Added hasBatteryLife datatype property. Issue #26.

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 ,