Pull the clocks/opimate fuse out from the fuse box , the place your amp meter probes into the connections where the fuse was pulled out. Have the meter set for the milliamp scale and have the probes in the current position ma jacks on the meter (red in ma , black to com , dial set to ma). Then read the current off the meter. Let us know what reading you are getting . MX said his was 19ma . Others have reported 11ma and 9 ma , I have less than 2 ma. Others like FE may have even less , his battery lasts a long time with no maintenance charger. I have gone two weeks without a charge and I can start my bike no issues. Some of these VDO's must be drawing more current than others. Once you get that information , find out which tacho or speedo is the worst offender .