Monday , May 20 2024

The Lowdown on Milwaukee Batteries

Cordless tools have long moved on from being unreliable, gutless stand-ins to their corded counterparts. Significant improvements in power output and runtimes mean they’ve become the preferred choice for any self-respecting tradie or DIY-er. Combined with the added benefits of maneuverability, mobility and range and big, beefy batteries, users get a decent day’s worth of constant power, without being tied to a power point. In fact, all major toolmakers have made the shift from corded to cordless, offering entire lineups suited to any type of job.  

One of the first companies to bite the cordless bullet was American tool giant Milwaukee. With rare exceptions, their power tool range now consists almost entirely of cordless tools all powered by batteries with some of the longest runtimes on the market. For power-hungry tools like circular saws or hammer drills, this is a game-changer. You get all-day usability at a constant output, without straggling cords or missing outlets to add to the hassle. And behind all that convenience is a Milwaukee battery that you can use across the whole range of over 150 cordless tools.  

Cordless Power Tool Batteries – The Basics 

Close-up of Milwaukee batterie M18


The two major things to look at when buying a battery for your cordless tools are power and runtime. Power correlates to Voltage ratings, and two standard outputs are 12V and 18V. The first will be more than enough to power small tools like drills, even for more challenging tasks. For tools that need more bite, it’s 18V all the way, though even a 12V might suffice for shorter bursts of power.  

Runtimes or battery capacity is stated in Ampere-hours, and the bigger the number the longer you can use the tool. This was a major weakness with the first cordless batteries, but new tech focussing on power use and efficiency means today’s batteries don’t fall behind corded tools in terms of power supply. You won’t have to stop mid-way through work to charge batteries. Improvements in both areas are the reason behind the widespread acceptance of cordless tools.  

Other considerations to get the most out of your purchase are life cycles, charging times, and to a lesser extent self-discharge. Leading brands like Milwaukee have invested a lot of R&D to produce batteries that will last for years to come without gradual loss of power. Charging times are also much shorter with bettered chargers, able to charge from 0 to 80 per cent in a matter of minutes. And with the switch to Li-Ion, initial quibbles like advanced self-discharging in (Nickel-based) batteries not in use, as well as memory effect (in short, inability for a full charge) are now history.  

The Milwaukee Battery Lineup – Which Battery is Right for You? 

Close-up of working with cordless Milwaukee drill


Not all power tools are the same. Nor are the batteries that power them. Some tools require shorter bursts of power and more of it (drilling into thick concrete for instance), while others need constant output over prolonged periods. Milwaukee’s extensive tool lineup is served with batteries in 12 and 18V power ratings, and four distinct product lines.  

The M12 line is compatible with up to 100 different cordless tools, ranging from drills and grinders, nailing guns, impact ratchets, sanders and more. Capacities range from 2Ah, meaning consistent output for two hours, to batteries in 6Ah for tasks requiring a little more attention. Milwaukee here provides optimal efficiency with monitoring tech to improve discharge levels in individual cells separately, in effect allowing for prolonged use and at the same time, extending battery life cycles.  What’s specific about M12 batteries is their small size and lightweight without compromising on overall power and capacity for the intended task.

M18 batteries were introduced as the company completed its gradual shift to include cordless tools across all power tool categories. Today, Milwaukee has over 150 tools compatible with its 18V M18 Red Lithium batteries, and these are at the core of the company’s focus on professionals and DIY-ers. They’ll provide considerably more power and considerably larger tools.  

Compact, Extended Capacity, High Demand or High Output? 

Close-up of Milwaukee batteries and a charger


These Milwaukee battery lines define what you need and can get out of your cordless Milwaukee tools. In short, Compact (CP) batteries are mostly the M12 type, feature in smaller tools like impact drivers, palm sanders and nailers, and are favoured for being lightweight and with fast charging times.  

Extended Capacity (XC) is the bread-and-butter battery for most users who rely on longer run times. These feature in some M12 batteries, but the M18 line is well catered to. They run small to medium tools like grinders, drill drivers and saws.  

High Demand (HD) Milwaukee batteries are great for more demanding tools, like chain and mitre saws and offer decent run times. Newer additions are High Output (HO) 21700 batteries, with improved cell structure and chemistry and these are found across the CP, XC and HO lines in both 12 and 18V iterations. They offer the longest run times (from 3 to 12Ah), better power delivery and improved heat management. Another major benefit is much quicker charging. 

One thing to note is the ‘FUEL’ moniker designed specifically for brushless Milwaukee tools. These better integrate with tools using proprietary tech to maximise efficiency, capacity and power, while lowering heat levels and extending battery life cycles.  


To charge batteries, a Milwaukee charger does the job quickly and safely. There is a range of different chargers depending on the battery and your needs – single, dual, sequential, vehicle and chargers that can top up both M12 and M18 batteries in a single go.