Oh man, I had my battery die and yeah, you can tell because it won't save your midi channel names and such. I replaced the battery, but it was probably the hardest thing I had to do on my 60, because you gotta remove the system board, and that had me sweating bullets, and removing the battery is no joke because it is soldered in, and if you over heat it it can explode!! leaking acid everywhere causing more problems.
A tech should be able to fix it for about $50-$80, maybe cheaper depending on where you go, but I would say get it fixed when you can, and have them put in a battery holder so next time you just pop a new one in from radio shack, that's what I did. They last about 10-15 years. I guess you could do without it, but it is nice to have that battery up remembering your little settings and such.