On Saturday morning I set about testing the Genius G-Note 5000, a hand writing tablet.

I inserted the four bundled AAA batteries into the back of the unit, flipped it over and before I got a chance to turn it in there was a very loud pop, followed by a fizzing noise.

At first I thought something else in the unit had exploded, but when I opened the battery department I noticed battery fluid everywhere and one of the AAA batteries had split apart at the seams.

The offender, a Maxell Alkaline Ace, got battery acid everywhere and I promptly wrapped the whole unit in a plastic bag.

Upon closer inspection (which stupidly involved me getting more acid on my fingers) I realised I'd put one of the other batteries in the wrong way round – a mistake made easier because the positive end has a spring on it just like the negative end. Either way, you wouldn't expect a battery to explode.

A quick call around my office revealed another Genious supplied battery did a similar thing about a year ago. Back then it was a GP 700 rechargable battery that was the offender. During its first battery charge it didn't go bang but did fizz and leak.

A Genious spokesperson blamed the incident on a faulty battery and said Genious has never heard of a similar incident.