electric CBR600 PC25

Have the following problem: The babe has killed me within 2 weeks two batteries. Now it is so that it starts from time to time but after some time (up to 5 minutes) the backup of the start circle is shredded. As a result it is no longer possible to start (it is also logical). Sometimes ( with new backup ) it catches them directly at the start process. I already made some measurements but can not fetstellen. Oh you Honda Gods please help me !!