keyword is video playback battery life

Steel Shell Batteries (SUS CAN) use stainless steel casings to improve energy density, allowing longer battery life or smaller designs, and support faster charging.
They reduce swelling, enhancing safety and durability, as stainless steel resists corrosion and damage.
This is promising for Samsung devices like the Galaxy S26, potentially improving reliability.
However, steel is heavier than aluminum, possibly increasing device weight slightly, and production costs may rise.
While safety features like pressure valves mitigate risks, manufacturing challenges could delay benefits.
Overall, it’s a positive step, but weight and cost trade-offs need monitoring.

Agreed. 
A lot of variables to consider when testing the battery. Just take the results with a pinch of salt. 

keyword is video playback battery life

That's why it's impossible a 3900mah can match a 6000mah Fon IRL usage

I speculate that the battery of Samsung S26 Ultra has increased energy density, and the 5000mAh battery is smaller in size, but Samsung did not use the extra space to increase the battery, but continued to reduce the thickness of the body. I also think that the charging power of the S26 Ultra has finally been substantially improved because they used new technology to reduce the temperature of the battery during charging.

Agree! 

That means S26 ultra will have faster charging but same 5000mah battery. Meanwhile just now iqoo z 10 just started selling at RM 1228 with a 7300mah & 90W fast charging

The mystery behind why Samsung, Apple, and Google don’t significantly increase battery sizes has been solved, with the primary reason being U.S. federal regulations on lithium battery transportation, 49 CFR 173.185: For lithium-ion battery cells, the limit is 20 Wh.

Overview of Battery Capacities for Major Flagship Phones in the U.S. Market

The battery capacities of major flagship phone brands in the U.S. market (Apple, Samsung, Google, Motorola, OnePlus, Sony, etc.) are as follows (converted to Wh for comparison with regulations):

Apple:
iPhone 16 / 16 Pro / 16 Pro Max: Battery capacity approximately 3355–4702mAh, voltage typically 3.8V.
Calculation: Wh = (mAh × V) ÷ 1000
3355mAh × 3.8V ÷ 1000 ≈ 12.75 Wh
4702mAh × 3.8V ÷ 1000 ≈ 17.87 Wh 

Samsung:
Galaxy S25 / S25+ / S25 Ultra: 4000–5000mAh, voltage approximately 3.85V.
4000mAh × 3.85V ÷ 1000 ≈ 15.4 Wh
5000mAh × 3.88V ÷ 1000 ≈ 19.4 Wh 
Galaxy Z Fold 6 / Z Flip 6: 4000–4400mAh, approximately 15.4–16.94 Wh. 

Google:
Pixel 9 / 9 Pro / 9 Pro XL: 4700–5100mAh, voltage approximately 3.85V.
5060mAh × 3.89V ÷ 1000 ≈ 19.68 Wh 

Motorola: Razr Ultra:
4700mAh, approximately 18.1 Wh.
Edge 50 Ultra: 4400mAh, approximately 16.94 Wh.

OnePlus: OnePlus 13: 6000mAh, voltage approximately 3.87V, approximately 23.22 Wh, but uses a dual-cell design, with each cell not exceeding 20 Wh. 

Sony: Xperia 1 VII: 5000mAh, voltage approximately 3.85V, approximately 19.25 Wh

Ultimate Decryption: Why are the batteries of Apple, Samsung, Google, and Sony's flagship phones unwilling to exceed 5000mAh?
And why are the batteries of some overseas versions of Chinese flagship phones reduced?

Here are the reasons:

Specific Aviation Transport RegulationsKey FindingsResearch indicates that the primary reason for smaller battery capacities in overseas versions of Chinese smartphones is aviation transport regulations, particularly restrictions on watt-hour (Wh) ratings of lithium batteries.
These regulations appear to encourage manufacturers to use smaller batteries to simplify compliance and reduce costs during export.
Evidence supports aviation transport regulations as a contributing factor, though market preferences and cost optimization may also play roles.

Background
Chinese smartphones often feature reduced battery capacities in their overseas versions, potentially due to aviation transport regulations that impose strict restrictions on lithium battery shipments, especially during export.

Impact of Aviation Transport Regulations Aviation transport regulations, primarily governed by 49 CFR 173.185 (U.S. Code of Federal Regulations) and the International Air Transport Association (IATA) Dangerous Goods Regulations (DGR), set limits on lithium battery watt-hour (Wh) ratings and transport conditions:49 CFR 173.185
Regulations Under 49 CFR 173.185, lithium battery transport is categorized with specific attention to the distinction between battery cells and batteries:

Definitions: A battery may consist of one or more cells, but smartphone batteries are typically treated as a single cell.
Exceptions (49 CFR 173.185©(1)): For small lithium batteries, including those contained in equipment, the watt-hour rating must not exceed:
Lithium-ion cells: 20 Wh
Lithium-ion batteries: 100 Wh
Lithium-metal cells: 1 gram of lithium content; lithium-metal batteries: 2 grams of lithium content.

Batteries Contained in Equipment (49 CFR 173.185(d)): Specific packaging requirements (e.g., preventing short circuits, securing batteries) apply, but watt-hour limits still align with the above thresholds for exception eligibility.

Example Calculation: Smartphone battery capacity is typically measured in milliampere-hours (mAh). Watt-hours are calculated as Wh = (mAh * nominal voltage) / 1000. Assuming a nominal voltage of 3.7V:5000 mAh battery: Wh = (5000 * 3.7) / 1000 = 18.5 Wh (below 20 Wh).
6000 mAh battery: Wh = (6000 * 3.7) / 1000 = 22.2 Wh (exceeds 20 Wh).

Batteries exceeding 20 Wh may not qualify for exceptions and may require classification as Class 9 dangerous goods, involving additional packaging and labeling requirements.
IATA Dangerous Goods Regulations (DGR)The IATA DGR aligns with 49 CFR 173.185 and specifies conditions for lithium battery transport:
For lithium batteries contained in equipment, if the battery is non-removable and the device is designed to prevent short circuits, it may be treated as non-hazardous but must meet testing standards (e.g., UN Manual of Tests and Criteria, Part III, Subsection 38.3).
Higher watt-hour-rated batteries may require transport on cargo aircraft, with batteries limited to a state of charge below 30% (e.g., starting in 2026, certain batteries must not exceed 30% state of charge or 25% indicated capacity, per IATA DGR recommendations).

Why Smaller Batteries Are Chosen
Based on these regulations, the following are potential reasons for reduced battery capacities in overseas versions:
1. Indirect Impact of Aviation Transport Regulations
Compliance Costs: Batteries exceeding 20 Wh may require transport as Class 9 dangerous goods, involving additional packaging (e.g., UN-specification packaging), labeling (e.g., “Cargo Aircraft Only”), and documentation (e.g., specific transport documents). This increases export costs and complexity.

Simplified Process: Manufacturers may opt for batteries below 20 Wh to qualify for exceptions under 49 CFR 173.185©(1), reducing transport costs and risks.
Case Example: The Asus ROG Phone 6’s 6000 mAh battery (approx. 22.2 Wh) exceeds 20 Wh, potentially requiring special handling, whereas the iPhone 14 Pro Max’s 4323 mAh battery (approx. 16.68 Wh) falls within the limit, simplifying transport.

2. Market Demand and User PreferencesOverseas markets (e.g., Europe and the U.S.) may prioritize slim designs, making smaller batteries more appealing.
Compared to the Chinese market, overseas users may have lower battery life demands due to different usage patterns (e.g., less intensive gaming or video consumption).

3. Cost Optimization
Smaller batteries may reduce production and supply chain costs, particularly by simplifying logistics and compliance during export.
Pricing strategies in different markets may also lead manufacturers to adjust hardware configurations, including battery capacity, to balance cost and performance.

Maybe these tweets can shed some light on the battery mAh. 

But iqoo z10 just launched here yesterday with massive 7300mah !!! This can't be right man. Only applies to USA?

So from now on, in addition to complaining about the small battery, I suggest that you ask the United States to revise its aviation regulations.
This is the root cause. Expensive additional packaging and shipping costs make Apple and Samsung pay a higher price.
This problem is almost non-existent for Chinese brands because they are not sold in the US market, except for a few models.
So mobile phones in the Chinese market can use larger batteries.

Any upcoming offer 25U at RM4.5K? for 512g

Maybe like this ka? 

I think the Galaxy S25 Edge is the perfect phone when it comes to the form factor.

✅ Ideal size
✅ Flat screen
✅ Extremely thin
✅ Super light
✅ Ultra-thin symmetrical bezels

I love how so many design aspects of this phone is pretty much ideal.
It is the only strong point of this phone.

An interesting fact: by the end of May, the Galaxy S25 series had sold 16.61 million units (4.86 million base models, 3.17 million Plus models, 8.39 million Ultra models, and 190,000 Edge models).
All of them are equipped with the Snapdragon 8 Elite for Galaxy (4.47GHz).
Meanwhile, the total sales of all smartphones using the standard Snapdragon 8 Elite still haven’t reached 16.61 million.
This means the Snapdragon 8 Elite for Galaxy is actually the mainstream version driving shipments of this generation’s Snapdragon 8 Elite chip.

These photos were captured using the Galaxy S25 Edge, but the first one was captured using auto mode and the second one was captured using night mode.
At this point, Samsung’s night mode processing has to be improved significantly.
It is not a sensor problem. This has to be a processing problem.

S25 series 16.61 millions units, meaning Oppo realme OnePlus Xiaomi Vivo honor combined also lose to S25 series sales ? Sounds unbelievable man