GM to modify its electric Volt to help prevent battery fires

General Motors says it will modify all of its Volt models. The announcement comes after federal side-crash tests resulted in three battery fires.

The fires occurred up to three weeks after the tests when coolant leaked into the cars' batteries.

There has been no recall of  GM’s electric Volt, but the automaker is voluntarily asking owners to bring their cars in for a fix.

"We've added some structure that allows the load to be spread, so it doesn't cause intrusion into the battery pack or coolant leak," says Mary Barra,  GM’s senior vice president of Global Product Development.

GM sold about 8,000 Volts in the U.S. over the past two years. No fires have been reported by customers.

Volt owners will be notified when dealers get the repair parts – probably in February. GM says the modification should not take more than a day and a loaner car will be provided.