One of our teammates crashed during a Contest, the radio did not respond at all, not even fail safe.

It was either the battery or the switch that failed most likely, any ideas or experiences? I have four Duralite batteries and it is not the first time I hear stories about this.

Any reasonable comment will be appreciated, please do misinterpret my question I don't want to harm the manufacturer, I just looking for a safe way to operate the product or go to other options if it is not safe.

Best regards to all