"PS. I wouldn’t call batteryuniversity the total expert on battery operation and design, either. Since my friend’s occupation is testing and designing batteries, I will take his advice over any publication, where the authors are not known to me.
But… You may have a different opinion."
On the bottom of the page it says
" About the Author
Isidor Buchmann is the founder and CEO of Cadex Electronics Inc., in Vancouver BC. Mr. Buchmann has a background in radio communications and has studied the behavior of rechargeable batteries in practical, everyday applications for two decades. Award winning author of many articles and books on batteries, Mr. Buchmann has delivered technical papers around the world.
Cadex Electronics is a manufacturer of advanced battery chargers, battery analyzers and PC software. For product information please visit www.cadex.com."
Does you friend have 20+ years experience in the rechargeable battery field?