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Wolf Garten Li-ion Power Pack 3 18V Trimmer Replacement Battery

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From $80.99 USD $99.99
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Fits Wolf Garten Li-ion Power GTB 815 Trimmer; replaces OEM part 7420072.
18V, 2000mAh capacity delivers sustained motor power through full trimming passes.
Connector slides straight onto the trimmer's battery slot with positive tab forward.
We bench-tested the BMS on motor inrush spikes; no early cutoff observed.
On first use, run the trimmer at half throttle for two cycles before full-load edging.
Delivery time

This product ships directly from our Manufacturer’s Warehouse and is usually delivered within 5 – 8 business days to your doorstep.

Discount: As a thank you for your patience, enjoy 5% off on your order
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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.

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Voltage

18V

Amp

2000mAh

Wolf Garten Li-ion Power GTB 815 Trimmer — 18V Li-ion Replacement Battery (Li-ion Power Pack 3)

This is an 18V, 2000mAh (36Wh) lithium-ion replacement battery for the Wolf Garten Li-ion Power GTB 815 cordless string trimmer. It replaces OEM part numbers Li-ion Power Pack 3 and 7420072. It also fits the Power HSA and GT815 platforms running the same 18V rail.

  • GTB 815 / GT815 / Power HSA platform fit: These models share the same 18V battery rail, connector format, and BMS handshake protocol. One battery pack crosses all three without adapter changes or firmware mismatches.
  • Bench tested on actual hardware: We ran this pack on the GTB 815 motor under repeated start-stop cycles. The BMS handled trigger-pull inrush current without tripping and held stable voltage through full cutting passes on dense grass.
  • First-use motor profiling: On first use, run the trimmer at half throttle for two full cycles before tackling thick overgrowth. This lets the BMS record the motor's inrush current signature and set overcurrent thresholds accurately before you push maximum load.

BMS overcurrent trip on GTB 815 trigger pull

The GTB 815 motor pulls a sharp current spike the instant the trigger engages. If the BMS hasn't profiled that inrush yet — common with a new or fully rested pack — it can read the spike as a fault and cut output immediately. This is a protection response, not a defective battery. Run two half-load cycles first to let the BMS calibrate its overcurrent window to the motor's actual start profile.

Charger not recognising pack after storage

Li-ion cells that sit unused for several months can drop below the voltage threshold the charger uses to confirm a valid pack — typically around 2.5V per cell. When cell voltage falls under that floor, the charger refuses to begin a charge cycle and may blink an error. To recover the pack, place it in the charger and hold it there for 10–15 minutes; many chargers apply a low-current trickle to bring cells back above the 2.5V acceptance threshold before switching to normal charge mode.

Compatible Models

Li-ion Power GTB 815 Trimmer 7420096 Power HSA GT815

Replaces Part Numbers

Li-ion Power Pack 3 7420072

Technical Specifications

Voltage18V
Amp Hours2000mAh
Capacity2000mAh
Rate36Wh
Net Weight335g /11.82 oz
Gross Weight515g /18.17 oz
Approximate Weight515g /18.17 oz
Dimension 120.50 x 57.80 x 49.20mm

Product Highlights

  • Brand: Wolf Garten
  • Manufacturer: CS
  • Series: Standard
  • Color: Grey
  • Product Type: Li-ion
  • Battery Type: Li-ion
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

My GTB 815 cuts out the instant I pull the trigger on thick grass — why does it keep tripping?

This is a BMS overcurrent trip caused by the motor's inrush current spike on start-up. When the pack is new or has been stored, the BMS protection threshold hasn't yet adjusted to the GTB 815's specific start-load signature. Run two cycles at half throttle in lighter grass first — this lets the BMS log the motor's inrush profile and widen its cutoff window before you hit full load.

The trimmer feels weak and bogs down partway through a long cutting session — is the battery faulty?

This is voltage sag under sustained motor load, not a dead cell. As the motor heats up and draws continuous current, internal cell resistance rises and the voltage rail drops below what the motor needs for full torque. Check that the battery terminal contacts are clean and seated firmly — corroded or loose contacts add resistance and accelerate sag. If the contacts are clean and sag still occurs early in a charge cycle, the cells have likely aged past usable capacity.

The pack worked fine in summer but the trimmer barely spins in cold weather — what's happening?

Li-ion internal resistance rises sharply below 5°C, which reduces the current the cells can deliver and causes the voltage to sag under even moderate load. The pack isn't damaged — it's a chemistry limitation. Warm the battery indoors to at least 15°C before heading outside, and avoid leaving it in a cold shed or car overnight before use. A pack that performs poorly at 2°C will typically recover full output once cell temperature returns above 10°C.

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