12 Volt 300 Watt 9 3/8 Inch DC Submersible Water Heating Element

I bought this to use excess solar power to heat my sailboat's 6 gallon Seaward hot water tank. With the battery charging at 14v, it uses about 11 amps (12v DC) at 150w. According to the description, 2.4705 watts heats one gallon one degree in one hour. So a 150w element heats one gallon about 60* in one hour, or heat a 6 gallon tank about 10* in one hour. That comports with my experience. I have 700 watts solar on my boat, and on sunny days, by noon I often have almost a full charge. I run a150w element for about 3 hours, and it heats the water up nicely on warm days. Needs a little more if the water starts off colder.To install, I removed the old AC element (hint: buy a tool for this at a hardware store for $10) and screwed in this DC element. I hooked the elements' terminals to the battery, with a switch to run one element (150w) or both (300w; which heats the water in half the time, which I use when plugged in and have dock power to supply the battery). I set up a standard rotary timer [https://www.amazon.com/gp/product/B003A41UZM/ref=ppx_yo_dt_b_asin_title_o07_s01?ie=UTF8&psc=1] with an on/off switch into the circuit via a relay [https://www.amazon.com/gp/product/B07T35K8S2/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1] to turn the circuit on and off. Since this element does not have a temperature switch, I use the timer to prevent over heating the water.I'm very happy with this set up. On reasonably sunny days, I don't have to run the engine to get hot water.

Happy with product..Quick shipping