charging prob or bad battery?

Some of you guys know of the 98 I just bought. It has the battery from my 4 wheeler in it, which is the exact model the bike calls for, and is only about 7 months old. It's a Yuasa purchased at my dealer just last year.
Here lately I have been noticing this bike turning over slower and slower. Well, today it failed to start and killed the battery. I had just done the voltage tests on the R/R....about 13.4V at idle, and about 14.7 at 5000 RPM. Those are good numbers, so why is my battery getting so weak? Is it possible something else is draining it, or is this battery just faulty??

 

Must be a bad battery cuz the charging is fine.

 

Check for bad connections. Sometimes your charging system is good, your battery is good and the connections are bad. Best way to test the battery is to pull it from the bike, fully charge it, let it sit for 2 hours then test the voltage. Good battery fully charged is about 12.7v to 13.1 v. Anything under 12v battery is gone.

Check out Yuasa Technical Manual at Yuasa Batteries It will tell you everything you ever wanted to know about batteries.

 

Like was said you may have a bad connection somewhere or something is draining the battrry as it sits? Before i fixed my r/r and it was killing my battery the battery itself checked out fine with my multi-meter at around 12.8 or so and i couldnt understand why it wouldnt crank. But after having it tested the cold cranking amps were so low it wouldnt even try to start. It seems your chRging system is fine but i would have that battery tested first just to rule that out. Did the battery sit for extended times in the four wheeler before you put it in your vfr? If the battery checks out then i would look over all your wiring for any possible drains on the battery. Good luck

 

No the battery has not sat for extended periods without at least me starting that 4 wheeler every once in a while.
But now I wonder if something is up with that 4 wheeler.....this is the 2nd battery I've bought for the thing in a year and a half.....that's pretty suspicious and I just remembered that. I'm thinking perhaps the 4 wheeler has already damaged this battery somehow and now it's a little weak. It's a Honda Recon,
hell they probably have faulty R/R's too I suppose!!

 

Thats funny. May want to check into those recons to then.

 

And I don't think it's a connection because after 10 minutes on the charger, it fired right up no problem.

 

It was the battery. They tested it and it was only providing like 60% capacity. it was still under warranty so they gave me a brand new one, fresh off the charger. I put it in and WOW....the difference is amazing. That other one was really struggling to get my bike running and I didn't realize how badly until now.