BAOFENG UV5R

A  very simple modification for a Baofeng battery.

MM7BQP

Craig

 

 I own a few different models of hand helds but always carry a Baofeng with me if I'm out up the hills a walk. Baofengs are cheap but under estimated little radios. I've compared them to various brands and they compare really well considering the price. They do suffer very slightly on the receive side as they tend to get flooded easily but where I use them this isn't a concern. Other than that what's not to like for the price? 

 

I use the standard battery on the Baofeng but also wanted to run the radio on AA cells. One of the club members mentioned that a battery case for 6 AA cells is available so I ordered one to try out on the radio to see how it performed.

The Battery case arrived and out of the box had a dead short as it hadn't been assembled correctly but after a little modification it was working well with 6 AA rechargeable cells. 

The only thing that was niggling was the build quality of the case as it doesn't look as if it would stand up to being opened and closed to charge up the batteries too often.

With this in mind I decided to modify the case to fit a charging port and reduce wear and tear opening the little plastic lugs that hold the AA battery case together.  A barrel connector a diode a couple of wires is all it takes.  A little heat shrink to tidy up and the jobs finished.  A really simple project to do but it brings a couple of advantages to the Baofeng UV5R.

The obvious one is that the AA batteries can now be charged without having to be constantly removed, which will prolong the battery case life. More importantly it means I can now charge the radio on the go while it's being carried in the bag as I use a USB battery bank and cable to step up from 5v to charge voltage. It also means that when the batteries in the case eventually fail to hold charge I can replace them with whatever capacity of cells are available.

A good addition to a cheap and cheerful wee radio.

Inside-case.png

The  barrel connector, diode and wiring. As you can see from the image there's enough space inside the battery case for the connector to be fitted in easily. There's no need for any charge circuitry inside the battery case as it's handled from the USB cable circuit. The cells used in the image are 2000mAh but can easily be changed for higher capacity when available.

charge-cable.png

The charging cable used.

These can be bought online very cheaply. They are designed to be used on a Baofeng charging dock. The cable steps up the 5v supplied from the USB port to a suitable charge voltage for the Baofeng.  I measured the output voltage from this one and found that it gives the perfect charge voltage for 6 AA rechargeables.  By happy coincidence it also falls into tolerance for my Yaesu charging dock as you can see from the attached reminder label :)

front-with-plug.png

The radio shown charging 6 AA cells using the barrel connector modification and the USB step up cable.

Everything works perfectly normally and the charging cable indicates charge ready lights from red to green as normal.

Craig

MM7BQP