During the past few months I've had customers bring in batteries for testing, saying that although only a few months old they are failing before the end of a round.

On several occasions, and when taking the battery out of it's carry bag, the batterys were found to be quite old - and not the battery originally purchased by the customer.

This would indicate the customers battery had been mistakenly switched (or perhaps otherwise).

To safeguard against this, it is a good practice to indelibly mark the outside casing of your battery with your name or some other means of identification. Your trolley and other golf valuables should also be treated in the same way - its better to be safe than sorry.