National Instruments PXI-8221 User Manual page 57

Appendix A Specifications
Battery Replacement and Disposal
This device contains a long-life coin cell battery. If you need to replace
it, use the Return Material Authorization (RMA) process or contact an
authorized National Instruments service representative.
After replacement, recycle the old battery. For additional information, visit
.
ni.com/environment
© National Instruments Corporation A-5 NI PXI-8183 User Manual