To help with my last post i'm asking a new question.

What is the correct voltage for a battery that is either off the bike or on but the bike is off ???

I'm hearing 12.5 to 13.2 is the correct voltage but want to see what everyone else gets for a reading.

Can you guys/girls check esp. if you just got a new battery and post your readings.

I took mine to a bike shop they hooked it up and said it was fine.
Took to Advance Auto Parts and their machine said it needs to be replaced but they didn't know the correct amperage to enter.

Trying to eliminate a bad battery esp. when it costs 127.99 for a gel battery.

Does anybody put theirs on a charger? If so what is the charging amps for you charger? Mine is 1.5A. Too much???? I'm not sure.

I have an 04' f4i w/ 1100 miles.


please help

 

Should be 12.5ish.. i work at autozone and test batteries all day, even motorcycle batteries run 12 volts. I just had to replace mine because it wasnt holding anycharge at all. th new one after filling was 12.6 i think. As far as trickle chargers they usually work on a amp/volt per hour thing sho if its charging at 1.5 it should take about 8 1/2 hours roughly.

 

Yesterday i took out the bike and started it up and it was fine. Heres what i got for readings:

1) 12.5 v b4 starting
2) turn key on: drops to about 12 v
3) turn on engine cut off switch: drops to 11.7 v
4) start: drops to 10.? v
5) once running: climbs to about 14 v then rev the engine and charges at 14.6 v
6) turn on high beam: drops to 14.2 then rev again....back to 14.5 v

turn off for 45 min. come back and restart readings same order as above:
1) 12.5v
2) 11.9v
3) 10.8 -11.0 v
4) 9.?
5) same as above
6) same as above

turn off again and about 10 min. restart and sounds like the battery is almost dead but still starts
1) 12.5v
2) ?
3) 11 v
4) 8.6 v
5) charges to 14.5 v at about 3000 rpms( i think)
6) ?

turn off about 2 mins later and try to restart and i cant. battery is dead

I guess its the battery but i want to check the stater and see how many amps its putting out ( i think thats what im supposed to check, cant remember)
b/c it's charging at about 14.5- 14.6 v so everything is ok with that. It's not overcharging and not undercharging and if it's at 14.5 v it's converting AC to DC.

Is all this correct/making sense?

Please help somebody, there's gotta be someone with some knowledge here.

 

My guess it is also battery if there isn't anything like corroded terminals or a bad ground somewhere. One thing had happened to me in the past was a bad diode in a car alternator allowed the battery to drain when the car sat. But your situation is it starts a few times then won't, it doesn't have the time to drain, it just doesn't have enough capacity. Sounds like a weak cell, even dropping to 9-10 volts sounds low.

I went and checked mine.

12.74 resting- rode it 8 hours ago
didn't check key on (have HID, would be different anyway)

started and running with revs at about 5000 goes from 13.71 then climbs, past 14.2 then I got bored.

good luck.

 

I'm pretty sure its the battery too i just want to make sure by checking the alternator's output. The terminals are all good too.

Thanks for the help. I know....it's very boring. But going alittle further and checking other stuff like the alternator, regulator, amps, the battery leak test, etc. is good practice for just good old know how.

 

You may also want to see if you have a high parasitic draw on your battery. With everything off test the current draw from the battery. Let it sit about two minutes after hooking your meter up to make sure it stabalizes (sometimes the computer kicks on for a short period when getting reenergized). If you don't know how to test for current draw let me know and I'll explain.

 

What type of bike is it? Cuz I had the same problem with my 98 cbr 600f3 and it wasnt the battery or the stator...it was the regulator/rectifier that was bad on it.

There is a test you can do with a multimeter that either tells if its the stator or the battery....if you would like i can scan the test onto my pc and put it up on here.....

 

delta - did you ever figure out what was wrong? Was it just your battery?