You grab a battery off the shelf, slide it toward your drill, and… it doesn’t fit. Or it fits but the tool won’t power on. If that’s happened to you, you’re in good company — cordless tool batteries are one of the most confusing purchases in the entire home improvement aisle. Brands use similar-sounding names like “20V MAX” and “18V,” similar shapes, and sometimes even similar colors, but none of that means the batteries are interchangeable. In fact, almost none of them are.
This guide sorts out exactly which batteries work with which drills, brand by brand. We’ll walk through the major platforms — DeWalt, Milwaukee, Makita, Ryobi, Bosch, Craftsman, Black+Decker, Kobalt, Ridgid, Metabo HPT, and Skil — explain why voltage labels are misleading, show you how to check compatibility before you buy, and flag the real risks of off-brand adapters. By the end, you’ll be able to look at any battery and know immediately whether it belongs in your toolbox.
Quick Facts
| Question | Answer |
|---|---|
| Do batteries work across different brands? | No — no major brand shares a battery platform with a competitor |
| How many major cordless platforms exist in the US market? | About a dozen: DeWalt, Milwaukee, Makita, Ryobi, Bosch, Craftsman, Black+Decker, Kobalt, Ridgid, Metabo HPT, Skil, Ego |
| Most common voltage labels | 18V nominal, 20V MAX, 24V MAX, 40V MAX |
| Typical amp-hour (Ah) range | 1.5Ah to 9.0Ah |
| Approximate battery weight | Roughly 0.7–2.6 lb depending on capacity (varies by brand and cell design) |
| Recommended charging/storage temperature | Follow your charger’s stated rating — DeWalt and Milwaukee manuals specify 40°F–105°F (4.5°C–40.5°C), and Makita chargers say do not charge below 50°F (10°C) |
| Typical battery lifespan | Several years of regular use; capacity gradually declines with charge cycles |
| Commonly referenced safety standard | UL 2054 (lithium-ion battery pack safety) |
Here’s the direct answer up front: cordless drill batteries are locked to a single brand’s specific tool platform, not to a voltage number. A DeWalt 20V MAX battery will never fit a Milwaukee M18 drill, even though both are roughly 18 volts nominal. Each brand designs its own battery terminal layout, communication chip, and physical rail system, so compatibility comes down to brand and product line — not the number printed on the label.
Why “20V” and “18V” Batteries Aren’t Actually Different
Here’s the detail that trips up most shoppers: voltage labeling is a marketing choice, not proof of a physical or electrical match. A lithium-ion cell has a nominal voltage of about 3.6V–3.7V. Most cordless drill packs wire five cells in series, which works out to roughly 18V nominal and about 20V at peak charge with no load. DeWalt, Craftsman, and Black+Decker market this as “20V MAX” because they’re advertising peak voltage. Milwaukee, Makita, Bosch, and Metabo HPT call the same underlying chemistry “18V” because they’re advertising nominal voltage. It’s the same battery science with a different number on the sticker — which means two tools labeled differently can be closer in real output than two tools labeled the same.
Kobalt’s higher-end line steps up to 24V MAX using six cells, and several outdoor power platforms (Ego, some Ryobi lawn tools) run 40V–56V packs built from stacked cell groups. None of these cross over with standard drill batteries, and the voltage number still won’t tell you whether a battery physically fits.
Cordless Drill Battery Compatibility Chart by Brand
This is the core reference — bookmark it. Each row shows the platform name, the voltage label used in marketing, and whether batteries carry over to other tools within that same brand.
| Brand | Platform | Voltage Label | Works With Other Brands? | Compatible With Own Older Tools? |
|---|---|---|---|---|
| DeWalt | 20V MAX / FlexVolt | 20V MAX (18V nominal); FlexVolt 20V/60V | No | Yes — 20V MAX batteries fit nearly all DeWalt 20V MAX tools; FlexVolt batteries also run in standard 20V MAX tools |
| Milwaukee | M12 / M18 / MX Fuel | M12 (12V), M18 (18V), MX Fuel (72V) | No | Yes within each line — M18 batteries fit all M18 tools; M12 is a separate, smaller platform |
| Makita | 18V LXT / 40V XGT | 18V (LXT), 40V MAX (XGT) | No | Yes within LXT; XGT is a newer, separate 40V line |
| Ryobi | ONE+ 18V / ONE+ HP | 18V | No | Yes — ONE+ has maintained battery compatibility across most of the platform’s history, including newer ONE+ HP tools |
| Bosch | 18V / 12V Max | 18V, 12V | No | Yes within each voltage line |
| Craftsman | V20 | 20V MAX | No — the V20 rail is not designed to accept DeWalt batteries, despite shared ownership | Yes within the V20 line |
| Black+Decker | 20V MAX | 20V MAX | No — not compatible with DeWalt or Craftsman despite the shared parent company | Yes within B+D’s 20V MAX line |
| Kobalt | 24V MAX / KXD | 24V MAX | No | Yes within the 24V MAX line |
| Ridgid | 18V / OCTANE | 18V | No | Yes — OCTANE and standard 18V packs cross-compatible with each other |
| Metabo HPT (formerly Hitachi) | 18V / MultiVolt | 18V, MultiVolt 18V/36V | No | Yes within the 18V line; MultiVolt batteries are designed to also run in standard 18V tools |
| Skil | PWRCore 12/20 | 12V, 20V MAX | No | Yes within each voltage line |
Notice the pattern: Stanley Black & Decker owns DeWalt, Craftsman, and Black+Decker, yet all three use physically different battery rails. Sharing a corporate parent doesn’t mean sharing hardware.
Battery Sizes and What the Numbers on the Label Mean
Once brand and platform match, the next thing to check is amp-hours (Ah), which tells you runtime — not voltage, and not power. A higher Ah pack runs longer between charges and weighs more, but it won’t make the tool spin faster or hit harder.
| Amp-Hour Rating | Relative Weight | Approx. Charge Time (standard charger) | Best For |
|---|---|---|---|
| 1.5Ah | Lightest | ~30–45 minutes | Light drilling, driving screws, compact drills |
| 2.0Ah | Light | ~40–60 minutes | General household use |
| 4.0Ah | Medium | ~60–90 minutes | Extended projects, small job sites |
| 5.0Ah | Medium-heavy | ~75–100 minutes | Heavier drilling, mixing paddles |
| 6.0Ah | Heavy | ~90–120 minutes | All-day job site use |
| 9.0Ah | Heaviest | ~120–150 minutes | High-drain tools like hammer drills and saws |
Exact weights and charge times vary by brand and charger, so treat the numbers above as ballpark figures rather than guarantees — check your battery and charger’s spec sheet for exact numbers. Fast or rapid chargers can cut charge times noticeably, but they also draw more current and generate more heat in the pack, so stick to the charger your manufacturer recommends for that battery.
Can You Use an Adapter to Cross Brands?
Third-party adapters exist that claim to let a Milwaukee battery power a DeWalt tool, or a Makita battery run in a Ryobi drill. No major tool manufacturer makes or endorses these adapters, and they come with real downsides:
- They bypass the battery’s built-in communication circuit, which normally regulates current, temperature, and cell balance for that specific tool’s power draw.
- Mismatched voltage or current delivery can overheat the pack or stress the tool’s motor controller, which is a big part of why manufacturers don’t support cross-brand adapters.
- Using an adapter will very likely void the warranty on both the tool and the battery, since neither manufacturer has approved the modification.
If you’re switching platforms and have old batteries left over, it’s usually cheaper and simpler in the long run to sell them and buy into the new platform’s official packs than to rely on an adapter.
Mixing Batteries Within the Same Brand — Old vs. New Generations
Even within one brand, generations of tools can behave differently:
- DeWalt: Older 20V MAX tools generally work fine with newer 20V MAX batteries, including FlexVolt packs running in 20V mode. However, some compact 12V MAX tools use a completely separate, smaller battery — check the tool’s label, not just the brand.
- Milwaukee: M12 and M18 are two entirely different battery sizes and are never interchangeable, despite both saying “Milwaukee” on the case.
- Makita: Older 18V LXT batteries (without the fuel gauge display) still fit current LXT tools, but old 12V or 9.6V NiCd Makita batteries from decades past do not fit modern 18V tools.
- Ryobi: ONE+ 18V has stayed remarkably consistent for most of its history — a real advantage if you’re building a long-term tool collection, since a battery bought today will very likely still work with an older ONE+ drill.
How to Check Compatibility Before You Buy
- Match the brand name printed on both the tool and the battery — not just the color scheme, since some brands use similar color palettes.
- Match the platform name (for example, “M18,” “ONE+,” “20V MAX,” “LXT”) printed near the voltage on the battery label.
- Check the battery’s foot/rail shape against your tool’s slot — manufacturers occasionally tweak the physical mounting between sub-generations, even under the same platform name.
- If ordering online, search your drill’s exact model number on the manufacturer’s official site and check the “compatible batteries” or “accessories” list before buying a third-party or off-brand pack.
- Skip unbranded “universal” batteries sold on marketplace sites unless they explicitly list your exact tool model and carry UL 2054 certification — the safety standard most commonly referenced for lithium-ion battery packs.
Battery Care, Storage, and Safety
Because lithium-ion battery packs store a lot of energy in a small space, a few basic habits go a long way toward protecting your tools and your home:
- Charge and store batteries in a moderate temperature range — follow the range printed in your charger’s manual. DeWalt and Milwaukee specify roughly 40°F–105°F (4.5°C–40.5°C), and Makita chargers warn against charging below 50°F (10°C). Charging outside the stated range can trigger a charger’s safety cutoff or reduce capacity over time.
- Never charge a battery that’s visibly swollen, cracked, or leaking — stop use immediately and follow the manufacturer’s disposal or recycling instructions.
- Let a battery cool for a few minutes after heavy use before putting it on the charger; charging a hot pack right away shortens its lifespan.
- If you charge batteries near a sink, in a garage with a floor drain, or anywhere damp, plug the charger into a GFCI-protected outlet.
- Store batteries away from loose metal objects like screws or nails that could bridge the terminals and cause a short.
- Like all lithium-ion batteries, drill packs gradually lose capacity with age and repeated charge cycles — that’s normal wear, not a defect, and it’s the main reason performance drops off after a few years of regular use.
FAQ
Can I use a DeWalt battery in a Craftsman drill?
No. Even though Stanley Black & Decker owns both DeWalt and Craftsman, the 20V MAX battery rails and communication contacts are physically and electronically different between the two lines. They won’t click into place on each other’s tools.
Is 20V MAX the same as 18V?
Functionally, yes, in most cases. “20V MAX” refers to the peak voltage of a fully charged 5-cell lithium-ion pack, while “18V” refers to the nominal (average, resting) voltage of that same type of pack. The underlying chemistry and real-world output are typically very close between brands using either label — it’s a marketing distinction more than a technical one.
Do all Ryobi ONE+ batteries fit all Ryobi ONE+ tools?
Almost all of them, yes. Ryobi has kept its ONE+ 18V platform consistent for most of its long history, so a battery bought today will generally fit a drill, saw, or trimmer from years back, and vice versa — one of the platform’s biggest selling points.
Are third-party “universal” batteries safe to use?
Only if they explicitly list your exact tool model as compatible and carry UL 2054 certification. Generic adapters that force a battery from one brand into another brand’s tool bypass built-in safety communication and aren’t recommended by any manufacturer.
Why does my old battery charge but die quickly?
Lithium-ion battery packs naturally lose capacity over time as they go through charge cycles. If a battery that’s a few years old drains noticeably faster than it used to, it’s likely reached the end of its useful life rather than being defective.
Can I charge a cordless drill battery in cold weather?
Charge only within the range your charger’s manual states — DeWalt and Milwaukee specify about 40°F to 105°F (4.5°C to 40.5°C), and Makita chargers say not below 50°F (10°C). Charging a cold pack can damage the cells or cause the charger to refuse to start — bring the battery indoors to reach room temperature before charging.
Does a higher amp-hour battery make my drill more powerful?
No. Amp-hours (Ah) determine runtime — how long the battery lasts before needing a recharge — not torque or speed. Power output comes from the tool’s motor and the battery’s voltage platform, not the Ah rating.
Will FlexVolt or MultiVolt batteries work in my standard 18V/20V tools?
In most cases, yes. DeWalt FlexVolt batteries automatically switch to 20V mode when used in standard 20V MAX tools, and Metabo HPT’s MultiVolt batteries are designed to also run in standard 18V tools. Both are built to stay backward-compatible within their own brand’s platform, so check your specific tool and battery model to confirm.
Reviewed and edited by Jason Paik. Spotted an error? Tell us — we verify and correct. See how we create content.