For those that want some extreme battery performance without the size and cost of a Mastervolt MLI, British company Roamer have launched the XTREME range. Designed by a British electrical engineer, this range of lithium LiFePO4 batteries are intended for off-grid use in temperatures ranging from -30°C to +60°C. LiFePO4 batteries are known for their ability to delivery continuous high power, but the XTREME goes further.

Its high-power cells allow for a full charge or discharge in just 30 minutes, meaning that even the smallest 100XTREME model, weighing just 11kg, which has a maximum discharge rate of 200A, can deliver up to 2500W of continuous power. That’s enough to power a kettle or an induction hob. In terms of capacity, it is claimed to still have enough juice to charge an iPhone 206 times or a laptop 51 times, cook nine pizzas in an air fryer or make 78 espressos from a coffee machine. For those that need more, there is the 200Ah 200XTREME, and a 24V 24-100 XTREME. Cost from £900 for the 100XTREME.  

The 100XTREME, fitted with carry strap and weighing 11kg, is realistically portable.