Over time, my POTA activation kit has grown smaller, due in no small part to a reduction in battery size. I’ve transitioned from a 60AH, to 30AH, and finally a 15AH Lithium Iron Phosphate (LiFePO4) battery. Understanding the power requirements of my activation radio after 50+ outings has allowed me to activate with confidence that I won’t run out of power.
With an understanding that Rhode Island is fairly rare, my activations almost always generate a pile-up, and maintaining a rate of 1 contact per minute (60 an hour) is easy to do. At this point I plan on the following:
- CW Activation 5.5 AH per hour of operation
- SSB Activations 5.1 AH per hour of operation
Yep, CW takes more power on average!
Since LiFePO4 batteries allow you to safely consume in excess of 90% of their rated capacity before the battery voltage tails off significantly, that pretty much says I can have about 2.5 hours of heavy operating time using a 15 AH battery. In my world, that corresponds to 2 parks between charges. Using that rule of thumb, I’ve never run out of power in the field, and I’ve done as many as 4 shorter 30 minute activations in a single day.
I do carry a smaller 9 AH battery as a “backup”, but I’ve only used it once in 50+ activations (and that was because my primary battery failed).
Is this power consumption at 100W? If not, how much power are you running the radio at?
Hi Nick,
That’s a glaring oversite on my part – yep 100 watts (or as Icom says 100% Power). While I do love QRP, and have built and used many QRP rigs, with POTA I’ve always been of the opinion that I make folks work hard enough to hunt me without adding low power into the mix, so I run 100 watts. That said, I always enjoy working the QRP activators, even if copy is sometimes by ESP!
73, Bob, WB4SON
I too enjoy QRP and I do POTA activations with barefoot QRP rigs on a semi-regular basis. Occasionally, I use a 20 watt radio. However, for the vast majority of my activations I run about 50 watts. Some with a 100W radio turned down and some with a Hardrock 50 Amp.
Power-wise, it’s 10db more than 5W/QRP and only 3db down from 100W and the power draw from the battery is measurably less. It might be worth a try for an activation or two to see what the draw is from your IC-7300 at half power and how that compares to your 5.5/5.1 numbers for full power.