With a plug for your BMW (article 90013)
Without plug, but with a cable and clips which you can connect directly to your battery in order to charge it without disconnecting (article 208-037-1)
Diagnoses, recovers, charges, checks and maintains your battery automatically for months. All major battery manufacturers recommend maintaining starter batteries FULLY CHARGED during periods of non-use. Optimate 4 is totally safe for months-long connection and maintenance of irregularly or seasonally used batteries even while still connected to the vehicle. The sophisticated charging algorithm ensures no risk of over-charging. For 12 volt batteries up to 32 amp-hours.