So you’ve finally decided that you need a cordless impact wrench. The right impact is a great addition to anyone’s toolbox, while the wrong one could make the purchase useless. The wrong one could either be something that is far too overpowered for what you need it for (so long as you’ve got variable torque this isn’t too bad, but at the very least it’ll likely be heavier and bulkier than necessary), or underpowered (this is much worse, because it nearly makes the tool useless). This article I’ll be covering what to look for in a battery. How much power you need, what to look for in a charger, and what type of battery you need.
The most important aspect of an impact wrench is power. The whole point of an impact is to loosen those tough-to-get-off nuts and bolts, and if you don’t have enough power, you’re essentially left with an over-sized air ratchet. With cordless tools the power comes from the battery, and the key spec here is volts. Overall volts are the electric measurement for power. But more volts isn’t always better… but it does mean bigger (if your comparing two of the same types of batteries), so if you’re concerned about the size of your cordless impact, you may want to look for a battery with less volts.
How often will you be using your impact? And for how long? Are you the type that remembers to keep the batteries charged? Having a charger that quickly charges your batteries can be very important for some people. Some higher end cordless impacts have chargers that’ll have you up and running in 15 minutes, while older chargers will often take up to 3 hours for a single battery. If you’re going to be using your impacts for longer periods, or if you’re often on tight deadlines and can’t afford to wait for your batteries to charge, how quickly your batteries will charge is an important consideration Best Cordless Impact Wrench.
Finally, what type of battery is the best? Nickel based batteries are the older style, are less expensive, but heavier and bulkier. NiMH specifically will lose its charge quickly in the cold. Lithium Ion batteries have a much higher energy density than nickel based batteries, which means you can have the same amount of power in a smaller package (or alternatively you can have more power in the same sized package). However Li-Ion batteries are the most expensive. Odds are that if you buy a higher end cordless impact (which I urge you do to, the cheap ones just aren’t worth it), it’ll come with Li-Ion batteries, so this probably won’t affect which impact you buy, but just in case you are looking at older impacts, the difference between the batteries is important to know.
If you’re buying a new cordless impact wrench, keep in mind how much power it’s got (and how many volts the battery is), what to look for in a charger, and what the difference is between the different types of batteries.