CRAFTSMAN 20V Power Tool Battery 2-Pack, Lithium-ion with Charger (CMCB204-2CK)

What It Is

This is a 2-pack of Craftsman 20V MAX lithium-ion batteries (4.0 Ah each) plus a charger, designed to power Craftsman 20V cordless lawn mowers, trimmers, blowers, and other outdoor power tools.

Fitment & Compatibility

• Voltage & platform: Works only with Craftsman 20V MAX tools (not 40V or 60V). Check tool label for “20V MAX” or “V20.”
• Battery type: Lithium-ion, slide-on mount (not post-style). Compatible with all Craftsman 20V MAX tools from 2010 onward.
• Charger: Included CMCB204 charger charges both batteries simultaneously. Works with all Craftsman 20V batteries (1.5Ah, 2.0Ah, 4.0Ah, 5.0Ah).
• OEM vs aftermarket: This is genuine Craftsman/OEM. Aftermarket batteries may have different fit or lower capacity.
• What to check: Confirm your mower or tool lists “20V MAX” on the battery port or manual. Measure battery compartment depth—4.0Ah batteries are taller than 1.5Ah ones.

Key Things to Know

• Installation: Slide battery onto tool until it clicks. No tools needed. Press release tab to remove.
• Quality: Reliable OEM cells; consistent runtime. 4.0Ah gives ~45 min on a 20V string trimmer, ~30 min on a mower.
• Gotcha: Batteries ship partially charged. Fully charge before first use (about 1 hour per battery).
• Storage: Store at 40-80°F. Avoid leaving on charger after full charge—can reduce lifespan.

Should You Buy It

Buy this if you already own or plan to buy Craftsman 20V MAX tools and need extra runtime for larger yards (1/4 acre or more). The 2-pack with charger is cost-effective compared to buying singles, and OEM reliability beats aftermarket options. Skip it if you only have one small tool or need higher voltage (40V/60V) for heavy mowing.