Weird iPad mini charging problem

Hmm. Today a Year 6 teacher told me that the iPads weren’t charging. The ISIS charging cabinet is basically some 10 and 8-way power adapters plugged together with iPad power adapters plugged in. But yet it seemed that all the iPad power adaptors didn’t work that were plugged into one of the 10-way power bars. I checked with a different adaptor, and the 10-way adaptor was definitely still working. I then took out the iPad charger and plugged it directly into a wall socket. That seemed to make it work again! I had to do that with all the iPad adaptors affected, but they now seem to work ok.

This is a little bit worrying. It could be an issue with the iPad mini design, with the lightening cables or with the fact I’m using lots of power bars. I’ll keep an eye on it. It’s worked fine up until now though, which is what is particularly confusing. Maybe there was a power surge which affected the iPad power adaptors?