Minimum battery voltage for starting?

[posplayr]

When I look at the Suzuki manuals, it seems they avoid much discussion of battery voltage...
it's pointless to check the voltage of a "resting battery" until it's rested.... overnight is best. ..because the "surface charge" of a "just-off-charging" is ephemeral. I'd be very suprised to see your battery with 12.7 volts after a rest if it won't start your bike. But I wouldn't strain to see it if it doesn't....

Nowhere are used batteries discussed as viable, yet few people have brand new ones.... it seems to me pretty obvious that old batteries have less capacity. They don't take full charge anymore and so, it follows, "battery resting voltage" drops too. But a motorcycle can go along quite well for a long time with a battery that is not brand new; that does not exibit 12.65 volts at rest...

Jake if you read this perhaps you realize why I answered your original question with a 6 decimal point precision. Or perhaps it is too subtle, but the number of decimal points is in direct propostion to the irrelevance of the question asked.

You are not going to figure out the relationship of SOC to battery voltage by mucking around with a voltmeter in your garage. A voltmeter is very valuable but you not only need to know how to use the voltmeter (a challenge for some) but more importantly it is the relationship between the readings and the SOC and the many variables that your will need to understand to come to any valid conclusion. Asking for a minimum voltage it is very clear you did not understand this.

[oregonjake]

I am not good at electrical, that has always been my weak point. I will read the SOC in the quick test link, and the rain stopped so I will do all the tests again and report the results this afternoon.

[oregonjake]

Okay, I think problem has been tracked down. Doing the stator AC voltage output test, one lead shows no voltage at all.Other two show over 60 volts. Am I correct in believing that the stator is bad now? With one phase showing nothing that is a positive sign that the stator, at least one phase of it is fried. Correct? Even after assembling and starting, I notice the idiot lights get brighter as I rev the engine, but is it safe to assume that there just isn't enough juice to keep the battery fully charged, am I right?

Jeez, just when I thought had everything sorted out...

[oregonjake]

Another problem cropped up. I decided to pull the cover off the fuse block. I found the headlight fuse almost completely melted but not blown.





Never seen this before. I know that the stator/R/R problem has one phase of the alternator going through the RH switch and headlight, the wiring harness I got and installed (new to me) had what appeared to be the wiring plug fix (loop back into plug to bypass headlight) yet this happened. I am stumped as to the reasons. I am going to get a replacement stator from a local source, could the stator going bad ( or R/R) be the cause in any way? Suggestions? I know I must be missing something.

[posplayr]

That fuse melted because it was corroded and dirty snd never cleaned like the rest of the bike I assume.

[bonanzadave]

That fuse melted because it was corroded and dirty snd never cleaned like the rest of the bike I assume.

Ding ! and your old battery would crank your bike over but with the headlight on, the starter engaged, and the high resistance in the wires and connectors to your coils chances are your coils are probably seeing less than 9vdc.

[oregonjake]

Let me clarify:

Battery is one year old.

I asked about a headlight on/off switch and if that would help reduce battery strain and no one replied with comment or advice.

When I replaced the wiring harness I did everything recommended here, all the ground connections were correctly mounted, everything tight and cleaned, and all plugs were cleaned and checked.

Coils have correct connectors, also cleaned and checked.

The fuse block was cleaned and checked as well as new fuses.

I apologize for being ignorant but my daddy taught me to ask questions when in doubt. No offense meant to those who have more experience.

Lastly, Miss Bugly is sad that posplayr said she was "dirty and never cleaned" and wants you to know that she has a bath at least once a week, and that any outward appearance of "dirty" is just an opinion and holds no water with her. She says she may look dirty, but inside she is a lady.

[posplayr]

Let me clarify:

You were not very clear; So the fuse melted due to lighting strike or divine intervention?

[mike10]

I got a new battery because my old one tested over 12v just sitting but dropped below 9v when I hit the starter and just kept heading south.

[Gorminrider]

I asked about a headlight on/off switch and if that would help reduce battery strain and no one replied with comment or advice

.
sorry! IMO Mostly the switch is a complication. If your bike starts well (and of course it should!) then the extra load is momentary... If you are having starting trouble, the simplest is to open the headlight bucket and pull the headlight connector.
...however,why not always be sure you have the very best spin of the starter and the hottest spark your 35 year old bike can muster? Maybe you will get the extra crank that starts the bike....but on a bike that has no stock headlight switch, the price for this is complication ..more wires,connectors and contacts that can look pretty ugly and if not done well can be worse than any benefit.......You can Put a toggle switch on it or a more elegant relay that disconnects headlamp when starter button is pushed....
I have a relay on the 650 and the 400's have "stock" light switches.


probably no one answered this in the first place because multiple questions steer the thread on a crooked path.This is peripheral to main question..Iand,it gets hard for other people lurking, looking for help, to find these things