Why Big Brands Still Avoid Massive Smartphone Batteries?
BY Sabeeh Zanair :
Chinese smartphone brands such as Xiaomi, Oppo, and OnePlus have moved aggressively toward much larger battery capacities in recent years. However, this trend has not been widely adopted by major global players like Apple, Samsung, and Google, whose flagship phones continue to use relatively modest battery sizes.
A key reason appears to be logistics rather than technology. According to well-known tipster Ice Universe, the main barrier is US transportation law — specifically regulations governing the shipment of lithium-ion batteries.
The 20Wh Rule Explained
In the United States, lithium battery shipping is regulated under federal code 49 CFR 173.185, alongside international aviation safety rules. These guidelines classify lithium-ion cells based on their energy capacity.
If a battery cell is rated at 20 watt-hours (Wh) or less, it can be transported under simplified rules. Once a battery exceeds that threshold, it falls into a higher-risk category and must follow stricter hazardous materials procedures.
These higher classifications require special packaging, labeling, and documentation, which significantly increases shipping complexity and costs for manufacturers.
Since smartphone batteries are typically treated as single lithium-ion cells, companies deliberately design them to stay below this limit in order to avoid regulatory complications.
How Battery Size Is Calculated
Battery energy capacity is calculated using this formula:
Watt-hours (Wh) = (milliamp-hours (mAh) × Voltage) ÷ 1000
Most smartphone batteries operate between 3.7V and 3.85V, which means:
- 4000 mAh ≈ 15–16 Wh
- 5000 mAh ≈ 19–20 Wh
- 5500 mAh ≈ over 21 Wh
- 6000 mAh ≈ over 23 Wh
This shows why pushing beyond 5000 mAh in a single cell quickly crosses the regulatory threshold.
Flagship Phones Stay Safely Below the Line
Battery specifications from major brands reflect this limitation:
- Apple’s iPhone 16 lineup uses batteries ranging roughly from 3300 mAh to 4700 mAh, staying well under 18 Wh.
- Samsung’s Galaxy S25 series features batteries between 4000 mAh and 5000 mAh, topping out near 19.5 Wh.
- Google’s Pixel 9 models sit close to the upper boundary at just under 20 Wh.
All remain within the transport-friendly category.
How Some Brands Work Around It
To deliver larger batteries without violating shipping rules, some manufacturers use dual-cell designs.
Instead of one large battery, the phone contains two smaller cells wired together. Each individual cell stays under 20 Wh, but the combined total capacity is much higher.
For instance, phones like the OnePlus 13 use this method to reach around 6000 mAh overall, while still complying with international transport regulations.
The Real Reason Battery Growth Is Slow
In short, the lack of massive batteries in premium phones isn’t due to engineering limitations. It’s largely a matter of global logistics, legal compliance, and shipping economics.
Until regulations change — or dual-cell designs become standard — most major brands will continue to play it safe and keep their batteries just under the invisible 20Wh line.
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