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).