The equipment was reliable, its just that the batteries chose that moment to run out of electrons. Didn't expect anything like that so didn't put fresh batteries in before setting out. Now I know what to expect (if lucky) I will set out earlier to be in the right place at the right time and make sure the batteries are fresh.
I think, considering that without them the camera becomes nothing but an expensive fashion accessory, that's a given, however, they only hold so many electrons and mine always tend to chose a situation where lighting is critical and changing rapidly to run out. That camera gave the low battery warning when there was only enough power left for one or two shots, my current camera gives low battery warning with up to fifty shots left so you get plenty of warning or have enough power left to get the shot - a big improvement.