What battery do I get to replace the battery behind the back cover?

From what I understand there are 2 batteries in the 5g. LS40 & LS30? Which one is behind the back cover?

Would the KV40 work for 5g? seems to be battery from 1st Razr.

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0