I had 2, both alternator break-downs.
One was a Chrimbo evening job to the sorting office and back, the car starting acting up on the way there on a FN cash job, yer-man-o went in to the sorting office to collect his package, and then my cab would not start when he returned.
I told him to order another FN and requested no fare but he insisted on paying me a Tenner in cash, the traffic was manic that evening but he got a taxi 8 minutes away and showed me his phone cos I reckoned on seeing the bad traffic the driver would cancel. I recognised the driver Ahmed who was an old base colleague of mine and rang him telling him not to cancel and explaining the situation, Ahmed arrived 15 minutes later so at least the customer was looked after.
Thankfully I had breakdown rescue (€50) on my AXA insurance policy and even given the bad traffic they were there within 40 minutes and lifted the car and brought me and car to my mechanics yard.