Manage your power: Our guide to powering your iOS and Mac devices

Anthony Caruana
10 January, 2014
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Power – it’s something we take for granted. Sure, we complain when the price of electricity continues its seemingly inexhaustible climb. But we know it’s going to be there when we flick the switch.

With our technology, it gets a little more complex. Many of our devices rely on power that’s ‘clean’ – at a fixed voltage, current and frequency. Others, like our iPhones, iPads and portable Macs become elegant paperweights when their batteries are out of juice.



Michael Thackeray, a senior scientist at the Argonne National Laboratory in the US recently summarised the challenge of battery technology.

“The periodic table has a certain number of elements, and you want to go light, and you want to get as much electrochemical potential out of these batteries, so the choice that you have in terms of the known elements is actually very, very small.”

The Mophie Juice Pack’s 1440 mAh battery can boost your iPhone’s longevity by 80 percent.

Most modern devices use Lithium-Ion cells to convert chemical energy into electrical energy. At the moment, this chemical combination offers the best balance between weight and energy output. According to Thackeray, there’s still room for improvement in this technology. Certainly, we see that in the most recent MacBook Air, which offers significantly more run time while CPU power is improved.

However, like all technologies, we will eventually hit the limits of what can be achieved. So, that means we will need to look at other ways to generate power. For example, we might need to look at liquid fuel systems. But these offer challenges – such as airline travel.

Christopher Johnson, from Argonne, describes how liquid batteries work.

“You would be able to store the charge in a liquid that you could pump through the battery and then, once it’s pumped through, you could recharge it by pumping it in the opposite direction.”

Closer to home, researchers at CSIRO have started developing the UltraBattery. Although this isn’t specifically a technology targeting portable electronic devices, it highlights the sorts of things that are possible.

UltraBatteries use super-capacitors – devices that store electrical energy – in combination with lead-acid batteries. In other words, combining robust and well- understood technologies, the researchers have been able to deliver greater power and lifespan in batteries.



Think about battery power like you think about your budget. Your finances have two main activities – income and spending. The same goes with battery power – you can either add energy (by recharging or buying new batteries) or use energy. To increase the amount of time you get from the available energy you can either use the energy more slowly or provide more input.

The evolution of existing battery technology delivers increased input, but you can do a few things to slow down the power drain.

With your iPad and iPhone, you can reduce your power use in a few ways. Disabling cellular communications, Bluetooth and Wi-Fi when you’re not using them can make a significant difference. There’s no need to turn them all off, but if you’re not using one then there’s no need to leave its radio operating. With cellular communications, disabling 4G can make a significant difference if you’re not in a coverage area.

And if you think that the power used by your iPhone is just a trickle of what you consume – consider this. Mark Mills, the CEO of the Digital Power Group, says that a medium-size refrigerator will use about 322 kWh a year. The average iPhone, according to Mills, uses about 361 kWh a year once the wireless connections, data usage and battery charging are tallied up. So, saving on power use can have a real impact on your hip pocket and the planet.

We’re going to focus on consumption and look at what equipment can help you manage your power more efficiently and what you can do to reduce the amount of energy you use.


Every office, large and small, uses several devices. There will be a main computer, a telephone, some storage appliances, networking gear and other equipment that’s essential for running your business. This goes for home offices as well as larger corporate workplaces.

Even though the Australian power system is designed to deliver 240 volts at a frequency of 50Hz, this can vary if there is some event on the power system. For example, if there is a localised blackout, or a car accident, a lightning strike or some other random event, those specifications can be breached.

When you’re dealing with power in the office, we’d suggest considering continuity (keeping the power running if there’s a short-term power outage), quality (managing fluctuations in voltage and frequency) and efficiency (using less power in order to reduce costs and your carbon footprint).


With continuity and quality, a decent Uninterruptible Power Supply, or UPS, is a good investment. These devices take the power from one of your power outlets and use it to charge a battery. Your equipment uses outlets on the UPS as their power supply.

The UPS has several power outlets that your equipment can then connect to. Rather than receiving power directly from the mains, they receive a filtered power feed as the UPS takes the inbound AC electricity, converts it to DC to charge the batteries
and then it is inverted back to AC from the batteries that power your equipment.

Eaton’s 3S 550VA UPS protects your equipment and gives you time to shut down your Mac in the event of a power failure.

When you’re buying a UPS, think about what devices you’d want to connect. For example, there’s little point using the battery to keep a set of powered speakers and a second screen running when the power goes out. If you’re worried about the quality of power going to those devices then we’d suggest getting a decent power board with surge suppression to protect them.

Some of the UPS devices we’ve used have a combination of battery-supported outlets and surge-protected outlets. If you choose one of these devices then make sure you connect the right devices to each outlet.

With your networking equipment, we’d strongly suggest not running these directly off mains power and using some form of power protection. If your budget doesn’t stretch to a UPS, a decent power board is important. In our experience, the power supply of many consumer-grade network devices is susceptible to failure after a power blackout as there can be a small surge when the power comes back on.


One of the rarely exploited technologies in many offices is Power over Ethernet, or PoE. The data cables that we use to move our information around can also be used to deliver electricity to some devices. For example, many VoIP phones and security cameras don’t need a separate power supply. They can get their juice straight from the network.

For this to work, you need a network switch that supports PoE. This will set you back a little more than a standard router – our research suggested that an eight-port Gigabit router that supports PoE will set you back around $200. Similar, non-PoE gear costs about half that amount.

 Netgear’s ProSafe GS110TP Smart Switch features eight PoE-capable Gigabit ports.

However, the benefit is that you don’t need to connect devices to power outlets on the wall. This will reduce the desktop clutter caused by having lots of power cables and reduce your electricity usage.


When you’re looking at managing the power in your office, we’d strongly suggest auditing your equipment and making decisions about which devices need to be on all the time, which can be shut down overnight and whether the gear you have offers reasonable power efficiency.

In some cases, devices that you’ve had running for several years – routers are a good example – have been superseded with newer models that not only offer faster networking performance but also use less power than older devices.

Similarly, printers have come a long way over the years in terms of their standby power consumption and the amount of energy they use when printing.


The myFC PowerTrekk requires only water to recharge an iOS device. The portable power pack turns H2O into hydrogen and oxygen. The hydrogen then generates power.

Sitting in an office, it’s easy to get complacent about electricity. After all, you’re only ever a short distance away from a power outlet that delivers a reliable energy supply.

But when you’re out and about, it’s a different story. The iPhone relies on a Lithium-Ion battery, while the MacBook range and iPad use a Lithium-Polymer technology.

Both types of batteries work in similar ways. The main difference is that Lithium-Polymer batteries are made with different materials that allow them to be packed into a wider variety of shapes. Apple has used this property to good effect when making their devices thinner as the batteries can be shaped to accommodate our thirst for thinner and lighter devices.

When it comes to battery care, there are lots of different pieces of conflicting advice. Some people say you have to let a battery fully discharge from time to time while others say you should run your devices from mains power as much as possible.

It’s clear to us that the point of a battery is so that the device can be used untethered from a power socket. Our advice is to not think about it too much. If it’s convenient to have your device plugged in, then leave it plugged in. If you’re on the go, rely on the battery. Over the years, we’ve used

many different portable Macs, iPads and iPhones. Our experience is that even after a couple of years that the battery life doesn’t change enough for us to notice and we don’t follow any special steps or procedures to maximise battery life.


Switching Wi-Fi and Bluetooth on or off is simple with Control Center in iOS 7.

When you’re away from the office, there are several steps you can take to ensure that your battery isn’t being drained any faster than it needs to be. The easiest place to start is wireless communications.

When you’re out do you really need Bluetooth switched on all the time? Even when disconnected, a wireless radio that is on will be looking around every now and then for devices to connect with. If you’re not planning to use Bluetooth – turn it off. The same goes with Wi-Fi. If you’re out with your iPhone and unlikely to be connecting to Wi-Fi for a few hours there’s little point having it switched on looking for networks you’re not going to use.

What about 4G? There is speculation that it can drain your iPhone or iPad battery faster than 3G. The truth is – it depends on what you’re doing.

When you’re in a 4G coverage area, the radio is more energy efficient than 3G as it spends less time downloading data. For example, electronics design company Synopsys did some research that found streaming a movie over 3G used more energy than streaming the same movie over 4G.

However, if you’re not in a 4G-coverage area – and that means most of the country outside major cities – then that 4G radio is constantly looking for 4G networks and therefore using more power.

If you’re outside a 4G-coverage area, you might find your iPhone or iPad gets a significant battery boost by disabling 4G.

Once you’ve dealt with communications, it’s time to look at apps. Although it’s handy to get an alert when an email arrives or someone comments on your lunch on Facebook, all those apps checking for new data and receiving alerts can chew through power.

Head into the Notification Center on you iOS device and look through the list of applications. Turn off notifications unless you absolutely need them for a specific app.

Also, look out for apps that use Location Services. For example, the Facebook app can use Location Services to tell people where you are. While that may be useful, the GPS receiver in the phone uses power.


When it comes to accessories for fuelling your digital devices on the go, there are two main product categories – battery packs and devices that either generate or supply power.

With battery packs, you need to get your head around how battery capacity is measured. Battery capacity is usually reported in milliamp hours (mAh). For example, the iPhone 5 has a battery capacity of 1440 mAh.

If you’re looking for a battery pack that will fully recharge your iPhone, then that device will need to have a capacity of at least 1440 mAh. Packs that offer more than that can deliver multiple charges to your iPhone.

There are many iPhone and iPad cases on the market that integrate a battery so that they extend the run time of your iPhone. So, even though they may not fully recharge your iPhone, they will significantly increase how long you can work between trips to a power source.

If you’re looking at buying a second power supply for your iOS gear, make sure that it’s well made and comes from a reputable source. A recent investigation by Apple into an iPhone that overheated was caused by a third-party power supply that was not up to the job. In response Apple launched a scheme where owners of third- party power supplies could return them to Apple and receive a discount on a genuine Apple accessory.

Twelve South’s PlugBug World charges a MacBook and an iOS device simultaneously from a single outlet and includes five different adapters. 


When it comes to getting power to your devices when all your battery supplies are exhausted and you’re nowhere near a power outlet, you need a power generator.

A Power Inverter can be used in the car. It connects to the lighter socket and inverts the DC feed from your car into an AC feed that can be used with your devices.

The amount of power an inverter can deliver is measured in watts. In order to calculate the number of watts you need to power your device you need to carry out a simple calculation.

Belkin’s Dual Car Charger with Lightning to USB Cable offers two USB 2.0 ports to charge your iOS devices while in the car.

By looking at the information or you computer, iPad or iPhone’s power supply, you can see how many amps and volts it uses. For example, an iPad charger requires 0.45 amps and 240 volts (actually, it will run at 110 volts but we’ll stick to the Australian power system). That gives you 108 watts.

The good news is that Apple’s power adaptors all provide the number of watts they need so you can avoid doing any maths. The power supply on our MacBook Air requires 45 watts and the iPad actually only needs 10 watts. That tells us that a 100-watt inverter would be adequate for charging our iPad, MacBook Air and iPhone while we’re driving.

If you’re camping then you might want to consider a solar charging solution. These consist of a set of photovoltaic cells that convert the sun’s light energy into electrical energy, a battery pack for storing that electricity and an inverter so the energy can be used by your gear.

Solar power requires decent access to sunlight. Our experience has been that you need to have your solar charger out in the sun for a while before it will charge your gear, although this might vary depending on the equipment you choose.



There are hundreds of different power accessories for your Mac or iOS hardware. Trying to create a definitive list is almost impossible, but the products we’ve looked at give you an idea of the range of different options around.

Kogan Universal 6600mAh Power Bank ($29) 

Kogan has several battery packs on offer, but this one demands attention as it has a massive capacity and it can deliver up to 2 amps of output – which is enough for larger devices as well as iPhones and iPads. It comes with a number of charging connectors, so it can be used with iOS devices with either the older 30-pin or newer Lightning connectors, as well USB- powered devices and some mobile phones.

Targus 100W Auto Power Inverter ($70)

With a standard power outlet as well as a USB port, Targus’ inverter is designed for in-car use. It’s shaped to fit into a cupholder so that you can reduce clutter while driving. Rated at 100W, it can deliver up to 150W for short periods although the rated capacity is plenty for most portable Macs or iOS devices.

Voltaic Converter Solar Backpack ($165) 

Who needs to carry more stuff? Not us. So, when you can make your bag into a charger, you can reduce the amount of gear in the bag. Voltaic’s Solar Backpack has a small array of solar panels on the back that allow you charge devices safely stowed inside padded sleeves within the bag. Voltaic says that six hours in the sun fully charges a typical phone and one hour provides about 75 minutes of talk time.

Mophie Juice Pack Helium ($80)

The Juice Pack can boost your iPhone’s battery life by 80 percent while only adding a few millimetres to the overall size of your iPhone. The case has an integrated 1440 mAh battery that complements the iPhone’s built in powerplant. It comes in a range of colours so that your iPhone will not only last longer but also score a facelift.

Kensington PowerBack Battery Case with Kickstand and Dock ($90)

Many of us love to use our iPads for watching movies while travelling as well as working. And there’s nothing worse than getting to the climax of a great
film only for the battery to run out of juice. Kensington’s Battery Case boasts a 4400mAh battery so you can get an extra five hours of run time and a kickstand that keeps your iPad propped up on a nice viewing angle.

Quirky PowerCurl ($13)

OK, so the PowerCurl isn’t going to save you money or boost your MacBook’s battery life but it will declutter your workspace. The PowerCurl clips on to your portable Mac’s power supply and lets you wrap the cable so that you don’t end up with a desk that looks like someone tipped a bowl of spaghetti over it. It also keeps the power supply off the desk, allowing better air circulation around it so that it doesn’t get as hot. An inexpensive, simple device that many travellers would love.

Eaton 3S 550VA UPS ($92)

With three surge-protection and three battery-powered outlets, the 3S protects your equipment and gives you time to shut down your Mac nicely in the event of a power failure. Rated to deliver 330W of power, that’s plenty for most current Macs, which use less than 200W – although older Macs are less power-efficient. For the price, the Eaton 3S will do the job in most small offices.


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