Canon EOS-1D X Mark II DSLR Camera (Body Only) - Manual (Page 542)

542
USA and Canada only:
The Lithium ion/polymer battery that powers the product is
recyclable. Please call 1-800-8-BATTERY for information on
how to recycle this battery.
For CA, USA only
Included lithium battery contains Perchlorate Material – special handling may apply.
See www.dtsc.ca.gov/hazardouswaste/perchlorate/ for details.
CAUTION
RISK OF EXPLOSION IF BATTERY IS REPLACED BY AN INCORRECT TYPE.
DISPOSE OF USED BATTERIES ACCORDING TO LOCAL REGULATION.