In case you didn't know, by deep cycling, soeren means being discharged a lot, then charged again. Like rechargeable AA batteries you would buy at wall mart. You use them until they are "dead", then you charge them. Automotive and bike batteries are constantly charged by the alternator (at least I think bikes have alternators), so without that constant charge, they'd die rather quickly. (Well quickly is a relative term, but you get the idea).