Two hours after walking into the wild, your cell phone rings. You answer as the battery goes dead. Now what? Instead of returning to your vehicle, you can use your thermoelectric generator (TEG) to charge your cell phone by heating water for tea.

For those in the wilderness needing to charge a smartphone, GPS or tablet device via its USB port, a thermoelectric generator is the go-to resource. As the name implies, the thermoelectric effect converts heat to electricity (using solid-state devices). While thermoelectric generators will charge a device with a USB port, the charge time can take hours if the device’s internal battery is fully depleted. Small solar panels will also charge an internal battery., but it’s difficult to compare charge times of thermoelectric generators with those of solar panels because of cloud cover, panel size and efficiency.

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While water must be used in most thermoelectric generator during use,  this is not true for some like the CampStove from BioLite. This TEG creates electricity from excess heat produced by burning biomass like twigs and other foliage.

Thermoelectric generator

BioLite’s CampStove produces high heat due to its internal TEG-driven fan.

BioLite CampStove

Roughly the size of a 1-quart water bottle, the CampStove weighs 33 ounces. So it’s relatively heavy, but because users needn’t carry fuel, weight is less of a factor. The CampStove burns biomass, which works well in some regions. (Users will have to check local statutes regarding burning twigs and leaves in fire-prone areas.) In a desert or arctic environment, however, users will have to carry fuel or use a different stove. What differentiates the CampStove from most others is a thermoelectric-powered fan that improves combustion and increases heat output. After powering the fan, surplus electricity (2 to 4 watts at 5 volts) powers the USB port. The manufacturer claims that the average time to boil 1 quart of water at sea level is 4.5 minutes, making it comparable with most liquid- and gas-burning camp stoves.

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BioLite also makes the KettleCharge, a stovetop water-based generator that produces 10 watts – enough energy to charge tablets, smartphones, headlamps and water purifiers, making it a great outdoor companion and emergency partner.

Thermoelectric generator

PowerPot charging a phone using heat being produced by the VitalGrill.

Power Practical PowerPot 5

The 1-quart PowerPot 5 cooking pot with lid weighs 14 ounces. The TEG modules are encapsulated in the bottom of the hard-anodized aluminum pot, which means it has no moving parts. It charges handheld devices powered by internal batteries that have USB ports. The
USB cable features a silicone coating that can withstand temperatures in excess of 500 degrees Fahrenheit and intermittent contact with flames. The device has no heat source, so it can be used with any camp stove. I used the
VitalGrill stove to heat the PowerPot. The PowerPot 5 produces 1 amp of power at 5 volts (5 watts).

Thermoelectric generator

The compact FlameStower unit weighs only 10 ounces.

FlameStower

The lightest of the thermoelectric generators listed here, the compact FlameStower unit weighs only 10 ounces. When folded, it’s about the size of a television remote control. Like the preceding products, it charges a smartphone or any other device powered by internal batteries. The FlameStower provides 2.5 watts of power via a USB cable, meaning that it can fully charge a smartphone in 3.1 hours. Incredibly, it can charge while cooking on any flame source, even a campfire.

While these products are all different, they’re all quality models. Choose one based on its features, benefits and advantages, or consider where you will be using the system.

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Watts The Difference?

BioLite CampStove: 33 ounces/  5 by 8.25 inches/  4 watts at 5 volts

PowerPot 5: 14 ounces/ 4.5 by 4.5 inches/ 5 watts at 5 volts

FlameStower:  10 ounces/  2.25 by 7.75 inches/ 3 watts

For More Information

BioLite
biolitestove.com

FlameStower
flamestower.com

Power Practical
powerpractical.com

This article was originally published in the SURVIVOR’S EDGE Spring 2015 issue. Subscription is available in print and digital editions here.