Mighty Max Battery 12V 18AH SLA Replaces Black & Decker CMM1000 Cordless Mulching Mower

What It Is

This is a 12-volt, 18 amp-hour sealed lead-acid (SLA) replacement battery designed to power the Black & Decker CMM1000 cordless mulching mower and similar 12V electric lawn mowers. It provides the stored energy needed to run the mower’s motor without a cord, replacing the original battery when it no longer holds a charge.

Fitment & Compatibility

Before buying, verify these three things:

• Model fit: This battery directly replaces the Black & Decker CMM1000 battery. It may also fit other 12V cordless mowers (e.g., some older Craftsman, Ryobi, or Neuton models), but always check your mower’s voltage and battery compartment dimensions.
• Dimensions: The battery measures 7.1 x 3.0 x 6.7 inches (L x W x H). Measure your existing battery or the compartment to ensure it fits snugly. The CMM1000 uses a specific terminal layout—confirm your mower’s connectors match the battery’s F2 (0.187″) or F1 (0.250″) spade terminals.
• OEM vs aftermarket: This is an aftermarket replacement, not a Black & Decker OEM part. It will not include the mower’s battery tray or wiring harness; you reuse your existing connections.

Key Things to Know

• Quality: Mighty Max is a reputable brand for SLA batteries. The 18Ah rating matches the CMM1000’s original capacity, so runtime should be similar (typically 30–45 minutes on a full charge).
• Installation difficulty: Easy—disconnect the old battery, remove it, place the new one, and reconnect the spade terminals. No tools required beyond maybe a small screwdriver to loosen terminal screws. The battery is heavy (about 11 lbs), so handle with care.
• Common gotchas:
  • The battery may arrive with a partial charge; charge fully before first use.
  • If your mower has a built-in charger, ensure it’s compatible with SLA batteries (most are). Some newer mowers use lithium-ion—this won’t work with those.
  • Terminal orientation matters: the positive and negative posts are on opposite sides. Verify your mower’s wiring reaches them.
• Maintenance: SLA batteries are sealed and maintenance-free, but store in a cool, dry place and recharge after each use to extend life.

Should You Buy It

If your Black & Decker CMM1000 or other compatible 12V mower has a dead battery and you want an affordable, reliable replacement without paying OEM prices, this is a solid choice. It’s simple to install, matches original specs, and has good reviews. Skip it if you need a lithium-ion upgrade or your mower uses a different voltage (e.g., 24V or 36V).