Keep your battery running at full power even when the temperature drops—these heaters warm batteries quickly without overheating them. They fit most automotive and marine batteries. Made from oil- and acid-resistant materials, they stand up to the harsh conditions under the hood of your vehicle. Add a timer switch to automatically turn them on and off at a set time and day.

Band heaters are best if you want to move the heater from vehicle to vehicle or only need to heat your battery every now and then. They heat faster and more evenly than sheet heaters, and they’re simpler to install—just wrap them around your installed battery. However, you have to take them off before running your vehicle, so you can’t leave them on permanently.

Sheet heaters are best when you need to heat your battery frequently. They heat from underneath, so you’ll need to remove your battery to install them. Once installed, you can safely leave them inside your vehicle as it runs. Just make sure to secure the cord so it doesn’t get caught on any moving parts.