a Yaesu VX-2, and my Radio Shack HTX-420 from 25 years ago is only slightly larger than a UV-5. I think we’ve long since reached and passed the point where transceiver electronics can be shrunk past the point of reasonable. There is a certain minimum size that the marketplace supports, and that is just small enough but not too small to operate. We’ve been there for at least 20 years.

  3. Hey don’t Diss the UV-5’s too much. I just got my Tech license and a UV came as part of the package deal. Replace the rubber duck antenna with something like a Nagoya 771 and I can hit the local repeaters just fine.

  4. I have a UV-5R with an additional hi-cap battery that adds nearly half again Tue length of the unit. But I can operate for a couple of days without recharge. The HT and battery are bright yellow as well, precluding loss while in the wilds. I’ve operated with this radio in several US states, as well as Germany and Poland, without a hitch. I also have a Wouxun that is semi permanently in my Jeep, and also serves for sat comms. Good solid units.

    Mobile, AL

  5. It an interesting article. I have a few bf fi p’s.
    The charging tray is a problem and I like the idea of a USB plug straight to the battery .
    I have found these radios very capable if you understand their capabilities.
    I have waterproofed them, added rat tails and the nag 771.
    They can be easily altered to send and receive down to 126 and that’s in the aviation band.
    At 70 usd each I and others have the ability to communicate reliably and world wide with sms messaging and emails.
    I hold a general license and am happy with the gear.
    So a USB direct plug in is something I have been looking for.

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