Battery packs for power tools

The best part about cordless drills is well, they are cordless! The worst part of them is that they have limited battery life.

There are different types of battery packs for different tools. There are different voltages and different capacities (mAh or Ah). The ampere-hours (labeled Ah) denote the maximum amount of charge the battery can store at a given time. This, in turn, determines how long you can operate the drill or other power tool with the particular battery pack.

Rechargeable batteries for power tools generally contain cells with a voltage of 1.2V, 1.5V or 3.6V. Manufacturers utilize these cells to produce batteries that can have a voltage of anywhere between 3.6V and 48V. The main difference between 12v, 18v, and 20v tools is their power; the higher the voltage of the tool typically the more powerful it can be. High voltage in a power tool usually translates to higher torque. Usually a 12v tool has less power compared to the same type 18 and 20-volt tools. Theoretically, the higher voltage doesn’t mean more power in and of itself, and there are other features besides voltage that affect the power available from tool. So, is higher voltage better for cordless tools? It depends on the task you’re using the tool for. If you want something with more torque for a tougher job, then a higher voltage is a better solution. However, lower some voltage offers superb energy savings compared to some more powerful higher voltage tools. Power tools that come with a high voltage typically cost a lot more money than tools with a low voltage and are usually heavier.

Batteries that have a voltage between 3.6V and 12V are generally designed in light duty tools, such as cordless screwdrivers and small cordless drill drivers. Batteries that have a voltage between 14.4V and 36V are manufactured for use on heavier duty tools such as cordless hammer drill drivers, cordless angle grinders, and cordless circular saws. The most common voltage nowadays used amongst manufacturers (due to its weight, cost, and potential power output) is 18V or 20V.

But there are various other factors that determine the overall functionality of a rechargeable battery. The type of materials used to make the battery and the underlying principle of how it powers up the tool play also play a major role. The most common battery chemistries are NiCd, NiMH, and Lithium. NiCd is the oldest battery type of those, and it no longer used within EU because there is a law banning the toxic substance cadmium from portable batteries. Newer NiMH batteries can have two to three times the capacity of NiCd batteries of the same size, with significantly higher energy density.

Most power tools manufacturers boast of using a Lithium (Li) ion battery to power their cordless drills. Lithium (Li) provides the highest energy storage capacity and the batteries will hold the charge for a long time when not used. Lithium batteries can be extremely lightweight and can have compact size. They hold a high amount of energy. There disadvantages of the Lithium batteries are that they can be damaged by heat and impact and that they are relatively more expensive than other batteries.

So, are cordless drill batteries and chargers interchangeable? The answer depends on the types of batteries, the drill model and manufacturer, and the overall power specifications of the two items being swapped. Typically the cordless drill batteries from two different brands are not normally interchangeable. But batteries of a particular brand can often be used interchangeably on some different drills or other tools of the same brand. Trying to interchange cordless drill batteries or using a charger from a different brand can easily damage these power tools, and they are typically made mechanically incompatible so user can’t fit in “wrong type” battery.

The non-compatibility of a battery pack with the drill of an alternative brand is what enables manufacturers to stay profitable in the long run! Companies intentionally design their batteries in a way that they cannot work with drills produced by a competitor brand. So if the battery pack goes bad and they want to continue to use their tool, they need to buy a new expensive battery pack the manufacturer sell. Also the users that have already many batteries and tools from one brand, want to buy their new tools from the same brand so that they can use their existing batteries with them. This ensures that customers will keep coming back as their drill batteries reach the end of their lifespan and they have to buy new ones, or they need an extra set to power their drills for extensive projects. Moreover, the lack of battery compatibility across different brands also helps companies ward off warranty claims (you are likely to notice something along the lines that the use of third party products will void the warranty on the said tool). Most rechargeable batteries for cordless drills have an average lifespan of three years to five years.

When the cordless power tools have been brand specific earlier, now it seems that there is some standardization coming to power tools. Power or All Alliance and Cordless Alliance System have developed standards for cross-manufacturer cordless freedom where same battery works with many brands of tools. They promise that now you can combine machines, battery packs and chargers of different manufacturer with each other without any problems.

Cordless Alliance System (CAS) is a cross-manufacturer battery pack system of leading power tool brands. It promises 100% compatibility for over 280 machines in the 18 V class! The focus is on 18V the most important application range for professional users. This battery alliance originated from Metabo batteries. The brands in this alliance include Metabo, Mafell, Rothenberger, Callomix, Eibenstock, Eisenlätter, Haaga, Starmix, Steinel, Rokamat, Birchmeier, Edding, Fischer, Prebena, Cembre, Pressfit, Jöst, Trumpf, Gesipa, Montipower, Scangrip, Baier, ITH, Cemo and Spewe.

Power or All Alliance says to be one of the largest cross-brand 18V battery systems. It promises to provide THE battery for your home and garden. Their vision is to provide our users with ONE battery that can be used for all use cases in and around the home. One and the same 18V battery within the POWER FOR ALL ALLIANCE is 100% compatible with all 18V appliances of the brands Bosch Home & Garden, GARDENA, Bosch Home Appliances, GLORIA House and Garden, Wagner, Flymo, Steinel and Rapid.

There is also 20V MAX POWERCONNECT battery system used by several manufacturers. For example Black+Decker, Dewalt, Bosch and Nilfisk support this battery system. Power a range of BLACK+DECKER power tools, vacuums, and lawn + garden equipment using the same interchangeable batteries and chargers in the 20V MAX* POWERCONNECT™ Battery System.

LIDL sells a quite large selection of tools that use Parkside X 20V team battery system. I have reviewed this system at my Parkside X20V Team battery packs from LIDL posting. This is not an official multi manufacturer standard, but according to discussion the same type of batteries are used also by some other brands like aeg. Parkside Performance series is a newer series with better motor and longer-lasting battery than with Parkside X20V Team series but is not compatible with it.

USB Type-C was intended to be the universal connector for almost all data and charging needs. It’s slowly replacing countless types of proprietary chargers is making its way to power tools. Two companies have announced batteries and tools with the connector: Ryobi has announced a new “USB Lithium” series of tools (based on a new 4V Max/3.6V Li-ion battery) and DeWalt is also jumping onto the USB Type-C train.

Ryobi has announced a new “USB Lithium” series of tools, all using the same 2.0Ah removable battery with a USB Type-C port for charging. That means you don’t need to have a custom dock to charge up the batteries.

DeWalt and Ryobi are both producing adapters that allow their existing larger batteries to be charged with USB Type-C, along with the required wall adapters.



  1. Tomi Engdahl says:

    Are Cheap Power Tool Batteries better than DeWalt 20V OEM Lithiums? Let’s find out!

    $59 DCB-205 20V Dewalt OEM Lithium Ion, $26 Vanon, and $27 Waitley 20V Lithium Ion batteries compared for performance. Batteries tested for high and moderate drain performance and cold temperature performance. Battery pack dismantled and individual cells tested for milliamp hour (mAh) capacity and internal resistance. Advertised watt hours calculated and compared to calculated watt hour performance.

    Which 20V Replacement DeWalt Battery is the BEST? | Knockoffs VS DeWalt Comparison

    Looking for some replacement batteries for your 20V DeWalt tools but you don’t want to shell out an arm and a leg? Well then this video is for you…

  2. Tomi Engdahl says:

    Use any brand battery in any power tool 18v-20v DEWALT MILWAUKEE MAKITA PORTER CABLE BOSCH adapters

    Dewalt battery in a Makita, Makita in a Milwaukee, Milwaukee in a Dewalt, Dewalt in a Ryobi, Porter Cable in a Makita………………… The possibilities are endless with battery adapters.

  3. Tomi Engdahl says:

    New power tool battery technology
    One of the most recent developments to the market is DeWALT’s new FLEXVOLT battery. The batteries are fully compatible with existing DeWALT 18V XR tools and when fitted to the new DeWALT XR FLEXVOLT tools the voltage then surges to an unparalleled 54V. FLEXVOLT is a world first with this new 18/54V battery platform and the aim as DeWALT state is to give you: “the power of corded, freedom of cordless.”

  4. Tomi Engdahl says:

    #416 Creative uses of Power Tool Batteries for Mobile Projects

    Most of us own at least one battery-operated power tool, including a charger. What if we could use their batteries also for our electronics projects? Let’s have a closer look!

    Viewer comments:

    I believe Ryobi brand 18V batteries have undervoltage projection built into the battery. It’s pretty uncommon in other brands though.

    Thank you for the info. Others mentioned that Makita batteries are also protected. Mine are not, but Lidl replaced mine ;-)

    Rob is right here. Ryobi batteries are expensive because they got their protection built-in, that’s why the tools are cheaper, too.

    They are protected and even showing the battery level,

    Milwaukee has built in protection as well, they even have a temp sensor, and without it it’s charger will not charge them.. Ask how I know

    For Makita (at least LXT) the protection comes from the tool . There is also a board inside but it does not disconnect – or + .. those go directly to accus

    Ryobi indeed does, and it sucks. if you pull the juice really quick it will not clamp fast enough and they will cut out and won’t take a change. you have to dissemble the battery and bypass the controller and spoon feed it.

    Makita batteries (at least the ones I[ve had apart) do not have undervoltage protection – this would require a 100A capable switchiung device in the battery – there is no point in them including this as the power tool itself has switching for speed control.

    From what I’ve heard (never owned or taken apart a lithium makita battery), some do and some don’t depending on age and capacity.

    Dad uses the AEG (rigid in America) ecosystem primarily because at least as far as we know, they always have had some for of protection in the battery. From attemping to fix a water damaged one and reading online, the batteries don’t have cell balancing, but do have individual cell monitoring and over temperature cutoff. Power switching is two large mosfets in reverse in series so the battery can also be isolated if overcharged and when flat. There is definitely no protection in some of the tools we have – one rattlegun that blew up consisted of a 555 timer as the speed control and a small microcontroller that did nothing else except turn the led light on and fade it out. The battery protection circuit definitely gets a workout and automatically resets as devices like angle grinders and chainsaws will routinely overheat and rapidly discharge batteries.

    The overall main components and approach seems to be fairly similar to a moderately recent big clive video of a teardown of a no name battery.

    I believe einhell has some built in protection and doesn’t break the bank either

    @Andreas Spiess are you aware of any over discharge protection modules that could be used in home made ‘accessories’? The normal 5S BMS modules all seem to require direct connections to the individual cells of the pack.

    You can buy adjustable Relay and/or Mosfet based under-voltage modules from the usual online places. I have one on my desk right now – model XY-CD60 – however there are literally hundreds of different options

    @Dan Nuțu – any device or circuit that monitors a battery will drain the battery, just like the inbuilt BMS of a battery drains the battery. However the drain of a decent under-voltage cut-off circuit is absolutely TINY compared to the capacity if the battery itself.
    Any such drain is irrelevant if you charge the battery after using it. However if you leave the battery fot 12 months after you have fully drained ot to the cutoff voltage, then it might cause an issue.
    The Ryobi tool batteries are notorious for that because the BMS runs off the first cell only. So if you store a Ryobi battery in a discharged state for a long period, the first cell(s) in the pack gets destroyed, which makes the whole pack unusable.

  5. Tomi Engdahl says:

    Ruotsalainen Husqvarna liittyy tiukemmin Boschin alulle panemaan Power for All -akkuallianssiin, jossa yksi sama 18 voltin akkupaketti käy useiden eri valmistajien pienlaitteisiin. Allianssissa ovat mukana Boschin ja Husqvarnan lisäksi Gardena, Bosch, Flymo, Gloria, Steinel, Rapid, Wagner, Perfect Pro ja Kûbler Workwear.

    Akkukäyttöiset pienkoneet ovat yleistyneet nopeasti, joten akkuja alkaa olla jo varsin montaa sorttia. Yleensä ne eivät ole yhteensopivia muiden valmistajien kanssa. Kaksi vuotta sitten Bosch lähti hakemaan laajempaa yhteensopivuutta 18 voltin Power for All -yhteenliittymällä. Ja sai samalla lisää bisnestä akkutuotantoonsa, koska allianssiyritysten kaikki akut tulevat Boschilta.

  6. Tomi Engdahl says:

    Battery Low-Voltage Cutoff
    Don’t kill your rechargeables.

    I’m knocking together a gadget to run 12V devices off of 18V Ryobi One+ battery packs (of which I have a few). I found a sufficiently beefy buck converter a while back that knocks 18V (nominal) down to 12.6V, but there’s nothing in it to keep the battery from being discharged too much. This circuit will cut off its output at around 14.28V…2.86V per cell for Li-ion, 952 mV for NiCd (since I still have some of those).

  7. Tomi Engdahl says:

    Ryobi Battery Hack Keeps CPAP Running Quietly

    When it comes to cordless power tools, color is an important brand selection criterion. There’s Milwaukee red, for the rich people, the black and yellow of DeWalt, and Makita has a sort of teal thing going on. But when you see that painful shade of fluorescent green, you know you’ve got one of the wide range of bargain tools and accessories that only Ryobi can offer.

    Like many of us, Redditor [Grunthos503] had a few junked Ryobi tools lying about, and managed to cobble together this battery-powered inverter for light-duty applications. The build started with a broken Ryobi charger, whose main feature was a fairly large case once relieved of its defunct guts, plus an existing socket for 18-volt battery packs. Added to that was a small Ryobi inverter, which normally plugs into the Ryobi battery pack and converts the 18 VDC to 120 VAC. Sadly, though, the inverter fan is loud

  8. Tomi Engdahl says:

    Saksalainen Bosch vahvistaa pienkoneidensa akkuallianssia nostamalla osakeomistuksensa ruotsalaisen Husqvarnasta 12 prosenttiin. Husqvarna-konserniin sisältyy myös tytäryhtiö Gardena ja sen Flymo-brändi, jotka ovat mukana Boschin Power for All -allianssissa.

  9. Tomi Engdahl says:

    ALDI/Ferrex cordless drill PCB

    And finally the 20V tool PCB for the 20/40V battery pack system. This shares the same complex power management system as the others for ultra low standby current.

    It’s quite perplexing. I think two of the inputs are analogue for voltage monitoring.

    An unexpected feature of this module is that it doesn’t control the tool directly, but just sits between it and the battery. When the tool is used this module detects the load, wakes up and switches on the MOSFETs to allow the tool to be powered fully. The bulk of the circuitry is to allow the module to sleep when not needed.


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