Tag: battery

Multi-Purpose Outing

Heading out for some portable operations yesterday, I had a few objectives in mind. First, I needed to take some pictures of an antenna mount for an article I’m working on. I also wanted to do a POTA activation, while also making some Winter Field Day (WFD) contacts. Lastly, I wanted to try out an inexpensive LiFePO4 battery I recently purchased.

I planned to do all this stuff while at Ridley Creek State Park (K-1414, KFF-1414). I started off by setting up to take the pictures for the article. After getting the shots I needed, I set up to get on the air. Today, I was using my KX3 (5 watts CW) and 12-foot loaded whip. I also had a 29-foot vertical wire fed through a 9:1 unun.

My POTA/Winter Field Day setup. The straight key was pressed into service for a Straight Key Century Club contact.
My POTA/Winter Field Day setup. The straight key was pressed into service for a Straight Key Century Club contact.

I finished setting up about 10 minutes before WFD kicked off, so I started calling “CQ POTA” on 30M. By the time WFD started, I had the required 10 POTA contacts in the log. After marking myself as “QRT” on the POTA spotting page, I started “searching and pouncing” on the bands. I was hunting for WFD, POTA, or anything else that seemed interesting. 

After a little under two hours, I wrapped up with 25 contacts in my log. Thirteen of them were WFD contacts. I also had a park-to-park QSO with AA4XX down in North Carolina. It’s always a pleasure to work Paul. A Straight Key Century Club contact with K3Y/8 rounded out my log.

The battery I was using today was a 6 Ah LiFePO4 battery I found on Amazon for about $20 (US). My trusty Bioenno batteries are still hanging tough after more than six years of use, but I was curious to see how this cheap battery would work. It did just fine, but we’ll see how it holds up over time.

The $20 6Ah LiFePO4 battery I used for the first time today. It got the job done.
The $20 6Ah LiFePO4 battery I used for the first time today. It got the job done.

With some welcomed mild weather yesterday, this wasn’t the most wintry of Winter Field Days here in Pennsylvania. I wish I had more time for it this weekend, but life had other plans for me. Best of luck to everyone taking part in WFD.

73, Craig WB3GCK

Li-Ion Battery Pack

Here’s a little battery pack I put together for use as an external, portable power source for my YouKits HB-1B.  I wanted something relatively lightweight and inexpensive that would put out at least 13 volts.  This solution has fit the bill, so far.

There isn’t too much to it.  I already had some Li-Ion cells on hand, so I wanted to make use of them.  They are 18650 cells with a 6000 maH rating.  I haven’t actually verified the claimed capacity but most cells tend to be somewhat over-rated. These particular cells are the “protected” type; each cell contains some circuitry that prevents overcharge and over-discharge.  There are much cheaper unprotected cells but I’d rather be safe than sorry.

Battery pack with cable stowed
Battery pack with cable stowed

To put it together, I bought a 4-cell battery holder for 18650-size cells.  With 4 fully charged cells, the voltage can exceed 16 volts.  To keep the voltage below 14 volts (the maximum for my HB-1B), I put 3 silicon diodes in series with the output.  This brings the voltage down to about 13.7 volts with fully charged cells.  I also added a 2-amp fuse and an Anderson Powerpole connector.

Li-Ion battery pack layout
Li-Ion battery pack layout

To package it, I had a sandwich-sized Rubbermaid container that wasn’t being used.  It turned out to be the perfect size to hold everything snugly.  When not in use, everything is neatly tucked inside the container.  In use, I lift one corner of the lid to bring out the connector.

Battery pack as I normally use it
Battery pack as I normally use it

For charging, I remove the cells from the holder and charge them with a Nitecore D4 charger.  This is a 4-bay smart charger.  It automatically detects the type of battery inserted and applies the proper charging method.  Each bay works independently, so balanced charging is not an issue.  The D4 works with a variety of battery types (Ni-Cad, NiMH, Li-Ion, etc.) so it is a handy accessory in the shack.

Nitecore D4 smart charger. Each cell is charged independently.
Nitecore D4 smart charger. Each cell is charged independently.

I haven’t done any formal testing of this battery arrangement, but it has provided adequate power for an afternoon of portable operating.  For extended operating sessions, I throw 4 extra cells in my backpack that I can swap in if needed.

It’s not the most elegant solution but it works fine.

72, Craig WB3GCK