Choosing a Jump Starter, Jump Box, or Battery Charger

The two main types of jump starters out there are jump boxes and plug-in units. Jump boxes are essentially just sealed, maintenance-free batteries that have jumper cables attached to them, and plug-in units are basically battery chargers that are capable of delivering the huge burst of amperage that your starter motor pulls when it’s turning the engine over.

If you only ever need to jump-start your car at home, then a combo charger/jump starter unit is a good choice. Otherwise, you’ll want to look at jump boxes. Of course, that’s only a very small part of the big picture.

Plug-in Jump Starters and Chargers

car jump box vs charger
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Most trickle chargers provide between 2 and 10 amps, and a lot of them have multiple settings. This is due to the fact that it’s typically better for battery life to provide some (or all) of the charge at slower rate via a lower amperage, but it isn’t always convenient to wait around for a 2 amp trickle charger to do its job. In that same vein, some battery chargers have a “start” setting that delivers a much higher amperage. Depending on how dead the battery is, you may even be able to turn the charger on, select the “start” setting, and immediately crank the engine.

The main benefit of buying a plug-in jump starter/battery charger is the charging part of the equation. Although the instant-start you get from the “start” setting of some chargers or a jump box is convenient, it isn’t that great for your charging system. Since modern alternators aren’t designed to charge completely dead batteries, forcing one to do so can shorten its effective lifespan. If you have a charger on hand, and you can wait a while for it to do its job, then you may save yourself a costly alternator repair bill somewhere down the line.

Of course, the main drawback of plug-in units is pretty self-evident: they have to be plugged in. Although some plug-in starter/charger units are actually pretty small and portable, they just don’t work if you can’t find somewhere to plug them in.

If you do decide to get a plug-in unit, then you’ll want to look for one with features like:

  • Multiple charging modes (i.e. 6V, 12V)
  • Multiple amperage settings (i.e. 2/10/75A)
  • Float charge option

Jump Boxes and Portable Power Packs

The other main type of jump starter is typically referred to as a jump box since this type of unit is basically a battery in a box. A typical jump box consists of a sealed, maintenance-free battery that is permanently attached to a set of heavy-duty jumper cables, and the whole thing is contained in a convenient (typically blow-molded plastic) package.

Unlike plug-in units, jump boxes can’t charge a dead battery. However, they are portable, and they are capable of providing the necessary amperage to start a car that has a completely dead battery. That makes a jump box the best choice for anyone who ever has to jump-start their car away from home. As long as you choose a unit with a big enough battery, and you keep it charged up, you can carry it around in your trunk and never have to worry about being stranded with a dead battery.

The main downside of using a jump box is that driving around with a dead battery isn’t very good for your alternator. If you make a habit of jumping your dead battery with a jump box and then just driving around town, you may artificially shorten the lifespan of your alternator. The issue is that modern alternators require a 12V input from the battery to function properly, and a dead battery can’t provide that. In addition, it takes a lot more work to charge a dead battery than to maintain a charge, and alternators are really only designed with charge maintenance in mind.

With that said, a good jump box can be a real lifesaver, and you can help reduce the potential damage to your alternator by driving around with your dead battery as little as possible. If you have a battery charger at home, then you should make sure to use it as soon as possible. If not, you may want to consider enlisting the help of a friend or neighbor or even leaving your car with your mechanic to have the battery charged. If you’re not sure why it went dead in the first place, that’s also a good opportunity to have charging and electrical systems checked for issues.


Top 3 Portable Jump Starters

Portable Jump Starter Features

If you do decide to buy a portable jump starter, then some of the features to look for include:

Plug-in Jump Starters vs. Portable Jump Starters

Since plug-in jump starters and portable units each have their own strengths and weaknesses, you may actually want to consider getting one of each. If you can only afford one, then a portable unit is probably going to be the way to go, simply due to the fact that you can use it wherever you are. However, pairing a portable unit with a charger/jump starter means that you’ll be able to charge up your battery once you get home, which can save you both money and headaches in the future.

Making Your Own Jump Box

Since a jump box is basically just a sealed lead acid battery with built-in jumper cables, it’s technically possible to make your own (though buying a jump box is usually cheaper than building your own). Some repair facilities do this by strapping several batteries to a hand truck, wiring them in parallel with heavy gauge cables, and then connecting a good pair of jumper cables. This is a great setup that provides a ton of reserve capacity, but it isn’t exactly portable.

If you want to make your own jump box, the best (and safest) way is to obtain a sealed, maintenance-free battery with a high cranking amps (CA) and cold cranking amps (CCA) ratings, in addition to a battery box big enough to fit it inside. The battery box is an important part of the equation due to the fact that although sealed lead acid batteries usually won’t leak if they tip over, they can (and often do) leak due to age, overcharging, and other factors.

Of course, the last thing you’ll need to make your own DIY jump box is a set of jumper cables. You don’t have to permanently attach them to the battery box, but you can if you want to.

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