Source the right battery

Batteries aren’t supplied, and it’s crucial you use the correct ones. The Pi-UpTimeUPS uses 18650 non-protected batteries. There’s room for two, but you can get by with just one. Recommended capacities are 2,000-3,500mAh per battery. In return, the UPS can deliver both 5V power via a micro USB port (using pin 2) and 3.3V (700mA) of power via the Pi-UpTimeUPS itself.

In contrast, the PiZ-UpTime uses just a single 14,500 Li-ion battery – capacity 700mAh to 2,000mAh. Don’t be fooled by their appearance – they may look like regular AA batteries but they’re not, so don’t be tempted to use standard batteries. Both types are available from a range of sources, including eBay, Amazon and Maplin. Remember, the higher the capacity, the longer your Pi (and any connected add-ons) will be able to run on battery power – we got well over an hour out of an 800mAh Xtar-branded battery that we purchased on eBay (£9 for two).

It’s worth noting that the unit will perform a hard shutdown when the battery’s capacity runs dangerously low, thus prioritising the battery’s health over a few extra seconds of power.