Wouxun KG-UV3D Battery Capacity

After I get the next GPS+voice interface running on the (yet-to-be-bought) Wouxun KG-UV3D radio, a pair of reasonably new 1A17KG-3 7.4 V 1.7 A·h lithium battery packs will be floating around with nothing to do; the GPS interface connects an external battery to the radio, so there’s no need for the OEM battery.

Before doing anything else, it’d be useful to know the actual capacity. The pack has flush terminals, so I snipped off two lengths of shield braid, jammed a wire into each one, and taped them in place:

Battery pack - braid contacts
Battery pack – braid contacts

That obviously wasn’t going to last, so I added some closed-cell foam:

Battery pack - foam compression
Battery pack – foam compression

And then, ever so gently, crunched a clamp around the whole mess:

Battery Pack - clamped contacts
Battery Pack – clamped contacts

Crude, but workable, although the ragged start to the test showed I was too gentle. Another click of the clamp and everything settled down just fine:

Wouxun Pack
Wouxun Pack

In round numbers, the pack delivers 1.6 A·h down to 7.0 V and then falls off very rapidly to the 6.0 V that ended the test.

A string of three red / amber LEDs adds up to 3×1.9 = 5.7 V. A dumb DC blinky light running from 7.4 V has 77% efficiency, which isn’t all that bad, and 70% at the start. A current-regulating switcher might give 85% to 90% at the cost of considerable circuit complexity and wouldn’t be feasible for four independent blinky channels.

The starting voltage, fresh from the charger, is just shy of 8.5 V, which is why I figured I could get away with 9 V from the external pack through the GPS interface. So far, so good.

Obviously, if those packs are to be useful, I must conjure up a better battery holder. Having already designed a battery-shaped case for the GPS interface, it should be easy enough to build a radio-shaped mount for the pack.

10 thoughts on “Wouxun KG-UV3D Battery Capacity

  1. WU-Zhun CNC THING-O-Matic battery cases
    only $9.95 BUT WAIT!! We’ll throw in a picture of ED! FREEEEE!!!!


    1. a picture of ED! FREEEEE!!!!

      And for only $99.95 more, you can get a 3D printed portrait of his shop assistant!

  2. I can’t imagine why you’d need to design a battery holder; that approach looks like it works fine!


    1. Clamp the battery to the light and the bike!

      I knew I was missing something obvious…

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