Voltage and dying battery

[Val]

Hello, long time no see


I am having trouble with battery lately. After I charge it with charger and drive motorcycle for a while it has some trouble starting (I can see it almost does not start up, and if I try to start it few times in a row it can't do it after second or third time.


So my guesses were - faulty battery, faulty electric installation (shorted) or something with charging. So it did test:


- battery after charging with external charger and leaving for a while - 12.6V
- while starting motorcycle from fully charged battery - voltage drops for a while to about 9V (and when I do it second and third time it drops to about 7V)
- when idling and everything turned off - 14.4V
- with lights on and idling - 13 V
- with high beam and idling - 12 V and dropping


So what are your guesses - are voltages are OK on idle? I thought it always would be 14.4 even with lights (because voltage regulator should turn it up?)


Thanks!

It drops too much on start you need new battery, here is what manufacturer recomends if below 9.5V on start to change it:

http://www.yuasabatteries.com/faqs.php?action=1&id=30

You can do load test yourself like this:

Load Test

• Adjust voltmeter to DC volts (20 volt range).
  
• Place voltmeter leads to the battery terminals. (positive to positive and negative to negative)
  
• Watch the voltmeter as you start your motorcycle. Keep the starter pressed at least 5-10 seconds
  
• If the voltage drops below 9.5 volts during that 10 seconds, the battery has very low capacity and should be replaced.
  

A healthy 12 volt motorcycle battery should maintain a range from 9.5 - 10.5 volts under the load for a good 30 seconds straight.