Fast-draining batteries are the quickest way to spoil festive fun as we're using our mobile devices for entertainment, gaming, social media and more. Until phone, tablet and other batteries are able to endure an entire day's heavy use, power banks are necessary gadgets to have around. Small and typically pretty cheap, they also make excellent gifts.

As with all consumer tech you'll find yourself paying over the odds for the top brands or fancy features. Hence we've put together our pick of the very best power bank deals available, as well as some handy buying advice tips.

Keep your eyes peeled for Amazon Lightning deals on power banks.

Best Power Bank Deals

Power Bank Buying Advice

All power banks have the same primary function: to charge other devices over USB. However, you'll find a variety of designs, some with multiple USB outputs and others that include Lightning or USB-C as well as the standard USB-A and Micro-USB ports. These days you can also find power banks that charge wirelessly, recharge themselves using solar power, and have power outputs high enough for a laptop or games console.

The number and type of inputs and outputs, whether or not there's an LCD screen, and extra features such as waterproofing and passthrough charging are all down to the user. The two things you really need to watch out for are capacity and power output.

Unless otherwise specified most power banks will run at around 65% efficiency, which means only 65% of whatever is their rated capacity will be available to charge your device. So if you're looking to fully charge a 3,000mAh phone you need a 4,615mAh power bank (3000/65x100). If you want to charge it twice you need a 9,230mAh power bank.

If you want a pocketable power bank it really needs to be no higher in capacity than 10,000mAh. Around 15,000mAh is good for throwing in a bag, while anything over this is a proper chunk but good for several days' life away from mains power.

For a phone or tablet almost any power bank will suffice. Avoid slow 5W (5V/1A) outputs like the plague, especially for tablets which typically have higher-capacity batteries and take longer to charge, but 10W (5V/2A) and 12W (5V/2.4A) connections are now pretty common. Many power banks support Quick Charge, which is faster still, but useful only if your mobile device also supports the standard. If it does not it will still charge, but no faster than usual.

If you're looking to charge a laptop or the Nintendo Switch, know that these require more power than is provided by a standard USB connection. This can be delivered by power banks that support power delivery, which is anything up to 100W. The exact charge you need depends on your individual device - the information is not always easily available, but a good rule of thumb is to check the spec printed on the charger it was supplied with.

If you're charging a Nintendo Switch, ensure you are using a cable with a 56 OHM resistor or you risk bricking your console. The cable supplied with the Nintendo Switch will do the job.

When is Black Friday 2020 - should you wait for a better deal?

Black Friday will take place on Friday 27 November, immediately followed by Cyber Monday on 30 November. Traditionally the biggest sales event of the year, it may yet throw up some even greater tech deals - but with so much uncertainty around finance and retail, and no guarantees regarding what discounts we will see, we advise you not to wait: if you see a deal you like, on a product you need, and you can afford the outlay, buy it today.

Read next: Best power banks and Best laptop power banks