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I have been having problems starting my K12. After spending a lot of cash replacing 2 radiators I was told my battery was dead also. It was fine for the first couple of days then after a break for about 4 days I went to go for a ride and low and behold - flat battery. I put it down to possibly leaving the parking light on with the key in the wrong position, but after jump starting it and a ride of 3 hours I found that it still wouldn't start from the button. I took the battery back to the garage and they tested it put it on charge and said after 2 days it was slowly discharging at 10.54 volts. I was under the impression that a new battery ought to be pushing out 12v? Anyway I've been reading other posts and some issues over starter relays I may now have a further problem when I put the (second eventually replaced by the garage) new battery on today, or whether something on my bike may have caused damage to the battery and if that's the case I will probably be in the same position in a week or so.

I can do mechanics ok, but the electrics/ electronics and I am not certain when or how to read volts/ amps etc and what it means.

Any advice for battery voltage? Any for possible starter relay damage?
 

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So before you go chasing anything else ( Kiss) keep it simple sam, get a good battery in the bike first. Voltage should be 12.-13V never 10.5V

Sounds like the relay is Ok right now since if it had failed the starter would stay engaged, and seems like that didn't happen.
 

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Fatto said:
...I was told my battery was dead also. It was fine for the first couple of days then after a break for about 4 days I went to go for a ride and low and behold - flat battery. ...I took the battery back to the garage and they tested it put it on charge and said after 2 days it was slowly discharging at 10.54 volts. I was under the impression that a new battery ought to be pushing out 12v?
Your battery probably has a 'dead' cell.

A 12V battery has (6) cells of about 2.1V each, for a total of 12.6V. If one cell is dead, you will measure (12.6 - 2.1) or 10.5V.
 

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Sounds like a bad battery. Also, check the positive/negative battery connections at both ends. Bad connections will affect charging. When the bike is running it the alternator providing the correct output?
 

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The proper voltage for a fully charged battery is 12.8 volts. Technically when a battery falls below 12 volts it is discharged. At 10 volts it is dead. When charging the alternator should put out about 13.8 to 14.8 volts. Final charge voltage also depends on the battery type as a flooded lead acid and AGM, Gel cells all use slightly different voltages. Look in the Hall of Wisdom for that information.
 
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