International

Apple has admitted it does intentionally 'smooth out' the performance of its smartphones when a battery gets too old.

A consumer watchdog that evaluates electronic gadgets' performance sparked an outcry after it found that processing power of older models is limited once battery life begins to suffer.

Many claimed it was an attempt to force users to upgrade to the latest model.

Today, Apple said the software update is actually prolonging the life of the phone and stopping it from shutting down as the batteries age and becomes less effective.

However, the firm has come under fire for not being more transparent about the software update, or explaining to users when it happens.

The shutdowns are caused when iPhones hit peaks of processor power that the battery was unable to power - causing them to simply shut down.

Apple said its software 'smoothed out' these peaks, allowing the phones to continue operating.