I would say new battery time

[jScotD]

Though it's only a little over a year old.

I did a search here and found if your battery wasn't keeping a charge to charge it off the machine and then see what happens.. It went from 13.9, having charged all night, to 12.8 in 5 hrs.

Charged it again and it went from 13.9 to 13.2 while I watched the voltmeter.. now 3 hrs later ...12.9..

hmm.. decisions, decisions.. which battery should I buy? I'm a little leery of replacing it with the same one that came from the factory.. hmmm.. gotta ponder this one

 

[ARtraveler]

I am still running my original battery in the 2010 RT-S. It goes on a Battery Tender Jr. once I park it for the winter. If I don't trade it off, it will be a new battery for the 2010 next season--just because.

 

[nhoj]

... It went from 13.9, having charged all night, to 12.8 in 5 hrs.
Charged it again and it went from 13.9 to 13.2 while I watched the voltmeter.. now 3 hrs later ...12.9..

Yuasa states the minimum Terminal Voltage for a fully charged battery is 12.6V after 1 hour or more following full charge. Ours generally indicate 12.6-12.8V the day after. I recharge them when the Terminal Voltage drops below 12.4V. Inside storage in the winter. Never have to charge or maintain them during the riding season. When I sold my V-Strom it had 5 seasons on the battery and I had only charged it over the winter(s).

Unless your batter fails a load test it sounds normal.

John

 

[NancysToy]

A battery should always read considerably higher fresh off the charger. As long as it remains at 12.7 or above the next morning, it is probably good. Your numbers are excellent. If you are having problems, they probably lie elsewhere.

 

[jScotD]

hmmmm.. why should the battery drop voltage if it's not hooked up.. and so quickly.. sitting on the bench..... mine won't start with a 12.2 rating.. goes through the buzzing and the flashing of the screen.. then stares at me and says sure charge me again and in the a.m...

 

[Chupaca]

Seems to me..!!

your battery is good. You can load test it to make sure. One year old batteries under normal use rarely go bad. Surface charges are a bit higher and dissapate rather quickly leaving the actual full charge. If you are not getting good ground contact and a good starter cable connection you will have troubles starting your machine....hope thats all it is, I like Yuasa it's kept all my electric start machines going 5 years ir more... :thumbup:

 

[NancysToy]

hmmmm.. why should the battery drop voltage if it's not hooked up.. and so quickly.. sitting on the bench..... mine won't start with a 12.2 rating.. goes through the buzzing and the flashing of the screen.. then stares at me and says sure charge me again and in the a.m...

12.2 is far too low, and indicates a bad battery if it drops that low when disconnected. Batteries show a high, superficial voltage immediately after charging, close to the charging voltage. They taper off and level out quickly, however. The reason for checking the next day (or after several hours) is to see if they will hold a charge (or if there is a parasitic load pulling them down when connected). A battery that has rested several hours should read 12.6-12.7 or higher if it is good and is not being pulled down excessively. Below 12.6 volts the Spyder will be unhappy.

 

[jwulf74]

I had a battery in the GTO that was less than a year old. It acted like the original post. It would start the car a couple of times and then need a charger. I charged it several times and eventually disconnected it from the car and checked it that way to see if there was a parasitic draw. It would still drop voltage. I had it tested where I bought it and they said it was good and would not warranty it.

I could not trust it to start the car anymore though. I put in a different one and never had a problem after that.

Moral of my story...if you don't trust the battery to not leave you stranded somewhere, forget about any test results. Put a new on in that you can trust.