Ever since smartphones arrived, the most common way of recharging them has been to plug them in when you go to bed, then disconnect them in the morning with a full charge to last the day. This made a lot of sense when batteries took a long time to get up to full charge, as the eight hours in bed gave both the user and device time to recover from the previous day's exertions. But now, as the period it takes to charge a battery has dramatically reduced, it's time to reconsider how you top up the tank. iPhones use Lithium-ion batteries because, Apple states, they "charge faster, last longer, and have a higher power density for more battery life in a lighter package". These are all fine features, but one thing that Li-On is not really keen on is being reduced to 0 percent and then back up to 100 percent each day. Apple recommends, as do many others, that you try to keep an iPhone battery between 30 and 80 percent charged. Topping up to 100 percent isn't optimal, although it won't necessarily damage your battery, but letting it regularly run down to 0 percent can prematurely lead to a battery's demise. There is an exception, as it's considered good form to do a complete 0-100 percent charge about once a month, just to keep the battery in good shape. For all other instances, though, the best practice is to top your battery up periodically during the day so that it stays in that sweet spot. Hopefully, this should keep the cell healthy for as long as possible. To make this easier to achieve we recommend keeping an extra charger at work or in your car so that you can pop the iPhone on to it when you see the battery beginning to fade. There's more on why you shouldn't charge a phone overnight here.