Capdiamont\’s Weblog

Built external battery pack for HT
Saturday 11 Aug 2012, 05:36
Filed under: Electronics and Computers, Eureka, Ham/Amateur Radio, Humboldt | Tags:

Originally it was just a eight cell “D” battery holder for an old digital camera. Then it was a 12v power supply for projects. I have a Lithium-ion and a “AAA” battery holder for my handheld transceiver(HT).  I like to run both voice and APRS on the radio at the same time at the high power setting. That efficiently means for a day’s worth of running around, I have to use both, and make sure I remember to switch battery types in the menus of the radio. I could reduce to Milli-Watt range if there was more coverage. That would save on the power consumption, distances prevent that.

The Lithium-ion has a rating of 1,800mAh, and the “AAA” batteries 1,000mAh. The radio does have a DC jack which says 13.5v and I run it off the car’s 12v nominal system. Being the long unused battery pack gave 12v(8*1.5v) at 12,000mAh, I figured it should work fine for powering the radio. I also had a camera case I was given, that sat unused.  A test proved the battery-pack fit the camera case. I was thinking of direct connecting a wire with the right plug to the battery case. Then I thought it would be nice to quickly change connections and be able to charge my phone. That meant using a cigarette lighter jack, and as  a bonus an in-line fuse.

I cut the wire down to fit the case better. Assembled, and tested with the radio. Failure. The radio was continuously power cycling. No attempt to transmit was possible. Grumble. So add in another battery as a test. Good. Run to Radio Shack for a one “D” cell battery holder. Test fit it in to the camera case was good. Wire up new combo, and test was good! The blue stuff you see is Sugru, a nice air curing rubber like substance. I used it to stick the new battery holder on to the old one, plus insulate the positive wires  to prevent shorts. I love that stuff.
Reflections: The batteries fit a bit tight for the springs. Some batteries did not make contact at first. I figure with “D” cells I wouldn’t have to worry about carrying a charger.

Comments Off on Built external battery pack for HT

Comments are closed.

%d bloggers like this: