LepoGarmin's gauge · Lepo's equivalent
Body Battery for Apple Watch
Body Battery belongs to Garmin, it is measured by Garmin hardware, and there is no version of it for an Apple Watch. What there is: Lepo's Energy score — the same idea, a number that starts the morning charged and spends the day draining and recovering — computed from what your Apple Watch has already recorded, with the reasons for its movement named on the screen.
Garmin's feature
What Body Battery is
Body Battery is Garmin's energy gauge. Garmin describes it as a feature available on many Garmin wearables that estimates your energy reserves through the day, using heart rate variability, stress, sleep and activity levels to produce a score from 5 to 100.
It is a running total rather than a morning verdict, and Garmin's own account of the shape of a day is the clearest statement of that: your Body Battery is fullest when you wake, activity and stress drain it through the day, naps and restful moments slow that or reverse it, and a good night's sleep is the single greatest chance to recharge. Garmin says the feature works by continuously analysing combinations of heart rate, heart rate variability and movement data while you wear the device, and that both the intensity and the duration of an effort decide how fast it drains.
In Garmin Connect the day is summarised as Charged and Drained — how much energy your body recovered and how much it used — calculated over 24 hours and reset at midnight. Garmin also says a new or factory-reset device needs a learning period, typically five to seven days, before it has a personal baseline to score against.
Every sentence above is from Garmin's own published pages: Body Battery Energy Monitoring and the Body Battery frequently asked questions. There is nothing here about how the algorithm arrives at its number, because Garmin does not publish that, and a guess at a competitor's method would be worth less to you than the admission.
On an Apple Watch
Why there is no Body Battery for Apple Watch
Two reasons, and the second is the one that surprises people.
The first is the hardware. Body Battery is measured by a Garmin device on your wrist, and Garmin is explicit that data from devices which do not support the feature is not included in its calculations, and that the estimate is only as good as how consistently you wear a device that does. An Apple Watch is not one of those devices, and no app can make it into one.
The second is that the number does not travel, even if you own both. Garmin publishes the list of what Garmin Connect can share with Apple Health: active energy, body fat percentage, body mass index, flights climbed, heart rate, resting energy, sleep analysis, steps, walking and running distance, water, weight, and workouts. Body Battery is not on that list. Neither is heart rate variability, nor resting heart rate. Garmin also notes the sync only runs one way — Connect pushes into Apple Health and does not pull anything back out of it.
Body Battery does leave Garmin's own apps by one route, and it is not a route open to an app like this one. Garmin's Connect Developer Program carries Body Battery in its Health API, and Garmin describes that program as being for enterprise and business use, granted on application, with a licence fee on some metrics for commercial use. Lepo does not use it.
So Lepo cannot import a Body Battery value from a Garmin. No app reading Apple Health can, because the value is never written there. What an app on your phone can do is compute the same kind of number from the signals your own watch does record.
Sources, same reading: Sharing your Garmin Connect data with Apple Health, and Garmin's Health API and developer program FAQ.
Lepo's answer
Lepo's Energy score, on the watch you already own
Energy is Lepo's running score for the day, on the same 5 to 100 range as the gauge it resembles. It is anchored each morning to that day's Readiness — mostly the new morning's score, with a little of yesterday's energy carried across rather than a hard reset — and then moves as the day does: draining with exertion and stress, charging back through quiet stretches, naps and sleep. Lepo sorts the day into those states from your heart rate and your recorded workouts, and prices each one.
What it will not do is fill in. Energy refuses to score a day with no real Readiness behind it, and it needs heart-rate or workout data in the window to draw at all; where the recorded data stops, the line stops too. A day the watch spent on the charger comes out as a gap rather than as a plausible curve nobody measured, and the next morning with a Readiness score starts again from that score instead of carrying the unknown day forward.
The difference: the score shows its reasons
Lepo gives you the number and then names what moved it. The Energy screen lists the drivers behind the score — the morning's Readiness anchor, the recovery accumulated so far, the drain against it, the share of the day spent in a stressed state, and the active minutes underneath — each with its own reading and a worded verdict: Supports, Limits or Neutral, or, for activity, "Uses energy", because spending energy on a run is not a fault in the day. With Pro each row also says what that reading usually is by this hour, measured against the median of your own earlier days at the same time rather than against a population.
One bound on that, because "shows its reasons" is easy to overstate. An Energy row carries a worded verdict and never a signed contribution to the score: energy is a charge-and-drain model rather than a sum of weighted signals, so there is no honest "+11 pts" to print beside a driver. Those signed per-signal impacts do exist in Lepo — on the Readiness and Sleep screens, where the score really is a weighted sum — and they are a Pro detail.
Both directions
An honest comparison
| Garmin Body Battery | Lepo Energy | |
|---|---|---|
| Measured by | Garmin's own sensors, including its all-day stress metric, which Lepo has no equivalent of | Nothing of Lepo's. It reads what is already in Apple Health |
| Where you see it | The Garmin watch itself, all day, and Garmin Connect | iPhone, Apple Watch, watch face complications, Home Screen widget |
| History | Kept in a Garmin Connect account | Seven days free on both devices; thirty on iPhone with Pro |
| Your first day | A new or reset device learns your baseline first — five to seven days, Garmin says | Reads up to thirty days already in Health, so the first morning can be a real score against your own history |
| Why it moved | Charged and Drained totals for the day | Every driver named, each with a worded verdict; with Pro, each against your own earlier days at the same hour |
| What it needs | A Garmin device and a Garmin Connect account | No account. Read-only Health access, computed on the device |
| If you wear a Garmin | Body Battery goes on working. It is what the device is for | Lepo gets less out of it than out of an Apple Watch — see below |
That last row in full, because a comparison that only lists what Lepo wins is not one. On a Garmin, Lepo sees raw heart rate but neither HRV nor resting heart rate, so readiness runs on an estimated resting rate — labelled "(est.)" in the app — with no HRV row and no HRV trend. A timed activity sends only its high and low heart rate, so exercise drain leans on duration and active energy instead. And Garmin Connect only pushes to Apple Health while it is open, which makes a stale reading likelier than with any other brand.
Where Pro comes into that: everything above that describes Energy is free — the three scores every morning, their reasons in plain language, seven days of history on both devices, the complications and the Home Screen widget, and the morning notification. Pro adds the evidence: each signal's point impact and its baseline comparison, the strain, workout, nap and sleep-window detail on the graph, thirty days of history on iPhone, the evening summary, the sleep bank, and five more themes. The homepage's Free and Pro section lists both sides.
If you want to see the rest of it
The homepage's Three scores section says what Readiness, Sleep and Energy each read, and What moved it walks through a real readiness breakdown row by row — that is the screen where the point impacts live. Anything this page did not answer can go to a person: the support page has the address.
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Lepo is an independent app. It is not affiliated with, endorsed by, or sponsored by Garmin. Body Battery is Garmin's feature and Garmin's name for it; it is used here to compare, and nothing Lepo does is called by that name.
Comparison checked against Garmin's current documentation 11 September 2026 · Page last updated 11 September 2026