It is very common for us to spend hours working with our MacBook connected to power, especially when we regularly use it at a desk. In this situation, there is a setting that allows us to set a maximum charge limit so that the battery spends much less time fully charged. The iPhone has offered a similar option for some time, but it is on the Mac, which we tend to keep plugged in for many more hours, where its effect can be even more useful.
What changes when we limit our MacBook’s charge
Lithium-ion batteries age over time and through charge cycles. It is an inherent part of how they work and of the chemistry that makes them possible. Spending many hours at very high charge levels considerably accelerates this chemical ageing. For this reason, keeping our MacBook at around 80 or 90% significantly reduces the stress on the battery and helps it preserve its capacity better over the years.
There is one important distinction, however. The battery charge limit works differently from Optimized Battery Charging. Optimized Battery Charging learns our habits and decides when it makes sense to temporarily keep the charge at around 80% before completing it, predicting when we are likely to unplug our device from power. The charge limit, on the other hand, allows us to set a maximum level that the MacBook can reach when charging its battery.
We can check battery health and charge cycles directly from macOS to keep track of how they evolve, and we can try the many supposedly miraculous tricks found online to reduce battery wear. In the meantime, limiting the battery’s maximum charge is currently the best way to reduce its ageing in a genuinely effective way.
How to set a charge limit on our Mac
Setting a charge limit is exceptionally simple. In just a couple of seconds, we will have our Mac configured with the right setting and in a much better position to handle being connected to power for long periods. We do it like this:
- Click the Apple menu and open System Settings.
- Go to Battery.
- Click the information button next to Charging.
- Move Charge Limit to 80%, 85%, 90% or 95%, then click OK.
Even with this setting enabled, our Mac may occasionally perform a full charge to keep its battery level estimates accurate. During normal use, however, the system will respect the percentage we have chosen.
What percentage should we choose?
For a MacBook that spends almost the entire working day on a desk, an 80% limit gives us the greatest margin for looking after the battery. If we alternate between working at our desk, attending meetings and travelling, we may need to move up to 85 or 90%. The best approach here is to start with the lowest figure that makes sense for us and, if necessary, increase it gradually until we find the right balance between battery care and battery life.
When we need every possible minute of work away from a power outlet, we can use Low Power Mode on the Mac. Without changing the charge limit, it will help us squeeze as much battery life as possible out of our MacBook.
At Hanaringo, we specialise in Apple and offer personalised training and technical support for individuals and businesses, tailored to each person’s needs. During our sessions, carried out by phone and with remote screen access whenever necessary, we cover initial setup, iOS, iCloud, Photos, storage, accounts, social media, security, privacy and complete technical support. And yes, we very often talk about how to take care of the batteries in our devices.
This may seem like a small setting, but it can make a very significant difference after several years of use. Apple allows us to adapt charging to our habits and, for those of us who use our MacBook connected to power for a large part of the day, this is an option we will notice. A lot.
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