A dead battery is the most common reason a cordless mower gets parked mid-season. Lithium-ion cells lose capacity over years, especially when they’re stored through winter in a cold garage, so most homeowners eventually need a replacement or a spare. The eight packs below cover the full range of Black + Decker platforms: 12V, 18V, 20V, and 40V MAX. Matching the right voltage to your specific tool family matters more than chasing the highest amp-hours number, so I’ve flagged the platform each pack serves.
A Quick View Of The Lineup
BLACK+DECKER 20V MAX POWERCONNECT 1.5Ah Battery + Charger
BLACK+DECKER 20V MAX 4Ah Lithium Ion Battery (LB2X4020-OPE)
18V 6.0Ah Replacement Battery for Black and Decker 18V Tools
3.6Ah 40V MAX Replacement Battery for Black and Decker 40V
3.6Ah 40V Replacement Battery for Black and Decker 40V with Charger
3.6Ah 40V MAX Replacement Battery (2-Pack) for Black and Decker
4500mAh Ni-MH 12V HPB12 Battery for Black and Decker A1712 FS120B
2-Pack 20V 3.5Ah Replacement Battery for Black and Decker LBXR20
A Breakdown Of The Leading Choices
This factory-original 1.5Ah pack ships with its own charger, so anyone buying a tool-only mower can get running the same afternoon. The 20V MAX* POWERCONNECT platform is the company’s broadest cordless ecosystem, meaning this single battery fits dozens of trimmers, blowers, and hedge tools beyond the mower itself. Runtime sits on the lighter end of the lineup, but the smaller cell keeps the pack itself light enough that swapping it into handheld tools doesn’t feel like a chore.
For someone with a small urban yard where the mower is out for 20 minutes and back in the garage, the tradeoff feels reasonable. Compared to the BLACK+DECKER 20V MAX 4Ah (Item 2), runtime is roughly a third of what you’d get there, but the price entry is friendlier and the included charger removes a separate purchase.
Advantages To Know
- Genuine OEM pack, so firmware and fit match every 20V MAX tool without guesswork.
- 1.5Ah capacity keeps the cell light, which matters on handheld tools like trimmers and leaf blowers.
- Charger is included in the box, so there’s no second purchase to budget for.
- POWERCONNECT compatibility means one pack moves between mowers, drills, and outdoor tools in the same family.
Things To Consider
- 1.5Ah is on the lean side for any lawn over roughly a quarter acre, so it may need a recharge mid-mow.
Made For
First-time cordless mower shoppers on a small lot who want the simplest plug-and-play setup without buying a separate charger.
Look Elsewhere When
The BLACK+DECKER 20V MAX 4Ah (Item 2) is a smarter match for anyone mowing a half-acre or larger where a lean pack would die before the job is done.
This is the top-capacity OEM battery in the 20V MAX family, and it shows in real mowing sessions where the smaller 1.5Ah pack would need a swap. A 4Ah cell roughly triples the runtime of the entry option above, which translates to finishing a medium yard in one charge rather than two. The LB2X4020-OPE ships as a battery-only unit, so anyone replacing a dead pack on an existing charger can skip the redundant accessory.
For homeowners who already own the 20V ecosystem and just need more mowing time, the upgrade is straightforward. Compared to the Item 1 starter kit, this is the same voltage family with more muscle, while the 40V packs lower in this list serve a completely different mower line.
Practical Advantages
- 4Ah is the highest factory-rated capacity in the 20V MAX platform, extending per-charge runtime substantially.
- Genuine OEM construction means the cell housing, contacts, and firmware all match the tool it snaps into.
- Larger capacity reduces charge cycles over a season, which can extend overall cell life.
Worth Noting
- Charger not included, so owners of the original LBXR20CK kit won’t need it but first-time shoppers will.
- The added capacity also adds noticeable weight over the 1.5Ah pack, which can fatigue the wrist during extended trimmer use.
Feature Snapshot
Best Suited To
Owners of medium-sized lawns who already use 20V MAX tools and want the longest factory runtime without jumping to the 40V platform.
Reach For A Different Pick When
The NEPOWILL 2-Pack 20V 3.5Ah (Item 8) makes more sense for someone building a fleet of spare packs rather than upgrading to one large cell.
The 18V Black + Decker line predates the current 20V MAX platform, and getting factory replacements has gotten harder over time. This third-party pack is rated at 6.0Ah (6000mAh) and covers a long list of legacy model numbers like HPB18, 244760-00, A1718, and the Firestorm FS18 family. For someone with an old cordless mower still running but with a dying battery, this pack keeps that tool alive instead of forcing a whole new mower purchase.
The capacity is generous for the platform, and the broad model-number coverage means it should fit anything in the older 18V ecosystem. Compatibility check is critical here: anyone considering this needs to verify their specific model number is on the supported list, since 18V and 20V packs are not interchangeable.
Benefits That Matter
- 6.0Ah capacity gives legacy 18V mowers a runtime boost compared to original factory cells.
- Broad compatibility list covers HPB18, A1718, Firestorm FS18, and related models.
- Lithium-ion chemistry means lighter weight than the original Ni-Cd packs many of these tools shipped with.
Points To Note
- Third-party brand (Qwenoer), so long-term cell reliability is less predictable than OEM alternatives.
- Model-number matching matters: 18V packs won’t fit 20V MAX tools, and confusing the two wastes a purchase.
Quick Facts
Whose Shelf It Belongs On
Homeowners still using older 18V Black + Decker or Firestorm cordless mowers who don’t want to replace the whole tool just to get back to cutting.
Swap It Out When
The Hanaix 12V HPB12 (Item 7) is the right replacement for tools on the even older 12V Ni-MH platform rather than the 18V line.
The 40V platform handles bigger mowers and tougher outdoor tools like string trimmers, chainsaws, and leaf blowers, where 20V packs start to feel undernourished. This 3.6Ah replacement from Forrat (3600mAh, 144Wh) targets the common 40V models like LBX2540, LBX2040, and LBXR36. For anyone whose original 40V pack is showing its age after several seasons, this gives a fresh cell without retiring the mower itself.
The watt-hour rating (144Wh) translates into meaningful cutting time on a typical 40V mower deck. Compared to the 20V picks earlier in this list, the same nominal runtime from a 40V pack arrives with more torque headroom for thicker grass.
What It Does Well
- 40V output supports full-size mowers and high-demand tools, not just handheld trimmers.
- 144Wh capacity gives real mowing time on a standard residential lot.
- Listed compatibility with the LCS36 and LCS40 chargers means no charger hunt.
Honest Caveats
- Forrat is a third-party brand, so the long-term capacity retention over years of use is less predictable than OEM.
- 40V packs weigh more than 20V equivalents, and the heavier cell can fatigue the arm during extended trimmer work.
The Right Fit
Shoppers with a 40V mower or outdoor tool whose original battery has lost capacity and who want a single replacement at a reasonable outlay.
Where Another Pick Suits Better
The Forrat 3.6Ah 40V with Charger (Item 5) is the better choice for first-time 40V shoppers who don’t yet own a compatible charger.
This is the same Forrat 3.6Ah 40V cell as Item 4, but bundled with a charger so a first-time 40V shopper can get everything in one box. For anyone buying a tool-only 40V mower, this removes the second purchase and gets the system running the same day. The charger is rated for the LCS36 and LCS40 platforms, which covers the common 40V tool families.
The single-pack format means anyone already owning a working 40V battery should pick the standalone version (Item 4) to avoid a duplicate charger. This bundle specifically helps new adopters.
Well-Handled Touches
- Charger included, removing the need to source the LCS36 or LCS40 separately.
- Same 144Wh capacity as the standalone version, so runtime isn’t sacrificed for the bundle.
- Single-pack pricing is reasonable for an entry into the 40V platform.
Trade Offs
- Owners who already own a charger shouldn’t pay for this bundle when Item 4 is enough.
- Only one battery ships in the box, so extended mowing still requires a stop to recharge.
Right Fit For
Homeowners stepping into the 40V MAX platform for the first time who don’t yet own the matching charger.
Skip It When
The Forrat 40V 2-Pack (Item 6) is the smarter call for anyone who already has a charger and wants to hot-swap packs during longer mowing sessions.
Two 3.6Ah 40V packs in one box solve the most common frustration with cordless mowing: running out of battery mid-lot. While one pack drives the mower, the other charges on the dock, and the swap happens in seconds. For anyone with a larger yard or a tendency to put off mowing until the grass gets tall, that hot-swap workflow is the difference between finishing Saturday and finishing Sunday.
The 2-pack format assumes you already own a working 40V charger. If you don’t, the bundle version (Item 5) covers both needs in one purchase.
Strong Points
- Two-pack design enables continuous mowing by rotating a fresh pack onto the mower.
- 144Wh per cell matches the runtime of the standalone version, so no capacity compromise per pack.
- Lithium-ion cells retain usable capacity well across a full mowing season.
Points To Keep In Mind
- Charger not included, so this only makes sense for households that already own the LCS36 or LCS40.
- Storage requires space for two packs plus the charger, which matters in tight garage setups.
Feature Card
Who It Suits Best
Owners with a larger yard, a 40V mower, and an existing charger who want to mow straight through without pausing to recharge.
A Better Fit Elsewhere
The Forrat 40V with Charger (Item 5) covers first-time 40V shoppers who need a charger and don’t already own one.
This Hanaix pack targets the oldest corner of the Black + Decker cordless world: 12V Ni-MH (nickel-metal hydride) tools like the A1712, FS120B, and FSB12 families. Ni-MH is an older chemistry than lithium-ion, but for the 12V HPB12 platform it’s the right match. The 4500mAh rating gives roughly 40% more runtime than standard replacements from the era, so older tools feel less anemic than they did with their original cells.
This is a niche pick. Anyone without an older 12V tool should ignore it entirely and look at the 20V or 40V options. But for households still using a working 12V drill, saw, or trimmer, this keeps the system functional without an overhaul.
A Few Highlights
- 4500mAh capacity provides meaningfully more runtime than standard HPB12 replacements.
- Ni-MH chemistry is the correct match for older 12V Black + Decker tools designed around that cell type.
- Broad compatibility with the A12, A1712, FS120B, and FSB12 families.
Some Limits To Know
- Ni-MH cells self-discharge faster than lithium-ion, so stored spares lose charge sitting on the shelf.
- This is a third-party pack, so warranty support runs through Hanaix rather than Black + Decker.
Key Product Details
Perfect Match For
Anyone still using a working 12V Black + Decker or Firestorm tool from the older Ni-MH generation who needs a replacement cell.
Consider Something Else When
The Qwenoer 18V 6.0Ah replacement (Item 3) is the right call for anyone whose legacy tool runs on the newer 18V platform instead.
NEPOWILL’s twin-pack design splits the difference between capacity and quantity: two 3.5Ah cells at 20V (70Wh each), covering the LBXR20, LB20, LBX20, and LBX2020 model families. For shoppers building out a 20V fleet from the tool-only side, this is often the smartest dollar per amp-hour play. One pack drives the mower while the second charges, and the rotating pair carries the whole weekend’s yard work without buying a second charger.
Capacity per cell lands between the BLACK+DECKER 1.5Ah and 4Ah OEM options from earlier in this list. Owners who already have a working 20V MAX charger get the best of both worlds here: more runtime than the lean starter, two packs, and a reasonable total outlay.
Positive Takeaways
- Two-pack format enables continuous rotation during mowing or multi-tool yard sessions.
- 70Wh per cell beats the OEM 1.5Ah pack’s runtime while costing less than the OEM 4Ah single pack in many cases.
- Compatibility covers the LCS1020 and LDX20C tool families, extending beyond just mowers.
Where It Is Less Suited
- Charger not included, so this only works for households that already own a compatible 20V charger.
- Third-party brand, so capacity fade over multiple seasons is less predictable than OEM packs.
Who Should Grab It
Shoppers already running 20V MAX tools who want a second pack for hot-swapping without paying the OEM premium.
Not Your Match When
The BLACK+DECKER 20V MAX 4Ah (Item 2) is the better choice for someone who wants one larger OEM cell rather than two third-party packs.
Picking The Right Battery For Your Mower
Voltage is the single most important filter when shopping for a replacement. Black + Decker runs four distinct cordless platforms (12V Ni-MH, 18V, 20V MAX, and 40V MAX), and a pack from one will not physically or electrically fit another. Open the battery compartment on your mower and read the label before anything else.
Capacity (measured in Ah, or amp-hours) translates directly into runtime. A 1.5Ah pack is fine for a 20-minute trim around a small yard; a 4Ah or 3.6Ah pack suits a half-acre lot. Two mid-sized packs often beat one oversized one, because the rotation keeps the work moving while the spare charges.
OEM (original equipment manufacturer) packs from Black + Decker itself carry better long-term reliability and tighter fit tolerances. Third-party replacements from brands like Forrat, Qwenoer, NEPOWILL, and Hanaix typically cost less and offer higher stated capacities, though long-term capacity retention is less certain.
Cell chemistry matters too. Lithium-ion is the modern standard and stores well through winter; Ni-MH (found in the 12V HPB12 pack) suits older tools but loses charge sitting on a shelf.
Match The Pack To Your Yard Size
Small urban lots under a quarter acre do fine with 1.5Ah to 2Ah packs. Mid-size lawns up to half an acre want at least 3Ah per pack. Anything larger benefits from two-pack rotation or the jump to 40V.
Verify The Model Number
Every platform has a list of compatible battery model numbers (LBXR20, LBX2040, HPB18, and so on). Cross-check your mower’s documentation against the replacement’s supported list before checking out.
Think About Storage And Charging
A second pack only helps if there’s a charger already in the garage. Bundle versions (like Item 5) cover first-time platform adopters; standalone packs suit households that already own a working charger.
Weigh OEM Against Third-Party
OEM packs cost more but typically last longer and fit more cleanly. Third-party packs offer higher amp-hour ratings at lower cost, with somewhat less predictable multi-year retention.
Where These Picks Differ And Where They Don’t
Across these eight packs, the real variation sits in three places: voltage platform, capacity, and whether a charger ships in the box. The OEM versus third-party split is the other meaningful divider. OEM packs (Items 1 and 2) come from Black + Decker itself, while the rest are aftermarket replacements targeting the same platforms.
Common Shopping Slip Ups
The single biggest mistake is buying across voltage families. An 18V pack will not fit a 20V MAX tool, even though the model numbers look similar. The second is assuming a higher Ah rating always wins; sometimes a two-pack rotation covers more ground than one oversized cell. Third is overlooking charger compatibility, since buying a battery without the matching charger leaves the system dead in the garage.
What The Higher Tier Buys
The OEM 4Ah pack costs more than the entry 1.5Ah option for a reason: more cells, longer runtime, tighter fit, and longer expected service life. The 40V platform costs more than the 20V platform because it drives heavier mowers and more demanding tools. The upgrade is worth it when the mower regularly needs to finish a long cutting session, push through thicker grass, or power a string trimmer for an extended edging job. On a postage-stamp lawn, the premium rarely pays back.
Frequently Asked Questions
How do I know which voltage battery fits my Black and Decker mower?
Check the label on the existing battery, the model number on the mower itself, or the operator’s manual. Black + Decker uses 12V (older Ni-MH), 18V, 20V MAX, and 40V MAX platforms, and the packs are not interchangeable across them.
Can I use a higher amp-hour battery than the original?
Yes, as long as the voltage matches. A higher Ah rating means more runtime per charge and no harm to the tool. The pack will be physically larger and slightly heavier.
Are third-party replacement batteries safe to use?
Aftermarket packs from established brands generally work fine for the rated cycle life, though long-term capacity fade is harder to predict than with OEM cells. Look for listings that name specific compatible model numbers and avoid packs without any compatibility list at all.
Should I store my battery on the charger between uses?
No. Storing lithium-ion cells at full charge for extended periods accelerates capacity loss. The better habit is to charge after use, unplug, and store at room temperature in a dry spot.
How long does a lithium-ion mower battery typically last?
Most lithium-ion mower packs deliver three to five years of regular residential use before noticeable capacity loss. Storage conditions, charge habits, and climate all influence the timeline.
Wrap Up
The right battery comes down to matching your mower’s voltage platform, sizing capacity to your yard, and deciding whether OEM reliability or third-party value matters more. For most homeowners starting fresh on a 20V MAX mower, the BLACK+DECKER 1.5Ah starter kit (Item 1) covers the basics cleanly. Bigger lots and serious runtime needs push toward the 4Ah OEM pack or a two-pack rotation. Legacy tool owners should focus on the dedicated replacement options rather than newer-platform packs. Pick the voltage first, capacity second, and everything else follows.