How to Compare Smartphone Battery Life Fairly

The fairest way to compare smartphone battery life is to compare runtime measured under the same workload, not battery capacity alone and not marketing claims measured under different conditions.

A 5,000 mAh battery is not automatically better than a 4,500 mAh battery. The larger battery stores more charge, but the phone may also use more power because of its display, processor, radios, software and other components. What matters to the user is the relationship between stored energy and how efficiently the device uses it.

That is why FactRated separates three questions that are often mixed together:

How long does a full charge last under a standardized workload?
How many charge/discharge cycles is the battery rated to withstand before reaching the defined capacity threshold?
How easy is it to replace or service the battery later?

A phone can perform well on one and less well on another.

Model identifier	Battery endurance	Battery cycles	Repairability index	Energy efficiency class
BLU G75G75	499 h 59 min	≥ 9,900 cycles	3.6	C
DOOGEE V Max 2V Max 2	403 h 10 min	≥ 1,000 cycles	3.45	B
DOOGEE V Max 2 ProV Max 2 Pro	403 h 10 min	≥ 1,000 cycles	3.45	B
ulefone Armor 34Armor 34	384 h 54 min	≥ 1,000 cycles	3.19	A
ulefone Armor 34 ProArmor 34 Pro	384 h 54 min	≥ 1,000 cycles	3.19	A

Data source: EPREL · Last updated: Sep 7, 2026

Start with standardized battery endurance, not mAh

Battery capacity, usually shown in milliamp-hours (mAh), tells you something about the size of the battery. It does not tell you how quickly a particular phone consumes that stored energy.

Two phones can have similar battery capacities but very different runtimes. Likewise, a phone with a smaller battery can outlast a model with a larger battery if it uses less energy during the same workload.

For covered smartphones, the EU energy-labelling framework defines a standardized battery-endurance test. The phone starts fully charged and runs through a repeated mix of activities until it powers off. The test includes activities such as calling, web browsing, video streaming, gaming, data transfer, video playback and idle periods under controlled settings.

Because the workload is defined, the resulting endurance value is much more useful for cross-model comparison than unrelated manufacturer claims such as "up to two days" or "all-day battery."

FactRated stores the canonical endurance value in minutes and converts it to hours and minutes for display.

What the standardized number does — and does not — mean

Suppose one phone has a registered endurance of 52 hours and another has 44 hours.

Under the standardized test framework, the first model ran longer before shutdown. That is meaningful comparative evidence.

It does not mean every owner will get exactly 52 hours between charges.

Real use can change substantially because of:

display brightness;
mobile-signal quality;
Wi-Fi and cellular activity;
apps running in the foreground or background;
navigation and location services;
camera use;
gaming load;
operating-system behavior;
temperature;
battery age;
accessories and connected devices.

The standardized result is best treated as a common ruler. It helps answer: which model lasts longer when tested under the same defined conditions?

It does not predict every individual's daily routine.

Do not confuse runtime with battery longevity

A long-lasting charge and a long-lasting battery are different things.

Battery endurance per cycle describes runtime from a full charge to shutdown under the standardized workload.

Battery endurance in cycles describes how many charge/discharge cycles the battery is rated to withstand before its usable capacity reaches the defined 80% threshold.

A phone can rank highly for runtime but have a lower cycle rating than another phone. If you expect to keep a device for several years, both measurements are worth checking.

See smartphones ranked by battery-cycle durability

Do not treat the registered cycle rating as a plug-in counter

The registered battery-cycle value is produced by a standardized charge/discharge durability test until the battery reaches the defined 80% remaining-capacity threshold. It is not a record of how many times an owner can connect a charger.

Real-world users recharge at different battery levels and under different conditions, so FactRated does not convert the laboratory cycle rating into a promised number of charging sessions or calendar years.

Use the cycle value for what it is good at: comparing standardized long-term battery durability between models.

Check battery replaceability and repairability too

If long ownership is the goal, battery performance should not be evaluated in isolation.

FactRated can also show whether the registered model identifies the battery as user-replaceable, along with its repairability index/class and repair-information fields where available.

A battery that eventually degrades is less disruptive if replacement is straightforward and spare-parts/support information remains available.

That does not make every replaceable-battery phone automatically better. Water protection, device construction, availability of replacement parts and the rest of the phone's design still matter.

The useful question is not "replaceable or not?" by itself. It is:

How does this phone combine runtime, battery-cycle durability, repairability and long-term support?

Compare phones within the same test category

FactRated keeps smartphone and slate-tablet battery rankings separate.

The standardized battery workload used for a smartphone is not identical to the workload used for a slate tablet. Mixing the raw runtimes into one league table would make the ranking look simpler while making the comparison less honest.

For the same reason, a 60-hour tablet result should not automatically be read as equivalent to a 60-hour smartphone result.

Use energy efficiency as a separate signal

Energy-efficiency class is also related to battery performance, but it is not a synonym for runtime.

The applicable smartphone energy-efficiency index relates standardized endurance to the energy available from the battery. A phone can therefore have a long runtime because it carries a large battery, while another can use its battery energy more efficiently.

If you care about runtime, look at battery endurance. If you care about efficiency, look at the energy class. If you care about long-term battery wear, look at cycle durability.

Do not substitute one for the others.

A practical battery-comparison checklist

When comparing two smartphones, use this order:

1. Standardized battery endurance

Which model lasts longer under the same defined workload?

2. Battery-cycle durability

Which battery is rated for more charge/discharge cycles before reaching the capacity threshold?

3. Battery replaceability

Can the battery be replaced by the user according to the registered product data?

4. Repairability

How does the device score on the broader repairability index and class?

5. Energy efficiency

How efficiently does the product turn battery energy into standardized runtime?

6. Your own use case

A standardized test cannot know whether you spend your day gaming, navigating, making calls or leaving the phone mostly idle. Use the standardized result to compare products consistently, then apply your own priorities.

Finder →

Why FactRated does not turn battery data into one score

It would be easy to create a single "Battery Score" by assigning weights to runtime, cycle count, capacity and replaceability.

The problem is that the weights would be subjective.

A traveler may care overwhelmingly about runtime per charge. A person who keeps phones for six years may prioritize cycle life and repairability. Someone who can charge at a desk every day may value those dimensions differently.

FactRated therefore keeps the measurements separate and lets users filter or compare them directly.

Frequently asked questions

Does a bigger mAh number mean better battery life?

No. A larger rated capacity means the battery stores more charge, but the device can also consume more power. Standardized runtime is a more direct cross-model measure of how long the phone lasts under the defined test workload.

Is standardized battery endurance the same as screen-on time?

No. The standardized smartphone workload includes a mixture of active tasks and idle periods. It is not a continuous display-on benchmark.

Can I compare Android and iPhone models using the standardized endurance value?

If both models are covered by the same standardized smartphone test framework, the metric is designed to provide a common comparison basis. Their real-world behavior can still differ by apps, settings and individual usage.

Why can my phone last less than the registered endurance value?

The test uses controlled conditions and a defined workload. Your brightness, signal strength, applications, temperature, network use and other settings can increase energy consumption.

Which matters more: runtime or cycle life?

Neither is universally more important. Runtime describes how long one charge lasts; cycle life describes longer-term battery durability. Compare both if long ownership matters to you.

Related FactRated pages

Sources and methodology

This guide is based on the standardized smartphone/slate-tablet framework in Commission Delegated Regulation (EU) 2023/1669, Commission Regulation (EU) 2023/1670 and European Commission consumer guidance for smartphone/tablet energy labelling. FactRated displays normalized registered source data and did not perform the laboratory tests itself.

Data source: EPREL · Last updated: Sep 7, 2026