I use 4 rechargeable eneloop AA batteries for virtually all my arduino projects. I must have a dozen battery holders, some for 2, some for 3, some for 4 batteries and they ALL hold the batteries too tight, so that the spring at the -ve end of the battery can't move the battery forward so that the +ve end makes contact with the terminal. (Standard duracell AA batteries must be a tiny bit smaller, so those work fine) . So changing the batteries is always a real pain - having to shuffle the batteries back and forth, and checking with a multimeter that voltage is being supplied.
Are there any makes of battery holder that work with rechargeable AA batteries that don't have this problem?