Your MacBook battery is a consumable component — like the brake pads on a car, it’s designed to wear out and be replaced. The question is when, and how to spot the signs before the battery becomes a hazard.

The clearest signal: macOS itself tells you. When the battery has degraded past the point of useful life, System Settings → Battery shows a “Service Recommended” or “Service Battery” warning. That’s Apple’s own diagnostic saying the cell can no longer hold a healthy charge. At that point, replacement isn’t optional — battery health below ~80% means you’re losing the rated runtime, and below 70% the system starts throttling CPU performance to compensate.

Cycle count is the underlying metric. Every full charge from 0% to 100% (or two half-cycles, etc.) counts as one cycle. Apple rates modern MacBook batteries for ~1,000 cycles before reaching 80% capacity. You can check yours: hold Option, click the Apple logo → System Information → Power → Cycle Count. Most office users hit 1,000 cycles in 3-4 years; heavy users get there in 18-24 months.

Symptoms beyond the macOS warning:

• MacBook shuts down at 30-50% even when “charged”
• Trackpad lifts up or won’t click — that’s a swelling battery pushing the case open
• Charge stuck at a percentage that won’t move
• MacBook runs hot when charging or under light load
• Visible bulge in the case, especially under the trackpad
• Strong rotten-egg or chemical smell from the chassis (rare, but stop using the MacBook immediately if you notice this)

A swollen battery is a safety issue, not just a performance one. Swelling means the cell has degraded chemically and is generating gas; in rare cases this can lead to thermal runaway. Stop using the MacBook, do not put it in a bag or near anything flammable, and get the battery replaced — we offer same-day or next-day service for safety-critical swelling cases.

Our fixed UK-wide mail-in battery replacement service covers every MacBook from 2010 onwards. Diagnosis, parts, labour, return shipping and a 1-year warranty are all included in the per-model price. We use the same battery cells Apple specs for the chassis, your original chassis / keyboard / trackpad / display all carry over, and we recalibrate the charging circuit before return.

If you’re unsure whether your battery is the right service or whether the symptom you’re seeing is actually a logic-board fault that mimics battery wear, get in touch via the contact page and we’ll tell you what’s most likely before you book.

Phone: 01202 767 929. 612 Wimborne Road, Winton, Bournemouth, BH9 2EN.