I'm looking to use a peltier cooler backpack that typically plugs into a car's 12V cigarette lighter socket, but I want to be able to power it using a battery while I'm out. I've got a 12V 9Ah LiFePO4 battery brick, and I'm considering getting something similar. I want to run and charge the cooler simultaneously while it's plugged in the car, but I'm not sure how to set it up. My main worry is that the battery and cooler shouldn't exceed the 160W limit of the cigarette lighter socket since LiFePO4 batteries can draw a lot of current. Any suggestions on how to make this work?
3 Answers
Your cooler should only pull the power it needs, which usually isn’t much unless it's struggling to cool. Just double-check your car’s fuse ratings, as most can handle around 10 amps. That said, if your cooler is a power monster, it might drain the battery too quickly. I suggest testing it out and keeping an eye on the heat to make sure nothing’s overheating.
Make sure you have a proper Battery Management System (BMS) for your LiFePO4 battery; it’s crucial for safety. If your battery pack has a built-in BMS, then you’re good to go! No need for a buck converter since both the cooler and battery are 12V. Just plug it in and try it out.
You shouldn’t worry too much about the load drawing more current than it needs. The cooler will only pull what it requires, regardless of how much current your LiFePO4 battery can deliver. Just ensure the connections are good and that everything is rated for the correct voltage.
Just remember, the battery does act as a load while it's charging. Keep that in mind!
Exactly! But don't forget to monitor the cooler's power draw, just to ensure your battery isn't overloaded.