The term “Fire Jumpers” refers to the men and women who risk their lives to jump from airplanes and helicopters into remote regions where they attempt to control dangerous and destructive wildfires. While on the ground, they must remain as “light” as possible, carry only the most essential gear, yet remain mobile, functional, in communication, and have sources of artificial light when needed.
MW, one of a group of fire jumpers, was looking for a lightweight and durable means to power the portable electronic devices that he must use during his frequent fire-fighting missions in remote regions of southeastern California. His electronic devices are powered by rechargeable AA, AAA, and CR123 batteries, and include a 5-watt xenon LED flashlight, sets of Midland 16 mile radios with NOAA alert, an iPod with speaker dock, a GPS, a laser rangefinder, and a digital camera. Historically, when the batteries in one device run out of power, batteries from one device are switched to another, and recharging must wait until he has returned to an automobile or an AC power outlet. During prolonged fire-fighting missions, the loss of power due to discharged batteries is inconvenient and potentially dangerous for the group. To avoid loss of power, many of the fire jumpers carry multiple sets of extra batteries, and that adds weight to their already heavy payload. The battery charger he uses at home base is a fast charger by Energizer that can recharge four batteries in 15 minutes, and is not available. MW approached Powerenz to ask if we could design a custom portable solar power system that would allow him to recharge his AA, AAA, and CR123 batteries as needed in the field for prolonged periods of time. He needed a system that would: a. utilize solar energy for fuel, including a portable solar panel, b. be stored and carried in a durable bag that could be carried by a handle, shoulder strap, as a fanny pack, or attached to any MOLLE-compatible backpack or vest, c. be light-weight for long hauls, d. be charged by DC or AC power when available, e. produce AC power for his fast AA/AAA battery charger, if desired,
f. produce DC power for a mobile DC-powered battery charger that would recharge his small batteries during fire-fighting missions,
g. produce solar USB power for USB-powered devices and a solar cell phone charger as needed, h. provide durable, long-term independence from the power grid, and i. be silent. A portable solar panel-battery system was assembled that included the following components: a. reliable, safe, 11.1-volt, 4.24 amp-hour, extremely lightweight lithium battery pack with lightweight enclosure/bag, b. 5-10-20-watt extremely lightweight, folding, portable solar panel that remained outside the bag, c. small lightweight solar charge controller, d. 120-watt DC-AC power inverter for the AC-powered battery fast charger, e. 12-volt female DC socket for a DC-powered device,
f. a USB adapter to function as a USB solar charger, g. proper fusing and wiring, and h. MOLLE-compatible deployment pack in user-selectable color/camouflage.
The power system could deliver a maximum of 88 watts of power to the DC port and inverter for short lengths of time, 20 watts for as long as 2 hours, and was wired, fused, and electronically protected accordingly. Depending on the exact components included, the entire system weighed between 3 and 4 pounds. In good sunlight, it would take 3-4 hours for the solar panel to recharge the battery from empty to full, depending on the power of the solar panel. Of course, the system may be used to recharge MW’s smaller batteries when the system battery is less than fully charged. There is a USB adapter that plugs directly into the cigarette lighter socket, and has two standard female Type A USB charge ports, one that provides 1 amp of current, and the other that provides 2.1 amps of current for MW’s power hungry iPhone, iPad, Tablet, or other USB-charged device. If MW required added protection against damage, dust, or water, this same system could be enclosed in a waterproof hard case.
The portable solar power system powers up the AA/AAA/CR123 battery charger silently and repeatedly while on the go. When not in use, the portable system is stored with the remainder of the fire-fighting gear, and trickle-charged using an AC-powered battery charger until it is needed again.