Dernord 12V 300W Immersion Heater Submersible Water Heater Element Stainless Steel Heating Element with 1 Inch NPT Fitting Double U Type

I replaced the 120v element in a Kuuma heater with this unit. Ran 8 gauge power cable to it and it does work. But it takes forever to heat a 10 gallon water heater from cold. Like 6 hours. The 120v element heated the tank from cold in 45 minutes. Once hot it maintains temp okay. Each cycle is about 1 hour. That being said its drawing 28 amps during that time. Overnight that depletes 40% of my 600ah battery bank. Not what I was hoping for. At 28 amps I really wish this got way hotter. I cannot decide if this is performing better than when I ran the 120v element off my inverter. I believe overnight depletion is around the same. I am really interested in trying it at 24 volts, but that an experiment for future me. So if your using this in a vehicle, and that vehicle is running the engine every day you should be fine. And 28amps is way less stress on the batteries than 160amps is from an inverter. Just plan you showers accordingly as the recoup time is LONG. I will update long term performance a few months from now.

Works but it isn't 500 watts. Meter rates it at around 640 watts. It works just fine but I wasn't expecting the extra 140 watts on my solar system.. Would buy again

This is a great option for heating water in my car rooftop solar tube. Fit is excellent. ABS 4x4x2 fitting with PVC adapter/reducer and threaded galvanized reducer. I test ran with one element connected. It drew 175 watts. When I connected the second it drew 350 watts. Thought folks should know actual power usage.

I measured the element with connecting bars attached. Ohms measured 0.5 ohms, 12 V/0.5 ohm=24 amps, 24x12=288 watts. This will give a decent amount of heat to keep water from freezing.

I have used these for years and never had one fail. With the two elements, they can be configured for half-load (one element), full load 12V (factory config with parallel jumpers) or full load 24V (move jumpers to series the elements). As such, they are perfect dump loads for solar and wind turbine use and can store energy as hot water. The 1" NPT fittings fit many common water heaters.