Intel MacBook Pro shows incorrect battery power while charging

[ama156]

Describe the bug

On my 2019 16-inch Intel MacBook Pro (MacBookPro16,1), Stats reports an incorrect battery power value while the battery is actively charging.

For example, while charging I see:

• Battery current: 4471 mA
• Battery voltage: 12.43 V
• Battery power shown by Stats: 0.19 W
• Power adapter input: 81.15 W / 94 W
• Adapter voltage: 20.00 V
• Adapter current: 4057 mA

The battery voltage and current indicate that the battery is actually charging at approximately:

12.43 V × 4.471 A ≈ 55.6 W

So the displayed 0.19 W battery power value does not represent the actual charging power.

Cause

I traced this to Modules/Battery/readers.swift.

The current code prefers the PPBR SMC value:

self.usage.batteryPower = SMC.shared.getValue("PPBR") ?? (self.usage.voltage * (Double(self.usage.current) / 1000))

On this Intel Mac, PPBR remains around 0.2 W while the battery is actively charging.

It appears that PPBR on this model represents battery discharge-side power rather than power being delivered into the battery. Because the SMC key exists, Stats never falls back to calculating battery power from battery voltage × current.

Proposed fix

For Intel Macs while connected to AC power, use battery voltage × current to calculate charging power.

Keep the existing PPBR behavior when running from battery and keep the existing behavior unchanged on Apple Silicon.

I tested this change locally:

let calculatedBatteryPower =
    self.usage.voltage * (Double(self.usage.current) / 1000)

if !isARM && !self.usage.isBatteryPowered {
    self.usage.batteryPower = calculatedBatteryPower
} else {
    self.usage.batteryPower =
        SMC.shared.getValue("PPBR") ?? calculatedBatteryPower
}

With this change, the Battery popup reports the expected charging power (~55 W in the example above) instead of ~0.19 W.

I also tested running from battery to make sure the existing PPBR discharge-power behavior is preserved.

I have the tested change committed in my fork and can provide the commit/branch. I attempted to open a PR, but pull requests to this repository are currently restricted to collaborators.

Steps to reproduce

1. Use an Intel MacBook Pro with a partially discharged battery.
2. Connect a sufficiently powerful USB-C charger.
3. Open Stats → Battery.
4. Observe that the battery has several amps of charging current, but Battery → Power remains around 0.2 W.
5. Compare the displayed value with battery Voltage × Current.

Details:

• Device: MacBook Pro 16-inch, 2019 (MacBookPro16,1, Intel)
• macOS: 26.5.2
• Application version: 3.0.13

Screenshots

Before Fix:

After Fix:

[santhiprakash]

I have looked into this issue and found that the local changes in Modules/Battery/readers.swift match the proposed fix. The change ensures that when on AC power, the battery power is calculated from voltage and current, which should resolve the incorrect reading on Intel Macs while charging.\n\nWould you like me to proceed with submitting this change? (Note: I cannot open a PR directly due to restrictions, but I can share the diff here or via a fork if needed.)

[santhiprakash]

I have left a comment with a proposed fix. I am now awaiting feedback from the maintainer to proceed. Please let me know if the fix looks correct or if any changes are needed.