Custom Battery Packs Designed and Assembled in UK by Specialists PMBL. PMBL, based in the UK, is a Custom Battery Pack Design, Manufacture and Assembly company that has partnered with many businesses and delivered the optimum Battery Pack Design solution for each of their individual, bespoke business or product requirements. As a technology and design oriented, customer centric, battery pack manufacturer, PMBL are focused in their ability to provide the complete battery technology design, procurement and manufacturing process for a wide range of batteries including ATEX intrinsically safe applications.