There are a lot of devices out there that you can use as a “portable power pack,” but the best one for long road trips is a jump box. Although jump boxes are designed primarily to jump start cars, most of them come with at least one built-in 12 volt accessory socket.
Since the heart of every jump box is a sealed lead acid or gel pack battery, you can use that accessory socket to power anything that you might otherwise plug into the cigarette lighter socket in your car.
There are three factors that you’ll want to examine before you choose a jump box to use as a portable power pack:
1. battery reserve capacity
2. power outlets
3. other features
The battery reserve capacity is the most important thing to look at since it dictates exactly how much power you’ll be able to squeeze out of the device. If you want to power up a lot of electronic devices over the course of a long road trip, then you’ll want to find a portable power pack with the largest possible reserve capacity.
You may also want to consider buying two or more units if your trip is especially long, and it’s also worth keeping in mind the fact that a depleted power pack will be unable to perform its intended function. That basically just means that if your car battery does happen to go dead, and you’ve been using your jump box to watch movies on your laptop all night, you probably won’t be able to use it to jump start your car.
In terms of power outlets, most jump boxes come with at least one 12 volt accessory socket. If you want to power multiple devices at once, you can either buy a portable power pack that has multiple sockets or use an adapter that splits the single outlet into several.
Some jump boxes also come with built-in inverters. If you have laptops and other electronics that don’t have 12 volt chargers or power supplies, then a portable power pack that comes with an inverter is probably going to be your best bet. Although an inverter that's plugged into your car's electrical system will do the trick when the engine is running, it will quickly drain your battery down to nothing after the engine has been shut off.
Of course, it’s important to remember that even large jump boxes have pretty strict limitations, and you’ll be unable to recharge your portable power pack until you have prolonged access to electricity. Some portable power packs can be recharged via your car’s cigarette lighter when you’re driving, although that usually requires additional hardware.
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