The operator has tapped into the modern problem of customers streaming media, texting and browsing on their devices all day long, at a cost to battery life.
The Power Bars will be available to all EE customers with a 30-day, 12, 18 or 24-month plan. Pay-as-you-go customers who have been with the operator for at least three months will also qualify. Each Power Bar can supply one full smartphone charge.
EE currently ranks bottom of Ofcom’s customer service charts for mobile operators, with a satisfaction rating of 69%, behind O2, Virgin, Vodafone and Three.
The idea behind the new scheme is to reward customers and provide "never ending power". EE has set itself the target of becoming the number one operator for service.
Pippa Dunn, EE’s CMO, said: "Almost everyone’s experienced the frustration associated with running out of battery and it always seems to happen when you need your phone the most.
"With EE Power, we’re trying to help by giving our customers a Power Bar that can simply be swapped for a fully charged one at any of our stores, at any time, for free."
To receive a bar, customers must get a promotion code by texting "POWER" to 365. Each text will cost 35p.
The code can be exchanged for a charger at any EE store in the UK.