As I mentioned, I had problems keeping a charge with my Yuasa. This was due mainly to my short daily commute. This resulted in very little charging time and 2-3 starts per day. When my second battery failed I did some research on batteries. I learned that lead acid batteries don't like going under 80% charge (a deep cycle) and they will only deep cycle a few times (3-5) before they start losing capacity to hold a charge.
My previous bike didn't go through batteries as rapidly despite the same routine. I discovered that the Triumph R/R is not as powerful/efficient as it could be and, more importantly, the charge cable from the R/R to the battery is undersize.
My remedies are detailed in
this post. In brief in order of effectiveness:
1. Upgrade (heavier) and shorten the cable from the R/R direct to the battery. A cheap fix.
2. Use a good quality trickle charger if your bike doesn't run regularly or only runs for short trips.
3. Check and upgrade your connections - battery, also to and from the R/R.
4. Get a Shorai LiFePo (lithium iron potassium) battery. Deep cycles many times more than lead acid. Tolerates dropping to 50% charge. Carries a bigger charge for longer. Much more powerful, smaller and lighter. Lead acid batteries are old technology.
5. Replace your R/R with a mosfet (superconductor) R/R from an R1 Honda.
6. Fit an onboard voltmeter to monitor your charging/battery status.
7. Fit a bypass switch for the ECM low voltage cut out. This enables you to start the bike with less than 11.6volts. Only recommended for emergency use because damage to the ECM could result with low voltage.
You probably only need to do the first 2-3 easy fixes. The rest is if you are really enthusiastic (read obsessive) like me.
