I know that many of us span multiple systems, so those of us who shoot Nikon should be aware of a battery recall...
http://www.nikonusa.com/en/service-and-support/service-advisories/h0ndzaip/EN-EL15-Rechargeable-Li-ion-Battery-Pack-Recall.html
http://www.nikonusa.com/en/service-and-support/service-advisories/h0ndzaip/EN-EL15-Rechargeable-Li-ion-Battery-Pack-Recall.html