diff --git a/ontology/saref4wear.ttl b/ontology/saref4wear.ttl
index 4e5364a750ca1b5c933272000c5358ee6afdafc9..ea7255d8db543d4b65c3bb6f0bb33c4dbbe63bfa 100644
--- a/ontology/saref4wear.ttl
+++ b/ontology/saref4wear.ttl
@@ -343,6 +343,12 @@ s4wear:followsPolicies rdf:type owl:DatatypeProperty ;
                        rdfs:range xsd:anyURI .
 
 
+###  https://saref.etsi.org/saref4wear/hasBatteryLife
+s4wear:hasBatteryLife rdf:type owl:DatatypeProperty ;
+                      rdfs:domain s4wear:Wearable ;
+                      rdfs:range xsd:double .
+
+
 ###  https://saref.etsi.org/saref4wear/hasCapacity
 s4wear:hasCapacity rdf:type owl:DatatypeProperty ;
                    rdfs:domain s4city:Facility ,