BMW R1200RT/R1250RT Forum

Tony Fyson wrote:There are several threads on replacement batteries. Can you recommend a suitable replacement.

This battery is suitable for Wethead 1200's and Shifthead 1250's,
AGM12-16 EXIDE MOTORCYCLE BATTERY 12V 16AH 170A 4920 | AGM Batteries | Batteries & Power Electronics | Battery Group

This is the Tayna list of compatible batteries, YTX16-BS Compatible Motorcycle Batteries (tayna.co.uk)

David. wrote: This battery is suitable for Wethead 1200's and Shifthead 1250's,
AGM12-16 EXIDE MOTORCYCLE BATTERY 12V 16AH 170A 4920 | AGM Batteries | Batteries & Power Electronics | Battery Group

Funnily that's the same battery ive just fitted to my 2007. It was a direct fit

This is the OEM battery for a Hexhead (2007) or Camhead (2012). Tayna offer this selection, 51913 Motorcycle Batteries (tayna.co.uk)

This is the OEM battery for a Wethead (1200) or Shifthead (1250).

This doesn't add much to the discussion but wanted to chime in anyway....
This past summer I was touring the Rockie Mountains and my OEM battery decided to give up after a cold night.  Came out in the morning and nothing when I hit the starter, not even a solenoid click.  I finally got a jump (gee thanks AMA, for no help).  The nearest battery was a Yamaha dealer 120 miles away.  It was a bit tense as I had to ride the bike over a mountain pass with little traffic and no services close.  I was not sure if the engine stopped for any reason that it would restart.  Can you even bump start these bikes anymore?
Long story short, I got to the Yammie dealer to find out the battery was a yuasa wet cell.  They had to put acid in and charge it before I could install it.  I did the install since they would have charged me at least an hours labor at pretty high rate.  That was fine as I did the swap in about 15 minutes and the RT started right up and has been doing fine since. 
I'm torn as to whether I should replace the yuasa, or just leave it in as it's been starting and charging fine.  With snow on the ground here, I'm unable to ride for a week or more at a time and keep the battery on a tender and it's been fine.  I now carry a jump starter with me all the time as I'm not confident the bike won't strand me again.

Grumpy wrote:I'm torn as to whether I should replace the Yuasa, or just leave it in as it's been starting and charging fine.

Yuasa batteries are usually pretty reliable. One drawback with a wet flooded battery is obviously checking the electrolyte level. Plus, where is the breather pipe routed to on a bike which would normally have a gel sealed battery. Then, there is the risk of spillage/leakage of battery acid.

I've got a Yuasa wet flooded battery on my Yamaha Xj650. The next new one is likely to be an AGM version.