I'm guessing any of the 3 Yuasa would be a good choice. As well as many other brand name batteries like Deka or Duracell or even Delco. I tried one of those el cheepos in another bike once and it did not last very long at all. So not interested in a 40 dollar battery. This OEM on my 15 is still strong but surely it will need to be replaced soon. I do not use a tender but ride it often.