How long should I expect the battery in my '02 R* to last? It was new August 2016 and I always put it on the battery tender. I do not remember what brand it is but it was not a cheap one. Temps have been around 45F here for last couple of days but bike would not crank over. I put it on a charger for a day and still would not crank. Battery voltage dropped to 8.5 while trying to crank. I boosted it and it started. Voltage while running at idle is 13.5v. If I need a new battery, so be it but it should last longer than 18 months.... My old Vstar 1100 was a basket case with a very much dead battery when I bought it. Put that battery on the tender and it lasted another 3 years in the bike before I bought the R*.

put it on a charger and charge it at least 2 amps even go to 6 amps or so for about 8 hrs. A battery maintainer charger will not charge a dead or depleted battery it will only maintain the charge on a good charged battery. A battery should be charged to get an accurate test to determine if it is Good/Bad As far as how long they last will depend on the battery brand. My OEM Yuasa lasted over 7 yrs before I changed it and it was still starting the bike just fine. I have seen members buy cheaper online batteries that only lasted a year and others that lasted 5 years. also to check the voltage with the bike running you should rev the bike to about 2500 rpm to see what the voltage is and it should be charging in the mid 14's volt range. After you have it fully charged if it drops to 8.5 volts when cranking the bike over the battery is junk.

I know it was a fluke but I had a battery go 8 years in my Intruder before it croaked. Here's to hoping this one lasts half as long.

I replace my Yuasas every 5 years or so because it seems like I should,
but my old pile still all tests good.

Used in bikes and sleds, so both seasonal and both with big temperature swings.

After I get 5 years, I'm thinking I have about $18 a year in it,
and I think of the ordeal of being stuck on the bike, or 100 miles from the trailer in 10 degree weather on a sled,
and I "splurge" on a new one.