Milwaukee M18 Batteries: 5.0, 9.0, 12.0, and Other Models
Milwaukee M18 batteries are intended for powering a long list (150+) of compatible Milwaukee M18 cordless tools, allowing users to power all of their tools using just a few standard batteries. Such practice also decreases the price of every purchased tool since it can be bought as a "bare tool."
Milwaukee M18 batteries differ in capacity and internal construction. Still, they all feature a fuel gauge, which allows the users to check the remaining capacity, and the built-in Battery Management System (BMS), which monitors the battery and protects it if required.
Published: August 22, 2022.
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Intro To Milwaukee M18 Battery System
Milwaukee M18 battery system is a set of lithium, power fade-free batteries designed to power a broad range of compatible Milwaukee M18 cordless tools and to be recharged using various compatible Milwaukee M18 lithium battery chargers that also often double as a carrying rack for a larger number of batteries.
Milwaukee M18 batteries feature a nominal voltage of 18V and 20+V maximum charging voltage and are at least comparable with 18-20V lithium battery systems from other renowned cordless tools brands.
Most popular models of Milwaukee M18 batteries feature nominal capacity in the 2.0 and 12.0Ah range, come with a fuel gauge (remaining onboard capacity tester), an intelligent Battery Management System (BMS) that monitors the battery and protects it from unwanted events, can operate in very cold weather (down to 0°F/-18°C), etc.
For short, Milwaukee M18 tools, supported by Milwaukee M18 batteries, are one of the most popular residential and professional cordless tools systems.
Here is the short list of Milwaukee M18 batteries with their most important features and specifications.
Milwaukee M18 Compact REDLITHIUM Battery Pack (48-11-1815)
Milwaukee M18 Compact REDLITHIUM Battery Pack (48-11-1815) features a nominal voltage of 18V and a nominal capacity of 1.5Ah.
Physical dimensions of the battery are 4.5 x 3.2 x 2.2 inches (~11.4 x 8.1 x 5.6 cm) and it weighs ~0.95 pounds (~0.43 kg).
With its 27Wh of stored energy, the Milwaukee M18 Compact battery is generally used for powering smaller tools (screwdrivers, drills, and similar) in tight and narrow locations.
Like all other Milwaukee M18 REDLITHIUM batteries, the Milwaukee M18 Compact battery features an onboard fuel gauge, intelligent BMS that can communicate with tools and chargers, durable construction, etc.
For the most up-to-date offers and prices, feel free to check the Milwaukee M18 Compact REDLITHIUM Battery Pack (48-11-1815) Amazon link (link opens in the new window).
Milwaukee M18 REDLITHIUM CP2.0 Battery Pack (48-11-1820)
Milwaukee M18 REDLITHIUM CP2.0 Battery Pack (48-11-1820) is another rather compact Milwaukee M18 battery pack, featuring physical dimensions just slightly larger than the Milwaukee M18 1.5Ah battery.
Milwaukee M18 CP2.0 battery is able to store ~36Wh of energy and release it when needed.
Construction is very durable, with increased water protection - water is routed away from the onboard electronics and out of the battery pack.
Like all other Milwaukee M18 batteries, the Milwaukee M18 CP2.0 battery also features a battery charge indicator.
Milwaukee M18 CP2.0 battery stores 33% more energy than the 1.5Ah battery, with just a small increase in weight, making it one of the most popular Milwaukee M18 battery models.
For the most up-to-date offers and prices, feel free to check the Milwaukee M18 REDLITHIUM CP2.0 Battery Pack (48-11-1820) Amazon link (link opens in the new window).
Milwaukee M18 REDLITHIUM HIGH OUTPUT CP3.0 Battery Pack (48-11-1835)
Milwaukee M18 REDLITHIUM HIGH OUTPUT CP3.0 Battery Pack (48-11-1835) is designed with high output in mind, allowing a relatively compact and lightweight battery to power larger, energy-demanding tools without adverse effects on the battery itself.
Milwaukee M18 REDLITHIUM HIGH OUTPUT CP3.0 Battery Pack features physical dimensions of 5.31 x 3.3 x 2.31 inches (~13.5 x 8.4 x 5.9 cm), and it weighs only 1.33 pounds (~0.6 kg) which isn't much for 18V 3.0Ah battery being able to store ~54 Wh of energy.
For many people and DIY enthusiasts, a pair of Milwaukee M18 CP3.0 batteries combined with a rapid battery charger is all they need to power their Milwaukee M18 cordless tools constantly.
Milwaukee M18 CP3.0 battery also features intelligent BMS, battery charge indicator, robust construction, water protection, etc.
For the most up-to-date offers and prices, feel free to check the Milwaukee M18 REDLITHIUM HIGH OUTPUT CP3.0 Battery Pack (48-11-1835) Amazon link (link opens in the new window).
Milwaukee M18 REDLITHIUM XC Extended Capacity Battery Pack (48-11-1828)
Milwaukee M18 REDLITHIUM XC Extended Capacity Battery Pack (48-11-1828) is designed as a battery pack offering a 50% larger capacity (3.0Ah) than the CP2.0 batteries.
Milwaukee M18 REDLITHIUM XC Extended Capacity Battery Pack (48-11-1828) comes with all features that a good Milwaukee M18 battery has, including durable construction, intelligent BMS, and charger tester, low-temperature construction, etc.
However, this battery is perhaps not the best suited for high-demanding tools and applications, at least not as the Milwaukee M18 High Output CP3.0 battery.
For the most up-to-date offers and prices, feel free to check the Milwaukee M18 REDLITHIUM XC Extended Capacity Battery Pack (48-11-1828) Amazon link (link opens in the new window).
Milwaukee M18 REDLITHIUM XC4.0 Extended Capacity Battery Pack (48-11-1840)
Milwaukee M18 REDLITHIUM XC4.0 Extended Capacity Battery Pack (48-11-1840) is an 18V 4.0Ah power fade-free lithium battery able to store 72Wh of energy and to power a broad range of Milwaukee M18 energy-hungry tools and devices.
Milwaukee M18 REDLITHIUM XC4.0 Extended Capacity Battery Pack (48-11-1840) features an intelligent BMS that is able to communicate with both the tool and the charger and protect the battery from extreme conditions that may harm the battery.
Also, the battery comes with a fuel gauge, strong construction, low-temperature operation, high-vibration resistance, etc.
Although this is an excellent battery that offers 100% more capacity than 2.0Ah batteries and 33% more capacity than 3.0Ah batteries and is able to power a broad range of tools and appliances, many Milwaukee M18 owners go for XC5.0 batteries instead of XC4.0.
But, if the capacity and the weight of XC4.0 fits your needs, feel free to go for XC4.0 and not the XC5.0 battery.
For the most up-to-date offers and prices, feel free to check the Milwaukee M18 REDLITHIUM XC4.0 Extended Capacity Battery Pack (48-11-1840) Amazon link (link opens in the new window).
Milwaukee M18 REDLITHIUM XC5.0 Extended Capacity Battery Pack (48-11-1850)
Milwaukee M18 REDLITHIUM XC5.0 Extended Capacity Battery Pack (48-11-1850) is probably the most popular Milwaukee M18 battery system battery, offering the best balance between the price, weight, stored energy, and the ability to provide high output currents.
The battery is intended for heavy-duty use and can be recharged faster than similar batteries while still keeping the battery temperature relatively low.
Also, the battery is able to operate at very low temperatures (0°F, -18°C), it features a fuel gauge, intelligent BMS, sturdy all-weather vibration-resistant construction, etc.
For all of these reasons, Milwaukee M18 XC5.0 (48-11-1850) battery is a very popular battery by both home users and professionals.
For the most up-to-date offers and prices, feel free to check the Milwaukee M18 REDLITHIUM XC5.0 Extended Capacity Battery Pack (48-11-1850) Amazon link (link opens in the new window).
Milwaukee M18 REDLITHIUM XC5.0 Resistant Battery Pack (48-11-1850R)
Milwaukee M18 REDLITHIUM XC5.0 Resistant Battery Pack (48-11-1850R) is very similar to the "ordinary" Milwaukee M18 RedLithium XC5.0 Extended Capacity Battery Pack (48-11-1850) (note missing "R" in the "48-11-1850").
The XC5.0 Resistant (48-11-1850R) battery model is built with a chemically resistant housing, providing increased protection against common oils, greases, solvents, and similar chemicals.
Other than that, these two batteries are practically the same.
Personally, Milwaukee M18 XC5.0 Resistant (48-11-1850R) battery is, for a reason, NOT a very common battery since "ordinary" Milwaukee M18 batteries are already built using very chemically resilient housings.
But, if You do need such a battery, consider this model - for more information, feel free to check the Milwaukee M18 REDLITHIUM XC5.0 Resistant Battery Pack (48-11-1850R) link (link opens in the new window).
Milwaukee M18 REDLITHIUM XC6.0 Battery Pack (48-11-1860)
Milwaukee M18 REDLITHIUM XC6.0 Battery Pack (48-11-1860) is able to store up to 108 Wh of energy, enabling the battery to power a broad range of Milwaukee M18 tools for a long period of time, especially low- and medium-power demanding tools.
Milwaukee M18 REDLITHIUM XC6.0 Battery Pack (48-11-1860) is a "typical" Milwaukee M18 battery, featuring robust construction, fuel gauge, intelligent BMS, all-weather construction, low-temperature operation, etc.
However, this is not a particularly battery for a few reasons:
- People looking for a balanced, mid-range Milwaukee M18 battery generally choose the M18 XC5.0 battery,
- People looking for a 6.0Ah M18 battery choose the High Output XC6.0 lithium battery, which runs cooler and is a better choice for heavy-duty use than the "ordinary" XC6.0 battery.
But, if this battery fits your needs, this is an excellent battery that comes at an acceptable price.
For the most up-to-date offers and prices, feel free to check the Milwaukee M18 REDLITHIUM XC6.0 Battery Pack (48-11-1860) Amazon link (link opens in the new window).
Milwaukee M18 REDLITHIUM HIGH OUTPUT XC6.0 Battery Pack (48-11-1865)
Milwaukee M18 REDLITHIUM HIGH OUTPUT XC6.0 Battery Pack (48-11-1865) is very similar to the previous XC6.0 (48-11-1850) model, but the High Output XC6.0 battery is intended for heavy-duty use and is designed to run cooler than other similar batteries, prolonging the battery lifetime.
With its 108Wh of stored energy, Milwaukee M18 REDLITHIUM HIGH OUTPUT XC6.0 Battery Pack (48-11-1865) is able to power even the most demanding M18 cordless tools while still not being too heavy for comfortable use.
Like all other Milwaukee M18 batteries, the High Output XC6.0 model also features intelligent BMS that protects the battery from unwanted events, fuel gauge, sturdy construction, low-temperature operation, etc.
Thanks to such features and performances, the High Output XC6.0 model is used in cordless tools that provide power levels equal to those of corded tools.
If the High Output XC6.0 model fits your needs, go for it. But, just for your information, many users that require high-capacity high-output M18 batteries choose High Output XC8.0 batteries which store even more (by 33% more) energy.
For the most up-to-date offers and prices, feel free to check the Milwaukee M18 REDLITHIUM HIGH OUTPUT XC6.0 Battery Pack (48-11-1865) Amazon link (link opens in the new window).
Milwaukee M18 REDLITHIUM HIGH OUTPUT XC8.0 Battery Pack (48-11-1880)
Milwaukee M18 REDLITHIUM HIGH OUTPUT XC8.0 Battery Pack (48-11-1880) is able to store 144Wh of energy and is able to provide high-discharge currents and to run cooler than similar batteries while doing so.
As such, Milwaukee M18 REDLITHIUM HIGH OUTPUT XC8.0 Battery Pack (48-11-1880) ensure performances that are very similar to the performances of corded tools.
The battery features physical dimensions of 5.46 x 3.3 x 3.22 inches (~13.9 x 8.4 x 8.2 cm), and it weighs ~2.3 pounds (~1.05 kg) which isn't much for such a battery but may be too much for tools that are used on awkward, narrow and/or overhead places - can lead to fatigue if used for a longer period of time in such conditions.
Of course, consider XC5.0 or High-Output XC6.0 M18 battery models for such tasks.
Although Milwaukee also offers HD9.0 (9.0Ah) and HD12 (12.0Ah) batteries, the High Output XC8.0 battery is the most popular "high-capacity" Milwaukee M18 lithium battery.
For the most up-to-date offers and prices, feel free to check the Milwaukee M18 REDLITHIUM HIGH OUTPUT XC8.0 Battery Pack (48-11-1880) Amazon link (link opens in the new window).
Milwaukee M18 REDLITHIUM HIGH DEMAND HD9.0 Battery Pack (48-11-1890)
Milwaukee M18 REDLITHIUM HIGH DEMAND HD9.0 Battery Pack (48-11-1890) is perhaps not as popular as the XC8.0 battery, but considering its size, weight, stored energy, price, etc., it is a rather popular battery used for heavy-duty applications.
Although lithium batteries are able to provide strong currents with ease and without significant loss of capacity due to the high-discharge currents, note that the High Demand HD9.0 M18 battery offers at least 2x more usable capacity than the very popular XC5.0 battery in heavy-duty applications - and this can be very important not only to professional users.
Designed for high-output currents, the High Demand HD9.0 M18 battery runs very cool considering its output power, prolonging the battery lifetime.
Also, the High Demand HD9.0 M18 battery offers vibration-resistant housing, fuel gauge, low-temperature operation, and all other features typical to a high-quality cordless tool battery.
So, You are interested in XC8.0 (8.0 Ah) battery, but now you are considering High Demand HD9.0 (9.0 Ah) battery?
Well, while the High Demand HD9.0 battery is an excellent high-capacity battery, Milwaukee also offers a High Demand HD12.0 (12.0 Ah) battery offering even better performances than XC8.0 and HD9.0 M18 batteries.
For the most up-to-date offers and prices, feel free to check the Milwaukee M18 REDLITHIUM HIGH DEMAND HD9.0 Battery Pack (48-11-1890) Amazon link (link opens in the new window).
Milwaukee M18 REDLITHIUM HIGH OUTPUT HD12.0 Battery Pack (48-11-1812)
Milwaukee M18 REDLITHIUM HIGH OUTPUT HD12.0 Battery Pack (48-11-1812) is a big and heavy battery, being able to store 216Wh(!) of energy to provide power levels equal to 15 Amps coded tools.
As such High Output HD12.0 M18 battery is used for heavy-duty applications that require plenty of power and energy from a relatively compact and relatively lightweight battery.
Milwaukee High Output HD12.0 M18 battery is designed to run cooler than similar batteries, which in combination with intelligent BMS prolongs the battery's lifetime.
Also, it features vibration and impact-resistant housing, fuel gauge, low-temperature operation, compatibility with 150+ Milwaukee M18 cordless tools, etc.
Obviously, this is not the battery for M18 screwdrivers or drills (XC3.0 or XC5.0 are a much better choice for such tools), but for applications where XC8.0 and even HD9.0 batteries are not large enough, go for High Output HD12.0 M18 battery.
For the most up-to-date offers and prices, feel free to check the Milwaukee M18 REDLITHIUM HIGH OUTPUT HD12.0 Battery Pack (48-11-1812) Amazon link (link opens in the new window).
How To Charge Milwaukee M18 Batteries
There is only one proper way of how to charge the Milwaukee M18 batteries - use Milwaukee M18 battery chargers and don't look any further.
Milwaukee M18 battery chargers differ in the number of slots, sizes, and shapes, but they are all designed to safely charge Milwaukee M18 batteries by starting to monitor the battery even before actual charging starts.
Some of the chargers are compatible with the Milwaukee M12 battery system, so be careful when trying to recharge more batteries at the same time - nothing bad will happen (the batteries will not overheat or catch fire), just the chargers may start to charge one battery type and only then another battery type.
Also, some Milwaukee battery chargers are designed to act even as a carrying cradle for the batteries - before storing the batteries for weeks/months on such chargers, read their Owner's Guides since some of them may even discharge the batteries stored on them over a longer period of time.
Personally, as soon as the battery is fully recharged, remove it from the charger.
For people wanting to start with Milwaukee M18 tools, note that Milwaukee also offers battery/battery chargers kits at very acceptable prices.
Milwaukee M18 Batteries Frequently Asked Questions (FAQ)
Here are some of the most common Frequently Asked Questions about Milwaukee M18 batteries and the Milwaukee batteries in general:
What is the strongest Milwaukee M18 battery?
The strongest Milwaukee M18 battery is the High Output HD12 M18 battery which features 3x capacity of the XC4.0 battery, but when used for powering high-demanding tools, it acts more like 3x XC5.0 batteries.
What is the longest-lasting Milwaukee M18 battery?
In terms of capacity, the longest-lasting is the Milwaukee M18 RedLithium High-Output HD12 battery. However, due to its size and weight, such a battery is not always the best choice, hence Milwaukee offers several batteries ranging from 1.5 to 12.0 Ah.
Is Milwaukee discontinuing M18?
No, Milwaukee is not discounting the M18 line of their tools, batteries, and chargers. Despite Milwaukee M28 operating at higher voltages, M18 is still one of their most popular systems.
So, why would they discontinue it...?
How many years do M18 batteries last?
When used, charged, and stored properly, Milwaukee M18 batteries can last 3-5 years.
What does the FUEL mean in Milwaukee tools?
All Milwaukee FUEL tools feature three Milwaukee technologies, including_
- the POWERSTATE Brushless Motor,
- the REDLITHIUM Battery Packs,
- the REDLINK PLUS Intelligence Hardware and Software.
As such, Milwaukee M18 FUEL tools offer performances up to or even more than 50% better than the "ordinary" Milwaukee M18 tools.
Of course, such tools also require High Output M18 Milwaukee batteries to keep the batteries as cool as possible and to recharge them as quickly as possible.
Can you use M18 Fuel batteries in M18?
There is no such thing as "M18 Fuel batteries" - Milwaukee offers various RedLithium batteries compatible with every Milwaukee M18 and Milwaukee M18 Fuel tool.
However, if You have a high-demanding, energy-hungry Milwaukee M18 Fuel tool, High Output RedLithium batteries are recommended.
How to charge the Milwaukee M18 battery without a charger?
While it is possible to recharge the Milwaukee M18 battery without the charger, it is not possible (or it is not easy) to reset the M18 battery without the charger.
If You have a Milwaukee M18 battery (or batteries), do yourself a favor and get the original Milwaukee M18 rapid lithium battery charger - they are not expensive, and they do their job well.
How to reset the Milwaukee M18 battery?
When the Milwaukee batteries are fully discharged, they must be recharged. Also, they must be reset, which is done by the Milwaukee M18 battery charger, which communicates with the battery.
In theory, it is possible to recharge the Milwaukee M18 battery using a battery charger set, for example, to 21V and 500 mA, but that would not reset the battery, and the battery will not work.
But, if the battery is not fully discharged (no need to reset it) and the battery is fully recharged using such a charger, it will work.
Note: don't do it. Get yourself a Milwaukee M18 rapid lithium battery charger, and don't risk overheating, fire, or even the explosion of your lithium battery pack! This is a serious warning and goes for every lithium battery, not only for Milwaukee M18 batteries.
Do Milwaukee batteries wear out?
Of course, they do. However, the number of charging and discharging cycles depends on the batteries' usage, charging conditions, storage conditions, and similar.
When used, charged, and stored properly, Milwaukee M18 batteries can withstand hundreds of charging/discharging cycles and 3-5 years of use.
How long does an M18 CP2.0 battery last?
When the new, fully charged Milwaukee M18 CP2.0 battery is discharged at a rate of 1A, it can provide such a current for ~2 hours, hence the capacity of 2Ah.
However, when the discharge current is increased, actual capacity decreases (current dependent). However, capacity loss in lithium batteries is much lower than the capacity loss in, for example, Nickel-Cadmium or Lead-Acid batteries.
What's the difference between Milwaukee XC and CP batteries?
Milwaukee offers several battery categories, including:
- CP batteries are compact batteries, generally used for tools that do not require extra strong currents. Also, these are the lightest battery packs.
- XC batteries are "Extended Capacity" batteries, offering a larger capacity than the CP batteries, and are intended for somewhat more demanding tools.
- HD batteries are "High Demand" and offer the largest capacity for the most demanding tools and applications.
Also, Milwaukee offers so-called "High Output" versions of their batteries that feature improved battery cells, allowing these heavy-duty batteries to run cooler.
Generally, CP batteries feature one row of batteries (mostly 18650), XC batteries feature two rows, and HD batteries feature three rows of batteries.
In order to provide even more power, some battery packs use 21700 batteries instead of 18650 batteries.
Are Milwaukee's high-output batteries worth it?
In short, yes, they are.
Can You charge an M28 battery with an M18 charger?
No, you cannot - Milwaukee M18 battery chargers are often compatible with M12 batteries, but for M28 batteries, use Milwaukee M28 battery chargers:
Note: It is possible that Milwaukee will offer one day an M12/M18/M28 battery charger, but until then, use a dedicated M28 battery charger.
Few Final Words
Milwaukee M18 tools are very popular for both professional and DIY use, offering excellent tools, batteries, and chargers at acceptable prices.
While most of these devices are very easy to use and maintain, whenever a new device arrives, whether it is a tool, battery, or battery charger, read the Owner's Guide - better safe than sorry.
Milwaukee M18 batteries differ greatly in their size, weight, and capacity, so be sure to choose according to your own needs and requirements.
And whatever You do, stay safe!
