MacBook battery history.Cycles, charges, rescues, all in context.

What the Saga page actually shows

Five panels, in order:

• Charge history chart. Flip between the last 24 hours, 3 days, or 7 days (free tier); Premium extends both windows to unlimited history. Each charge and discharge is a line; the chart annotates rescues (you plugged in within 30 minutes of a critical warning) and plateaus (long stretches at the same percent).
• Battery Health tiles. The four numbers worth knowing: maximum capacity (your battery health percentage), cycle count, current cell temperature, and the condition string macOS reports (Normal or Service Recommended).
• Top power-hungry apps. The same metric Activity Monitor uses, surfaced live right now or over the last 3 hours or 5 days — as a percentage or in watts. A search filter lets you collapse a noisy process tree — type "chrome" and every Chrome helper lines up.
• Weekly + Monthly Wrapped. Spotify-Wrapped-style recaps of how your battery did this week and this month. Cycles added, average daily depth-of-discharge, hottest day, longest unplugged stretch. Shareable as a small card.
• Rescue Receipts. When you plug in within 30 minutes of Sensei’s critical warning, the app stitches a small "save" card with the timing, the apps that were draining you, and the wattage in. A quiet record of the close calls.

Why a battery needs a story

A capacity number — "92%" — tells you almost nothing without context. Is that good for a Mac your age? Did it just drop from 95% in two weeks, or has it been holding steady? Which weeks cost you the most capacity, and what were you doing then?

Saga makes those questions answerable in seconds. The chart shows the shape of the curve; the Wrapped recaps surface the patterns; the power-hungry apps panel turns "battery died fast today" into a name you can point at. Battery health stops being a vague feeling and starts being a thing you can compare against the norm.

Privacy: nothing leaves your Mac

Every panel above reads from local sources — IOKit for charge state, Apple’s power assertions API for per-app energy impact, the battery’s own firmware counters for cycles and capacity. There’s no telemetry, no cloud sync, no account. The Wrapped recaps you share are images you create and choose to send; Sensei doesn’t see them.

The shape of Saga only makes sense if the data stays on-device, because the chart is yours — your worst week, your nearest miss, the hot Saturday that cost you 2% capacity. None of that should live anywhere else.

Where to start reading

Three useful entry points if you’re new to the page:

• Open the 7-day chart and look at the depth of each daily discharge. A healthy pattern looks like shallow troughs (you didn’t drain below 30% most days). Deep troughs mean you’re cycling the battery hard — see the charge cycle entry for why that matters.
• Read the cycle count and battery health together. The two move differently, and seeing them side-by-side is the fastest way to tell whether your laptop is aging on schedule or ahead of it.
• Skim the Weekly Wrapped on a quiet Sunday. The "hottest day" and "longest unplugged stretch" lines are usually where you’ll find the actionable insight.