The PiggyPower Ember USB Cell Kit is a compact, water-cooled thermoelectric generator kit designed to turn controlled heat into usable USB power. It is built for emergency lighting, battery bank charging, camping, blackout preparedness, off-grid testing, and real heat-to-electricity demonstrations. Includes Limited Workmanship Warranty and access to the PiggyPower Lifetime Service Rebuild Program. See our Warranty, Terms, and Service Policy for full details.
The Ember works by creating a temperature difference. Heat is applied to the hot side, water cooling removes heat from the cold side, and the unit produces USB output when the temperature difference is strong enough. This is not a battery, solar panel, or fuel generator. It is a solid state power cell that produces electricity from heat.
The unit includes 2 USB-A ports and 1 USB-C port, allowing support for up to 3 USB powered devices at once. Each USB port supports up to 3 watts, for up to 9 watts total shared USB output when the heat source and water cooling are strong enough. At the 32°F, or 0°C, cold side benchmark, the Ember begins reaching its maximum shared USB output range at roughly 240°F to 250°F hot side temperature, about 116°C to 121°C. Total output is shared between connected devices and depends on heat source strength, water temperature, water flow, ambient conditions, and the type of device being powered.
For the base kit, a candle is a simple recommended starting heat source because it is easy to use and easy to demonstrate. A candle can power efficient USB lighting and may add meaningful charge to compatible USB devices over the course of an emergency, but do not expect fast charger performance from a single candle. Stronger controlled heat sources such as Sterno, camp stoves, propane burners, hot plates, wood stove surfaces, charcoal setups, or similar stable heat sources can produce stronger output when paired with good water cooling and safe temperature control.
Each Ember includes a built in voltmeter for a simple live operating reference. When USB devices are plugged in and the voltmeter is lit, the general rule is to keep the display below 5.0 volts during operation. If the voltmeter is not lit, that is normally fine. It usually means the unit is not being heated strongly enough to wake the display or produce stronger USB output yet. You still need to pay attention to your cooling water temperature and follow the operating instructions in the manual.
The USB ports are mounted externally so you can plug devices directly into the unit without opening the housing or disturbing the electronics.
What’s included:
1 fully assembled PiggyPower Ember USB Cell unit
2 USB-A output ports, 3W each
1 USB-C output port, 3W
Built in voltmeter
Thermometer
USB powered 1 watt to 3 watt water pump
Short hose connections for inlet and outlet setup
10 ft of additional hose
Basic setup and operating instructions
Heat source, candle, Sterno, fuel, bucket, water container, phone, USB cables, charger cables, battery bank, and other external USB powered devices are not included unless specifically shown in the included items photo. Bucket shown in demonstration photos is for demonstration only.
Water cooling is required during operation. Cooling is not optional. The cell needs heat on one side and water cooling on the other side to produce useful power. If the cooling side gets too warm, output will drop. If the unit is heated without proper cooling, it can be damaged. Do not allow the cooling side to run dry while heat is being applied.
Use only stable, controlled heat sources. Always keep the plastic housing, USB ports, wiring, and hoses away from direct flame. Use only on a stable, nonflammable surface. Do not leave the unit unattended while heat is being applied.
Some USB devices are more demanding than others. Some phones may charge slowly, cycle on and off, or require stronger input depending on available output. USB lights and battery banks are often the easiest loads to run because they are more forgiving than some phones.
Important operating notes:
Water cooling is required.
Use the included thermometer to monitor cooling water temperature.
When USB devices are plugged in and the voltmeter is lit, keep the display below 5.0 volts.
If the voltmeter is not lit, that is normally fine and usually means the heat source is still too low.
Do not operate unattended while heating.
Do not let water enter the USB ports or electronics.
Do not submerge the unit.
Do not place hoses, wiring, USB ports, or the housing near direct flame.
Do not expect fast charger performance from a candle.
Use stronger controlled heat and good water cooling for higher output.
Follow the full setup and safety instructions in the included manual.
The PiggyPower Ember USB Cell Kit is designed for USB powered devices, emergency utility use, demonstrations, and off grid experimentation.