A while back I purchased a DC barrel plug for my Yaesu FT5D HT from Amazon. This particular HT uses a very small barrel plug which is not a common size that I would have extras of.

The FT5D like many other HTs use a 12 volt DC input for charging the battery pack. The exact power requirement is 10.5 volts to 16 volts.

My plan with the plug I purchased was to put PowerPole connectors on the other end so that I can connect the HT to my DC power block at home or in the car for convenient charging.

While this did work perfectly fine, I was browsing Amazon and they suggested an item that is quite interesting:

These require a USB-C port capable of Power Delivery (PD). It comes with a variety of connector sizes, and conveniently one which fits the FT5D.

Many HTs still have barrel connectors for charging, few have USB-C ports. I am sure over time more models will support USB-C for charging.

Power Delivery

Power Delivery is a handshake between devices which allows them to negotiate the voltage and current levels for transfer of power.

By default, the legacy standard of 5V is the voltage potential unless negotiated otherwise.

However, not all PD sources support all voltages. In my case, my Anker battery pack supported 9 volts but not 12 volts.

Needless to say, this would not work with the FT5D which likes to see at least 10.5 volts input.

USB Power Delivery (PD) supports 5, 9, 15, and 20 volts (for fixed voltages):

Some PD standards allow for variable voltages in the range of 3.3 volts to 20 volts for example.

I also tried every other PD power source I had access to, such as an Anker PD wall charger, MacBook Pro power adapter and many others. None of them supported a 12 volt output level.

Skipping Power Delivery for USB

I avoided looking for a battery pack which would support 12 volt PD output, since many product descriptions do not offer specific details on what output voltages are supported or what power delivery standards they support.

Instead, I tried a boost converter which requires a standard USB-A connector at 5 volts and boosts the voltage directly to 12 volts.

All of my portable battery packs have a USB-A connection for charging.

DC Polarity

The polarity of the barrel plug output is center or tip positive with the ring negative. This matches the polarity on all of the various HTs that I have.

However, if needed, you can add a small patch cable which reverses the polarity:

Since the FT5D polarity is center tip positive and the boost converter is the same, I did not need a polarity reverser.

Success

The boost converter worked well! It was able to charge the battery pack in the FT5D will the same speed as if it were plugged directly into a 12 volt DC power block.

I measured 12 volts from the output of the boost converter:

I then plugged it into the the FT5D:

The portable pocket-sized batteries I use can recharge the HT several times before they need a charge. I usually take one of these batteries with me if I am away from a charging source for a while, mainly for my phone. Now I can use the same battery to charge HTs as well, if operating portable for extended periods or during power outages.

The FT5D in particular has a strange charging setup. When plugging in an external 12 volt power source, it disconnects the battery as a supply and the radio is powered entirely by the 12 volt external source. The HT then feeds some of this power to the battery for charging.

Since the HT is powered by the 12 volt external source, it would not be recommend to transmit on high power when using this particular USB boost converter. The boost converter can deliver a maximum of 1.2 amps at 12 volts.

The HT requires 1.6 amps (at 13.8 volts) for 2-meter transmit, and 1.9 amps for 70cm transmit at high power.

With this HT (or any other which has APRS), if the modem is enabled and beaconing is enabled, then it could transmit at any time. The HT should be turned off for charging by this method, or, APRS should be disabled.

Other Voltages

There are USB boost converters which have variable output voltages as well as fixed voltages. This could be useful if you have an HT or other device which needs a voltage other than 9 volts or 12 volts.

The down side to these is that they are not only bigger, but the voltage adjustment is not menu driven, but via a potentiometer. These would not be ideal for real portable operation where the voltage can be accidentally changed, such as putting an HT into a backpack while charging it.

I suppose you could remove the knobs from the potentiometers after setting the voltage to prevent accidental changes.

Final Thoughts

I was hoping the Power Delivery (PD) sources I had would support a 12 volt output but none that I have did. This means the USB-C to 12 volt cables will not work for me.

However, all of my battery packs have a USB-A connector and the cost of the USB-A boost converter was about the same as the USB-C to 12 volt cables.

I do not think I would recommend the USB-C versions for 12 volt output unless the cable specifically calls out what PD standard is needed, and if battery packs or other power delivery source did the same. If your HT can charge from a 9 volt source, then the 9 volt version would work.