Shop Talk

Get to Know Your Power Tool Battery: Clarifying Battery Myths and Misconceptions

  • There are many stories floating around the tool community about what is and isn’t good maintenance for your batteries. As all craftsmen know, a battery is an important investment, and it is equally important to know how to protect and maximize that investment. The following information is meant to dissolve or clarify some of these stories, myths, and misconceptions to help you to better know and understand your batteries.


    — Frozen Batteries:

    Don’t EVER put your batteries in the freezer! Sometimes craftsmen damage their batteries while trying to keep them better maintained – I can’t even begin to specualte where the “better batteries come out of the freezer” rumor came from, but it is entirely ludicrous. The absolute best way to keep your batteries at peak performance is to keep them in a temperate and dry place. Freezing your batteries will not help them, in fact, this can be very harmful, as in, it will ruin them. Bringing your batteries in-doors whenever possible is a good way to ensure they are in a dry and temperate environment. You always want to keep your batteries at a comfortable room-temperature.

    — The Higher the Voltage, The Better the Battery:

    This is not always true. It is both the tool, and battery that effect your tool’s performance. Specifically, the tool’s motor, transmission, and other power producing elements have a tremendous effect on how well the battery transfers energy into the tools working parts. The quality of of the magnets in the tool’s motor, its gears, and the chuck that in turn transfers energy to the tool bit or blade are all contributing factors to the efficiency of your tool. Essentially, everything from the tool itself, to your bits or blades effects how well your battery can transfer energy into your tool. Although higher voltage batteries are more powerful, it is best to ensure you are using high-quality tools and accessories to achieve the highest performance, and greater quality work.

    — Battery Memory Effect:

    Battery memory effect, or lazy battery effect occurs (especially in Nickel Cadmium batteries) when a battery becomes unable to accept a complete charge because it has been repeatedly recharged without first being fully depleted. The term memory effect comes from the sense that the battery “remembers” how much charge was depleted, and begins to accept only that much energy from the charger. This defect is becoming less and less frequent as battery technology continues to improve, and as it turns out, these days it can prove more detrimental to your battery to entirely deplete its energy storage before recharging it. This can damage to the battery’s cells preventing them (similarly) from holding a full charge. Ultimately, your battery may begin running on one or two less cells than it’s meant to, this decreases both battery power and battery life. Essentially, the best time to charge your battery is when it stops performing well enough to finish your jobs smoothly and professionally. When your battery begins to notably slow, charge it.

    — All Chargers Are Created Equally:

    This is far from true. Generally, professional chargers will shut off after the battery has been completely charged. Less efficient chargers, on the other hand, keep forcing current through fully charged batteries. This continual charge causes a dangerous amount of heat build-up and decreases the overall life of the battery. In short, be certain you are using a high-performance battery charger, and for precautionary purposes, pull the battery off your charger once it has been fully restored.

    — Rebuilding Your Batteries:

    Whether or not batteries should be rebuilt remains an entirely ambiguous subject (but they shouldn’t). When having a battery rebuilt, it is generally impossible to know if the servicing party has used recycled cells to refurbish your battery. This may not be worth the risk, especially considering that purchasing a new battery costs about the same as rebuilding one. The best option is to take your old batteries to a service center for recycling, and buy a new, factory certified battery.