All of my employees and I were sitting in our trucks eating lunch when the OSHA inspectors arrived on the commercial job site, which was a two-story addition to a nursing home. Talk about fear — the other trades and general contractor’s employees about had a coronary! Violations abounded: Opening in the concrete deck for stairs that weren’t yet built and no barrier was present; workers missing hard hats; improper footwear; ladders that needed repairs; and, of course, lots of extension cords with taped-over nicks in their jackets and plugs missing the grounding pin.

That was decades ago: Long before any contractors had cordless tools that could handle the rigors professional contractors face on job sites. My first cordless tool was a Makita drill that I purchased in 1978 with a 7.2-Volt NiCad removable battery and a separate 120-volt charger. The main drawbacks were the battery needed to cool down before recharging and if you did not fully discharge the battery, its memory would reduce the available runtime, rendering it useless eventually. The advantage of the NiCad was it could be recharged up to 1,000 times if treated properly. Its chuck key was relatively small with a tendency to slip, which resulted in painful pinching when fingers got caught between the chuck/key. The useful time was fairly limited, which resulted in my taking it back off of my work truck, and it was relegated to home projects. For the time being, all my tools would remain corded.

When I ventured out on my own in 1979, I purchased most of the tools needed at an auction for a going-out-of-business plumber. In the mix was a very old Hilti hammer drill that still works. The local Hilti salesman became a friend when our oldest son dated his daughter. Hilti had a contest one year to see who had the oldest Hilti tool, and we submitted my hammer drill. Hilti was stumped and could not date my hammer drill!

The Colt .45 automatic pistol inspired Alonzo G. Decker, in 1914 to improve upon power drills by incorporating a pistol grip and trigger for one-handed control. No background check required! Decker is better known as the partner of S. Duncan Black, who together started up their business in a small machine shop in Baltimore, Maryland in 1906, but didn’t formally become Black & Decker until 1910. When they first came out with 18-volt cordless tools, I purchased a kit that had a drill, skill saw, sawzall and flashlight. Once again, the battery runtime was disappointing and, over time, they eventually quit working. I moved them to my home shop and upgraded to Ni-Mh 3600mAh battery packs (more on battery types and mAh follows below).

Many folks credit Makita with inventing the first cordless drill, but it was actually Black & Decker that designed the first cordless drill. However, it was Makita that first offered the cordless drill to the general public.

If you had told me 15 years ago that most of our powered tools would be cordless, I would have thought you had gone ‘round-the-bend. How things have changed! Voltage and battery run-hours on a single charge have both increased exponentially. My cordless hand tools, for the most part, are 20-volt and 4-Ah batteries. I also have a 36-volt small chainsaw, which is arguably the most dangerous tool I have. Absolutely no safeties, so users beware. As Mike Rowe intones: Safety third! But my big-boy chainsaw, pole saw, pole hedge clippers and blower all operate off 40-volt 2- and 4-aH batteries. My 2-cycle gas chainsaws have not been used in years. Convenience and less fuel/oil mess simply mean I prefer the battery-powered tools now.

Let’s break down what voltage, Ah, and battery type do for you.

Voltage: The higher the voltage, the more power delivered to the business end of the tool. Heavier duty usage will need a higher voltage. My 40-volt batteries can handle tougher jobs than my 20-volt batteries.  

Amp-Hour (Ah): This is the amount of battery charge that can be delivered in one hour. If, for example, my big-boy chainsaw draws 2-Ah under actual usage, then I can expect 2 hours of run time with my 4-Ah battery if it’s fully charged. Loads can vary, so actual runtime is not a hard and fast number. mAh is milliampere-hour, and my 3,600 mAh Makita battery would, when new and fully charged, equal 3.6-Ah.

When we landed the huge Wellspan York Hospital snow-melt job with its 14 miles of PEX tubing, we purchased two battery-powered rebar tie tools that effortlessly triple-wrapped the PEX to support and twist-tied the end in less than a second. The tools reduced our time by a margin wide enough to more than offset the $5,000 expense and saved our backs.

Four basic battery types:

Li-Ion (Lithium Ion) is the most popular and widely used today. It’s the same type of battery utilized in a Tesla, but on a much smaller scale as the average Tesla battery weighs 1,000 pounds! Li-Ion cordless tool batteries pack a punch (high power and small size), high Ah ratings, can be recharged time and again, and do not suffer memory loss if not fully discharged. The ability to toss one on the charger anytime can be a huge advantage — like during breaks or over lunch — and get you through a day’s work without the need to keep extra batteries on site.

Ni-Mh (Nickel-metal hydride) are mostly used in electronics where high current in short bursts is required. They have a relatively short life of three to five years.

Ni-Cad (Nickel-Cadmium): Once quite popular, but far fewer used today because Li-Ion batteries are more prevalent and the Ni-Cad batteries are limited to slightly over 2-Ah. They can suffer memory loss if not fully discharged regularly. For my Makita drill, I used a paddle bit on a piece of scrap wood and ran it to full discharge.

Lead/acid: Unless you have an inverter you can attach to your car/truck 12-Volt lead/acid battery to power up your corded tools, when was the last time you saw a tradesperson dragging around a lead/acid battery for their 12-volt tools? Confession here: we used confined space entry blowers by attaching a portable inverter to our truck batteries and I use a deep-cycle lead/acid battery for my sporting clay thrower.

Today, even sewer machines are going cordless. When we landed the huge Wellspan York Hospital snow-melt job with its 14 miles of PEX tubing, we purchased two battery-powered rebar tie tools that effortlessly triple-wrapped the PEX to support and twist-tied the end in less than a second. The tools reduced our time by a margin wide enough to more than offset the $5,000 expense and saved our backs. The same thing happened for a large Pro-Press PEX job with two battery-powered expanders. Then there are the press tools where we started with the original corded RIDGID press tool, which is a tank compared to our battery-powered RIDGID press tools. Digital Freon gauges and superheat/subcooling automatically calculated. pH meters and a host of other tools that were either always battery-powered or became so over the past two decades.

Change is constant and that keeps your job from being boring!

The best part: No cords for OSHA to ding you on if they show up for an inspection unannounced.