Don't let LifePO4 Batteries Freeze

This little unit can be used with either AC or DC. It is very easy to connect and use and is ideal for use with heating elements. 

You can use any 12v heat pads to work with your W1209 thermostat and i tried these and they are inexpensive. They come with a switch but don't use that as the relay is the control.

 Voltage: DC 12V. Power: 20w. Heating Temperature: 120-150℃. This rubber heating pad has excellent dielectric strength, fast heating and perfect heat transfer efficiency, which can provide heat quickly 

 Voltage: DC 12V. Power: 30w. 50 x 90mm

100% brand new and high quality
*Safe, waterproof and moisture-proof.
*Made of high-quality materials, more durable
*Made of soft silicone rubber, reducing energy costs for heating the hive
*Feed consumption can be greatly reduced when using electric heating in winter
*Fast heating, uniform temperature, high thermal efficiency, good toughness
*Easy to use, safe, waterproof and long service life
*Suitable for all kinds of automobile fuel tank, water tank, battery antifreeze insulation
 

If you have a 24 volt battery system and want to use 12v heating elements you can use this device to reduce the voltage to 12 volts

• Thermostat Control] Built-in thermostat control, this heating pad will turn on at 45°F ( ±5°) and turn off at 86°F (±5°F) automatically. It will help prevent your tank from freezing but won’t drain your battery.
• [✅High Efficiency] Designed for 12V DC application, its power is 60W. This pad work efficiently up 50 Gallon Holding tanks. Easy to install with Self-adhesive design and 3mm thickness foam insulation prevents heat from disappearing rapidly.

These are really good for keeping things warm. I use one under my own lifepo4 battery bank and its very economical to run at only 40W

 Key features include:
° 3 heat settings so you can adjust for the perfect heat level
° Machine washable - Simple detach controller and throw in the machine for a clean wash
° Controller included to control your heat settings
° High-quality 450gsm polyester designed for long lasting use
° Indicator light notifies you when your heated blanket is on 

Quantity and Size: you will get 8 pieces of silicone heating pad, the size is about 3.15 x 3.94 inches/ 80 x 100 mm, the thickness is 0.06-0.08 inches/ 1.5-2 mm, and the maximum temperature resistance is 200 degrees Celsius

• Product Parameters: working voltage: DC 12V; Power: 25W; Power tolerance: ±5%; Insulation resistance: 50 MΩ; Compressive strength: 1500v/5s, this rubber heating mat has good electrical strength, heat transfer efficiency and resistance stability
• Easy to Use: there is glue on the back of the tank heater pad, just tear off the layer and directly attach it to the surface of the heated object; Note: make sure that the surface of the heated object is clean and no dust before sticking, and apply it from one side to the other during sticking; Scrape the surface of the heating pad with a ruler or something while sticking, to ensure that it is tightly stuck without bubbles

Model: W1209 With Case
Dimensions: 48.5 * 40mm
Temperature Control mode: ON / OFF
Temperature Range :-50 - 110 degree centigrade
Resolution: When temperature is 0.1 degree, the resolution is -9.9~99.9, other temperature segment is 1 degree.
Control Accuracy: 0.1 degree
Hysteresis Accuracy: 0.1 degree
Refresh Rate: 0.5s
High Temperature Protection 0 - 110 degree centigrade
Supply Voltage: DC 12V
Static Current: Less than 35MA, attract current less than 65MA
Output Voltage: DC 12V
Output Power: 20A relay
Measurement Input: NTC (10K 0.5%) Waterproof Sensor
Environmental Requirements: -10 - 60 degree centigrade; Humidity 20% - 85%