Why won’t my bike start

[Hango]

Ok here are the voltages
fyi I rode the bike 170 miles yesterday
battery key off
12.19
key on w kill switch on
11.74
starting
10.5
key off after trying to start
12.04
It is now on the trickle charger, I bought a new battery last week but did not charge it.
do these numbers indicate anything?
thanks
Jim

[gsrick]

It may be on it's last legs, but you need to test it fully charged and after it's settled. I'd wait at least 30 minutes before jumping in the pool. Whoops, wrong warning. lol Give it 10-15 minutes to settle down then check you numbers again. If it starts check the battery voltage at idle and while revving it up to 5K.

[Steve]

Thanks for the numbers, I will insert comments in your quote.

battery key off 12.19
Evidently your battery is not fully charged. A wet-cell battery should be 12.6, a sealed battery should be 12.8.

key on w kill switch on 11.74
With this "standard" load, it should be over 12, more like 12.2.

starting 10.5
Really marginal here, should be at least a volt higher, close to 11.5.

key off after trying to start 12.04
I realize no charging happened, but should be closer to 12.5 to 12.7, depending on type of battery.

It is now on the trickle charger, I bought a new battery last week but did not charge it.
I don't know if it is still common practice, but I learned to ALWAYS charge a battery before using it. With the older batteries (again, not sure if it is still that way with newer batteries), they seemed to "lock in" the current state of charge and would not go past it if you applied a heavy load (starting the bike) before achieving a full charge.

do these numbers indicate anything?
Yes. Your battery is not fully-charged. In its state of discharge, the voltage was dipping low enough that there might not be anything left to provide enough spark to start. To confirm this, connect the bike to your car with jumper cables, but make sure the car is NOT running at any time while connected. Turn the bike ignition ON, press the starter, it should start nicely.

thanks
You're welcome.

Jim
Steve

.

[Hango]

Are these numbers low? Where should they be? Wouldn’t riding 170 miles fully charge the battery? The battery is a 1 week old “big crank”.
Jim

[Hango]

Sorry Steve as you were posting I was asking.
Definitely follow your instructions and jump the bike.

[Steve]

Remember, ... CAR NOT RUNNING.

.

[Brendan W]

Are these numbers low? Where should they be? Wouldn’t riding 170 miles fully charge the battery? The battery is a 1 week old “big crank”.
Jim

No amount of riding will charge the battery if the charging system is not delivering. The charging voltage has to be above the battery voltage to get charge to go in, think foot pump and tyre. Typically at idle you should be seeing 13+ volts at idle and rising to 14.4 ish at 5000 rpm. At shutdown the voltage will be of the order of 13 volts falling slowly over several hours to 12.6 if the battery is fully charged.
I bought a new wet battery last month and despite claims that it would be ready to go it took half a day on the charger to top out.

[Steve]

I bought a new wet battery last month and despite claims that it would be ready to go it took half a day on the charger to top out.

The vendors fall into one of two categories:
1. They are ignorant and truly believe the battery is "ready to go".
2. They know it is somewhat limited, tell you it's ready so you will lock it into its compromised condition. It will then fail quicker, you will buy a new battery sooner.

The good news is that even a less-than-fully-charged battery works better than the dead battery you are replacing, so you think everything is just hunky-dory and keep going in ignorance.

Even if they say it doesn't need it, charge the battery before you use it.

.

[Hango]

Sorry Steve I was not able to jump the bike,from a non running car, however I did take voltage readings after leaving my battery tender trickle charger on over night.
battery with key off
13.04
battery with key on
12.45
starting bike
11.4
after start with key off
12.8
btw the bike started right up with a full charge.
i will ride it around 50 miles and check the voltages again, this should tell me if there is still a problem.
Jim

[Steve]

Compare those numbers with what I was suggesting in post #18. More comments added.

Sorry Steve I was not able to jump the bike,from a non running car, however I did take voltage readings after leaving my battery tender trickle charger on over night.
battery with key off - 13.04
A wet-cell battery should be 12.6, a sealed battery should be 12.8.
I am guessing that you did not wait very long after removing the charger.

battery with key on - 12.45
it should be over 12, more like 12.2.
Probably still just a bit high from a very recent charger disconnect.

starting bike - 11.4
close to 11.5.

after start with key off - 12.8
should be closer to 12.5 to 12.7, depending on type of battery.

btw the bike started right up with a full charge.
Amazing, ain't it?

.

[Brendan W]

i will ride it around 50 miles and check the voltages again, this should tell me if there is still a problem.
Jim

Before you set off for the 50 miles check that the charging system is actually charging.
13 +/- 0.2 at idle
14.2 +/- 0.2 at 5000 rpm