What Does Wh Mah Mean In Battery Specifications?

Wh (watt-hour) and mAh (milliamp-hour) define battery energy and charge capacity. Wh measures total energy storage (voltage × current × time), critical for comparing devices with differing voltages. mAh indicates charge capacity but ignores voltage—useful for same-voltage systems. For example, a 10Wh (5V, 2000mAh) battery holds twice the energy of a 10Wh (10V, 1000mAh) pack despite identical mAh. Always prioritize Wh for cross-voltage energy assessments.

Milliamp Hours to Watt Hours Conversion Calculator (mAh to Wh)

Table of Contents

Wholesale lithium golf cart batteries with 10-year life? Check here.

Toggle

What’s the difference between Wh and mAh?

Wh quantifies energy capacity, while mAh measures charge capacity. Wh = Voltage (V) × Amp-hours (Ah), factoring in voltage differences. mAh simplifies charge capacity for single-voltage devices (e.g., smartphones), but ignores voltage’s role in actual energy storage.

Wh provides a voltage-adjusted energy metric, essential when comparing batteries with different voltages. For instance, a 14.8Wh (3.7V/4000mAh) phone battery stores the same energy as a 14.8Wh (7.4V/2000mAh) drone battery—though their mAh differs. Pro Tip: Use mAh only when comparing batteries with identical voltages.

Consider this analogy: mAh is like counting water molecules in a tank, while Wh measures the actual pressure (voltage) and volume (current) combined. Tables below show real-world comparisons:

Why do manufacturers use both ratings?

Manufacturers use mAh for marketing simplicity and Wh for technical accuracy. mAh is familiar to consumers (e.g., phone batteries), while Wh meets regulatory requirements (e.g., airlines’ 100Wh limit).

Want OEM lithium forklift batteries at wholesale prices? Check here.

Marketing teams prefer mAh because larger numbers attract buyers—even if voltage differences make comparisons irrelevant. However, aviation safety rules demand Wh since energy density determines fire risks. But what happens when a 20,000mAh power bank claims 74Wh? Its actual voltage is 3.7V (20Ah × 3.7V = 74Wh). Pro Tip: Divide Wh by V to find true Ah. Transitionally, this dual-rating system balances consumer appeal and technical compliance. For example, a 100Wh electric bike battery (36V/2.78Ah) and a 100Wh solar generator (12V/8.33Ah) highlight how Wh unifies energy measurement across voltages.

How do you convert mAh to Wh?

Multiply mAh by voltage (V), then divide by 1000. Formula: Wh = (mAh × V) ÷ 1000. Always confirm the battery’s nominal voltage for accurate conversions.

Take a 3000mAh battery labeled 3.7V: (3000 × 3.7) ÷ 1000 = 11.1Wh. But if the same mAh battery runs at 12V, it’s 36Wh—3.25× more energy. Pro Tip: Check device labels for voltage specs—USB banks often use 3.7V, while laptops may use 11.1V. Ever wondered why power banks list both mAh and Wh? Regulatory agencies require Wh for air travel, but manufacturers lead with mAh for consumer appeal.

For example, converting a 10,000mAh power bank: At 3.7V, it’s 37Wh (safe for flights), but miscalculating with 5V incorrectly gives 50Wh.

Why is Wh critical for solar/renewable systems?

Wh determines actual usable energy in solar setups, while mAh fails to account for varying voltages across panels and batteries. Solar systems often mix 12V/24V/48V components, making Wh essential for capacity planning.

A 100Ah 24V battery bank stores 2400Wh—twice the energy of a 100Ah 12V system. However, marketing it as “100Ah” without voltage context is misleading. Pro Tip: When sizing solar panels, match daily Wh consumption to panel wattage and sun hours. For example, a 2400Wh/day cabin needs a 600W solar array receiving 4 peak sun hours (600W × 4h = 2400Wh). Transitionally, this clarity prevents undersizing systems. But what if your inverter operates at 48V? The same 2400Wh requires just 50Ah at 48V, reducing cable costs.

Redway Battery Expert Insight

FAQs

Watt Hours to Milliamp Hours Calculator (Wh to mAh)