Battery API: Myth or Real Signal? Why Do Modern Browsers Still Allow It?

[BadB]

Analysis of the Battery Status API's relevance as a fingerprinting component in 2026

Introduction: A Ghost from the Past​

You're setting up a profile in Dolphin Anti. You see the Battery API in the list of fingerprint components. You think, "That's a deprecated API — it was disabled a long time ago!"

But in fact, the Battery Status API is still active in most browsers and is used by fraud engines as an additional trust signal.

In this article, we'll explore why the Battery API isn't dead, how it works in 2026, and whether it's worth enabling in your profile.

Part 1: What is the Battery Status API?​

Technical definition​

The Battery Status API is a web API that allows a website to retrieve information about the device's battery status:

• Charge level (0–100%),
• Power supply mode (battery or mains),
• Time to full discharge/charge.

Code example:
js:

navigator.getBattery().then(battery => {
console.log(`Charge: ${battery.level * 100}%`);
console.log(`Power: ${battery.charging ? 'network' : 'battery'}`);
});

History:
The API was introduced in 2012, but was criticized in 2015–2017 for its potential use in fingerprinting.

Part 2: Battery API Status in 2026​

Browser support​

Browser	Status	Notes
Chrome	Active	Returns dummy values (see below)
Firefox	Limited	Returns level = 1.0 (100%) always
Safari	Disabled	Completely removed from iOS 13+
Edge	Active	Similar to Chrome

Key fact:
Chrome and Edge still support the API, but return dummy, randomized values to protect privacy.

Part 3: How Fraud Engines Use the Battery API​

Two use cases​

Scenario 1: Emulation Detection

• Real users often use laptops on battery power,
• VPS/RDP are always "connected to the network",
• If Battery API is not available at all → the system marks you as a server.

Example:
Profile without Battery API → Fraud Score +15.

Scenario 2: Device Consistency

• If you claim you are using a laptop but the Battery API is not available → anomaly,
• If you are on desktop, but Battery API is available → anomaly.

Rule:
The presence/absence of API must match the device type.

Part 4: How to Configure the Battery API Properly​

B Dolphin Anty / Linken Sphere​

Parameter	Recommended value	Why
Battery API	Turn on	Only if you're simulating a laptop
Charge level	40–80%	Realistic range
Diet	"From the battery"	For laptops
Time to discharge	1–3 hours	Corresponds to actual use

If you are simulating a desktop:

• Disable Battery API completely,
• Or set it to "Connected to network".

Part 5: Why Browsers Haven't Removed the API Completely​

Reasons for preservation​

1. Legitimate use cases:
   • Video and audio apps (such as YouTube) may experience reduced quality when battery power is low,
   • Offline applications (maps, games) can warn about low battery.
2. Difficulty of removal:
   • Many websites still use APIs,
   • Complete deletion will cause errors on legitimate resources.
3. Protection through fictitious data:
   • Chrome returns randomized values, making the API useless for accurate fingerprinting.

Truth:
The API remains not because it is dangerous, but because it is now safe.

Part 6: Practical Recommendations​

When to enable Battery API:​

• You are simulating a laptop,
• You are using a mobile device,
• The target site checks for API availability (rare, but it happens).

When to disable:​

• You are simulating a desktop,
• You work on RDP/VPS (technically always “from the network”),
• You want to minimize fingerprint.

How to check:​

1. Go to https://browserleaks.com/battery
2. Make sure that:
   • API is available/not available according to your device,
   • Values are realistic (not 100% always).

Part 7: The Future of the Battery API​

Forecast for 2026–2027​

• Safari has already removed the API,
• Firefox has limited it to constant values,
• Chrome may completely disable the API by 2027.

Strategy:
Don't rely on the Battery API as a key signal, but don't ignore it as a source of anomalies.

Conclusion: Battery API is not a threat, but a detail​

The Battery Status API in 2026 is n't a powerful fingerprinting tool, but a small detail of behavioral consistency.

Its goal isn't to expose you, but to ensure your profile is consistent:

• Laptop → has a battery,
• Desktop → no battery.

Final thought:
True security isn't about disabling all APIs, but about configuring them plausibly.
Because in the world of fraud engines, even the battery needs to be plausible.

Stay consistent. Stay realistic.
And remember: in the world of fingerprinting, every detail is part of the picture.