After shelling out what I consider a lot of cash for a battery tender, it lasted a little over three years. I have Deltran tenders that are working after ten years plus.
I called BMW, and I will say they were polite, but they told me that after the two year parts warranty is passed, you are s*&t out of luck. I am extremely disappointed. I have been a good OEM after market customer. I even bought a new BMW battery the other day (before the dealer told me that the tender was bad).
After paying mega bucks for clothes and pieces, you'd think they would at least do something....
I guess I'll just go the traditional tender wired straight to battery. I'm not paying the cash for unit that doesn't hold up. I must not be the exception, because I have looked on Ebay and seen some for sale as "no longer works. For parts only."
I may write the head of BMW Motorrad USA to let him know how I feel. Probably a waste of time. After being such a fan, and a Harley convert for over six years, this plain stinks.
Please let me know if I need to use a CAN BUS tender and should not use a regular one that is straight wired. The OEM looks cool, but I want one that lasts!