diff --git a/ontology/saref4wear.ttl b/ontology/saref4wear.ttl
index 52459e4f9d0658981f84b68262e9bdb68d824648..1d052f1897ed5573633251a5b5e7ee976a345ce0 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 ;