AL-KO B50 20V Replacement Battery 2000mAh Li-ion Easy Flex
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AL-KO B50 20V Replacement Battery 2000mAh Li-ion Easy Flex - is backordered and will ship as soon as it is back in stock.
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Battery Care Tips
Battery Care Tips
🔹 Getting Started
Charge your new battery fully before you use it for the first time. Over the next few charge cycles, run your device down to around 20% before you recharge—this helps the battery perform its best. After that, charge whenever you need to.
🔹 Keep It Healthy
Avoid letting your battery completely drain or staying plugged in constantly. Both extremes wear it out faster. Store the battery in a cool, dry place when you're not using it, since heat damages batteries quickly.
Delivery and Shipping
Delivery and Shipping
🔹 Most orders ship the next day, and we use FedEx, UPS, Purolator and other carriers to get them to you. Lithium batteries have to ship by ground only, not air or USPS. Make sure your address is right before you order, because if we have to send it back, you pay for shipping again.
Disclaimer
Disclaimer
⚠️ Disclaimer: All product names, trademarks, and registered trademarks belong to their respective owners.
🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.
AL-KO B50 20V Replacement Battery 2000mAh Li-ion Easy Flex - is backordered and will ship as soon as it is back in stock.
Voltage
20V
Amp
2000mAh
AL-KO Easy Flex Series — 20V Li-ion Replacement Battery (B50)
This is a 20V, 2000mAh (40Wh) lithium-ion battery compatible with the AL-KO Easy Flex platform. It fits the Easy Flex 34.8 Li Lawnmower, GT 2025 Grass Trimmer, HT 2050 Hedge Trimmer, HTA 2050 Long Reach Hedge Trimmer, and 30+ other Easy Flex tools that accept the B50 pack. OEM part numbers: B50, 113559, Easy Flex B50.
- Easy Flex platform compatibility: All tools listed share the same 20V rail, B50 form factor, and BMS handshake protocol. The connector and latch geometry are identical across the range, so one pack works across the full Easy Flex line without adapters.
- Bench tested on actual hardware: We ran this pack through repeated charge and load cycles on Easy Flex platform tools. The BMS handled motor-start inrush current without tripping, held voltage under sustained cutting load, and communicated correctly with the AL-KO charger throughout.
- Lawnmower blade-start conditioning: On first use, mow two passes at a moderate pace before tackling thick or wet grass. This lets the BMS log the blade motor's inrush current spike and calibrate its overcurrent threshold before you push it into heavy-resistance cutting.
BMS cutoff on blade motor start inrush — why the 34.8 Li trips mid-lawn
When the blade engages, the motor draws a short inrush spike — often three to five times the running current — before it reaches speed. A BMS that hasn't profiled this tool will sometimes read that spike as a fault and cut power instantly. This is not a dead battery; it is an overcurrent protection trigger. Two or three normal start cycles allow the BMS to adjust its threshold, and the cutouts stop. If the problem persists after conditioning, check that the pack contacts are clean and fully seated in the tool's battery slot.
Charger blinking red on a new B50 pack after storage
Li-ion cells drop below the charger's acceptance voltage during extended storage — typically under 2.5V per cell. When that happens, the AL-KO charger sees the pack as faulty and blinks red instead of beginning a normal charge cycle. Some chargers include a recovery or "boost" mode that trickle-charges at low current until the cells climb above the acceptance threshold. If your charger lacks this mode, a compatible charger with boost function can recover the pack. Target cell voltage for normal charge acceptance is approximately 3.0V per cell or above.
Compatible Models
Replaces Part Numbers
Technical Specifications
Product Highlights
- Brand: AL-KO
- Manufacturer: CS
- Series: Standard
- Color: Black
- Product Type: Li-ion
- Battery Type: Li-ion
- Warranty: 12 Months
- Bulk Orders: sales@batteryweb.com
Frequently Asked Questions
My AL-KO Easy Flex lawnmower cuts out the instant the blade tries to spin — is the battery faulty?
Almost certainly not faulty — this is a BMS overcurrent trip triggered by the blade motor's start-up inrush spike. The protection circuit cuts power before the motor reaches running speed because it hasn't yet profiled that load. Run two or three gentle start cycles on a clear patch of grass to let the BMS calibrate its threshold. If the cutouts stop after that, the pack is working correctly.
The lawnmower runs fine for the first few minutes then starts to bog and lose blade speed — what's happening?
This is voltage sag under sustained load, not a capacity problem. As the cells heat up and internal resistance rises, the voltage rail drops enough for the motor to lose torque. Check that the battery contacts on both the pack and the tool are clean and free of grass debris — high contact resistance makes sag significantly worse. If the contacts are clean and sag still happens early in the cut, fully charge the pack and confirm you're seeing a true 20V reading at the terminal before use.
The B50 battery works fine in warm weather but the lawnmower feels sluggish on cold mornings — is something wrong?
Nothing is wrong — Li-ion internal resistance rises sharply below 5°C, which reduces the current the cells can deliver and causes noticeable power loss. Bring the pack indoors for 30 minutes before mowing on cold days. Even warming it to around 15–18°C is enough to restore normal cell conductivity and blade speed.
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