/ Technology

How would you rate the battery life on your laptop?

Laptop battery

When we tested laptop batteries we found that barely any of them managed to meet the claims made by the manufacturers. So when you boot up your laptop, how long is it before you have to reach for the charger?

As a regular laptop user, I usually find myself with one eye constantly monitoring the battery icon. Anything above say, 70%, and I’m relatively calm. A dip below 50%, and I start to get concerned. When we reach 30% or lower, I’m already rifling through my bag for the charger, and hoping I can find a vacant plug socket before my laptop starts a fast descent into the dreaded red zone of the battery icon.

Although my laptop came with lofty claims about its battery life, I’ve never believed it. Yes, I was promised 8 hours, but I’ve never got close to that – I can barely scrape 4 before the screen blips to black.

Laptop battery life

I’ve always been suspicious about battery life, and looking back at our laptop battery tests it seems I had good reason to be.

Our research shows that the claimed battery life on the box rarely matches what you get – in some cases, users are drastically short changed.

In fact, we found that claims that we actually accurate is something of an anomaly. Not only that, but some laptops could even last half as long as they claimed.

As an example, the Lenovo Yoga 510 is advertised with a five hour battery life. We only managed two hours, seven minutes. Similarly, the Acer E15 is listed as having six hours, but our tests found it was less than three.

With the battery life being a major deciding factor when purchasing a laptop, this seems less than ideal.

Battery life tests

So why the big differences? We spoke to the manufacturers, some of which told us that they arrive at their battery estimates via dedicated benchmarking software.

While our lab testing of a laptop battery involves us laboriously surfing the web until the battery dies, before repeating the test again. We will also play a movie on the laptop until it powers down. It might not be the most fun way to spend an afternoon, but we do think it’s more representative of how people use their laptops in the real world.

While none of this changes the fact that I have to reach for my charger much more often than I would like, it does explain it.

Claims and expectations

So, when I’m next in the market for a laptop, I’ll certainly be more cynical about the claims (and check the Which? review, of course!).

However, what would be even better is if I could actually believe the claims in the first place. If you went to buy a car on the understanding you got 40 Miles Per Gallon, but only ever got 20, you’d be pretty miffed.

So why do we accept getting short changed on battery life when it comes to laptops?


This comment was removed at the request of the user

Many new laptops have a solid-state drive rather than a mechanical hard disk, which certainly helps conserve battery power. My mid-2014 MacBook Pro has a SSD and stays on all day. It powers down to conserve the battery after the default two minutes of inactivity, but as soon as the trackpad is touched or a key is pressed it is immediately ready for use. I have a charger in my lounge and another in the office and often plug in the laptop when cooking meals. I’m not sure how long the battery does last (not as long as claimed) but rarely do I have to stop what I’m doing and connect the charger.

At one time I always had a fully charged spare battery to hand but Apple no longer allows users to swap batteries on their laptops or phones. 🙁 I keep an old laptop with a fully charged battery in case I have to go out and might need to use a computer.

As Duncan says, there are ways to maximise battery life. It is worth adjusting the display so that it is not brighter than it needs to be. Turn of Bluetooth and Wi-Fi if when they are not being used.

This comment was removed at the request of the user

I think my laptop is held together with Apple’s pentalobe screws, Duncan. That sort of screwdriver is not in my collection. 🙁 The battery has done 874 full charge cycles. My older laptop (late 2011 model) has done over 1600 cycles and still has 88% of the original capacity, even though Apple reckons the battery life as about 1000 cycles maximum. That one could be taken apart with a small Phillips screwdriver.

I have seen Apple batteries fail prematurely but I have been lucky so far.

Amazon sells an Apple repair kit of all the driver heads you need. A very old Laptop failed eventually, so I ordered a new battery and swapped the failed one. Very simple, and quick.

I agree, but it would be much simpler if the batteries could be replaced without tools. Of course it is not just Apple that denies users the opportunity to pop a fresh battery into their laptops and phones.

Oliver says:
19 April 2017

Manufacturers do not seem to want to supply replacement batteries for very long after a model is sold – they are probably items that they experience frequent warranty claims on and/or want to avoid the risk of manufacturing defects affecting entire batches resulting in an expensive recall and reputational damage.

Buying third party batteries is difficult. It seems in many cases they are channelled through small importers who re-badge them – selling on price with no great need to build up a reputation. Quality control may not be very good. Some manufacturers may be re-using old cells. Presumably there are also questions about how well the electronics and any firmware in the batteries is designed/programmed.

I often experience poor battery lifetime from third party replacement batteries and I wonder about the reasons and whether I can improve my buying choices.

One thing I often see advertised by third party battery suppliers is a claimed capacity a bit larger than the original batteries.

My suspicion is that to avoid short battery life, the electronics has to be programmed to keep part of the capacity unused. e.g. the battery will claim to be flat when it actually still contains some charge. The third parties may be tempted to reduce this spare capacity so they can quote an apparent improvement in battery capacity (which comes at the expense of a shortened lifetime – at least for anyone who drains the battery to a low level on a frequent basis). A similar effect may be achieved if the battery is set to charge to a higher voltage.

Also I wonder if there are other factors which may be causing reduced battery lifetime in older laptops. e.g. Laptop battery charging circuits may deteriorate? Power usage of a laptop may become more demanding as more applications are installed? Web pages become more intensive over time? More hardware is installed (e.g. memory)? User may change settings from default (e.g. in some laptops enabling a password check in BIOS when a laptop is resumed from sleep can prevent the sleep to hibernate transition which may be configured). I notice the rated power (on drive label) of hard drives and SSDs seems to increase with capacity. While a replacement SSD may use less power for a given amount of data throughput, the peak current drawn may be larger than the original drive. Would this age a battery faster than usual?

Apple devices seem to have very good battery reliability – what are they doing differently?