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ToSlow

ToSlow

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My 2011 KLR had a dead battery this morning, hooked up the trickle charger for a few hr to charge it.

I’ve got a voltage indicator on my bike so after it fired up it’s only showing 12.9 at the highest, after turning on acc, it will go down to 11.5

Battery holds a charge after doing a load test.

My guess is rectifier, but thinking it might also be a stator. Looking for an educated guess

Thx
 
My first thought is "what is the accessory"
 
11.5 V is too low before you even begin cranking.

After you take the battery off the trickle charger there will be a residual surface charge, so the 12.9V reading may not accurate.

Let it sit for a few hours to let the voltage settle, then measure again.

If you suspect the stator, measure the voltage across the terminals when the bike is running above idle rpms. Should read 14+V.

My guess is that the battery is toast.
 
Lightcycle said:
11.5 V is too low before you even begin cranking.

After you take the battery off the trickle charger there will be a residual surface charge, so the 12.9V reading may not accurate.

Let it sit for a few hours to let the voltage settle, then measure again.

If you suspect the stator, measure the voltage across the terminals when the bike is running above idle rpms. Should read 14+V.

My guess is that the battery is toast.
Click to expand...
I rode the bike for about an hr, came back shut it off and loaded the battery again, holds charge around 11v. I'll let it sit for anouther few and check it in the morning. Although it wasn't giving me any troubles battery wise
 
How old is the battery ?
Have you had it load tested ?
When the bike is running are you getting at least 13.5 volts at the battery terminals ?
Every spring is the same drill...
 
TK4 said:
How old is the battery ?
Have you had it load tested ?
When the bike is running are you getting at least 13.5 volts at the battery terminals ?
Every spring is the same drill...
Click to expand...
Battery is a couple yrs old, kept inside in winter and trickled. load test i'm doing is turning on lights and highbeen plus led's. signals

Battery is only showing 11.9 when sitting not running, should be around 13.2 or better, revving the bike to 3000rpm it will show up to 13.2 give or take.

I'm thinking LC might be on to something and maybe the battery has crapped out?
 
ToSlow said:
Looking for an educated guess
Click to expand...
The educated don't guess, the educated test and verify.
Got a multi meter? You need one.
Charge the battery at no more than 10% of it's capacity (less than 2 amps) overnight, remove from charger, let it sit for 2 hours and test the voltage. If it is less than 12.7v the battery has issues.
Disconnect the stator from the regulator (the plug with 3 wires).
pull the ignition fuse.
Put the battery back in the bike and hook it up. What's the voltage?
Turn on the bike. What is the voltage
Hold the starter button down. The voltage should stay 10v or above for 10 seconds while the starter turns. (That's a valid "Load test")
put the ignition fuse back in and start the bike.
Test the 3 stator leads for AC voltage, 3 wires/phases need three tests (a&b, b&c, c&a). At idle you need at least 35 v AC, you want over 65-70 v AC at 3000 - 3500 rpm on a modern bike.
If you see those voltages the stator is good.
Plug the regulator back in.
What the voltage across the battery at idle, you NEED 13.5v DC, you want >14v DC
At 3000-3500 you should see >14.2v DC, no more than 15v
If you see those voltages your regulator is good.
Check across the battery for AC voltage.
if you see more than a couple of volts AC, you have a rectifier problem. (A COUPLE of volts... a GOOD rectifier will show 1-1.5 v AC, a ****** rectifier will show 4-5... it's a judgement call. The more AC voltage at the battery the shorter your battery life. Lead acid batteries don't like AC voltage)
These tests take about 15-20 minutes, works on any 12v system
 
bitzz said:
The educated don't guess, the educated test and verify.
Got a multi meter? You need one.
Charge the battery at no more than 10% of it's capacity (less than 2 amps) overnight, remove from charger, let it sit for 2 hours and test the voltage. If it is less than 12.7v the battery has issues.
Disconnect the stator from the regulator (the plug with 3 wires).
pull the ignition fuse.
Put the battery back in the bike and hook it up. What's the voltage?
Turn on the bike. What is the voltage
Hold the starter button down. The voltage should stay 10v or above for 10 seconds while the starter turns. (That's a valid "Load test")
put the ignition fuse back in and start the bike.
Test the 3 stator leads for AC voltage, 3 wires/phases need three tests (a&b, b&c, c&a). At idle you need at least 35 v AC, you want over 65-70 v AC at 3000 - 3500 rpm on a modern bike.
If you see those voltages the stator is good.
Plug the regulator back in.
What the voltage across the battery at idle, you NEED 13.5v DC, you want >14v DC
At 3000-3500 you should see >14.2v DC, no more than 15v
If you see those voltages your regulator is good.
Check across the battery for AC voltage.
if you see more than a couple of volts AC, you have a rectifier problem. (A COUPLE of volts... a GOOD rectifier will show 1-1.5 v AC, a ****** rectifier will show 4-5... it's a judgement call. The more AC voltage at the battery the shorter your battery life. Lead acid batteries don't like AC voltage)
These tests take about 15-20 minutes, works on any 12v system
Click to expand...
Make this a sticky...
 
@ToSlow based on what you describe (under-voltage while engine running), it's either your stator isn't generating enough AC voltage, the rectifier isn't converting it to DC voltage, or you have resistance in the wiring between any of them to the battery (common on some bikes that the connector between the stator and R/R builds up resistance and overheats/melts/burns up).

Regardless of the state of your battery (fully charged, undercharged, or completely dead), you should always see around 14v at the battery terminals with the engine running if those components of the charging system are all good.
 
You battery is pooched, but that's only the first part.

Your battery could be at its end of life, or something could have killed it.

A proper battery load test is applying a load of 50% of the CCA for 15 seconds to a fully charged battery. Voltage must not drop below 10.6v at any point. I bet your battery will drop out with very little actual load.

Do all of bitzz's tests above and see where that takes you. Once you replace the battery, do the tests again and make sure your charging system is not over/under charging the battery.
 
Torren said:
You battery is pooched, but that's only the first part.

Your battery could be at its end of life, or something could have killed it.

A proper battery load test is applying a load of 50% of the CCA for 15 seconds to a fully charged battery. Voltage must not drop below 10.6v at any point. I bet your battery will drop out with very little actual load.

Do all of bitzz's tests above and see where that takes you. Once you replace the battery, do the tests again and make sure your charging system is not over/under charging the battery.
Click to expand...

The battery is fine - it could be charged, it retained a charge after a load test, and it could start the bike. The fact that it was dead means that it wasn't charging while the bike was running, and the low voltage reading with the engine running clearly shows the charging system is not working optimally and undercharging. Stator, wiring, or rectifier.
 
Relax said:
The battery is fine - it could be charged, it retained a charge after a load test, and it could start the bike. The fact that it was dead means that it wasn't charging while the bike was running, and the low voltage reading with the engine running clearly shows the charging system is not working optimally and undercharging. Stator, wiring, or rectifier.
Click to expand...
The battery sure doesn't sound fine to me, and hasn't had a proper load test that I've seen posted.

Half the CCA for 15 secs without dropping to 10.6v is a load test. Going to need a carbon pile to perform the test. Running the lights and every other electrical accessory is not a load test, unless those accessories draw 50% of the battery's CCA.

With a stator/rectifier system proper battery voltage is critical. If the battery is wonky, you'll end up chasing your tail over and over while going over the other parts of the charging system.
 
Torren said:
The battery sure doesn't sound fine to me, and hasn't had a proper load test that I've seen posted.

Half the CCA for 15 secs without dropping to 10.6v is a load test. Going to need a carbon pile to perform the test. Running the lights and every other electrical accessory is not a load test, unless those accessories draw 50% of the battery's CCA.

With a stator/rectifier system proper battery voltage is critical. If the battery is wonky, you'll end up chasing your tail over and over while going over the other parts of the charging system.
Click to expand...

What part about being able to charge the battery and start the bike makes it sound like the battery is bad?
 
Relax said:
What part about being able to charge the battery and start the bike makes it sound like the battery is bad?
Click to expand...
It may start the bike ONCE, but have no residual cranking power. Take the battery out and go to CTC, your local shop or some auto supply stores and have it properly load tested. This isn't rocket science, age (more than 5 years) and quality (Chinesium) of the battery are factors to consider.
Once the good operating condition of the battery has been verified move along to checking the regulator/rectifier and rotor/stator as per bitzz's instructions. Every spring it's the same story.
 
Relax said:
What part about being able to charge the battery and start the bike makes it sound like the battery is bad?
Click to expand...
The part where the battery never even came close to showing a proper voltage, even after being on a charger.

Bike sits at 11.9v not running and goes to 13.2v running so we know the charging system is working to at least some degree. May not be much, but it's charging and the battery is unable to store it.

Not saying that the battery is the only or the original problem, but it is clearly an issue and needs to be sorted.
 
Torren said:
The part where the battery never even came close to showing a proper voltage, even after being on a charger.

Bike sits at 11.9v not running and goes to 13.2v running so we know the charging system is working to at least some degree. May not be much, but it's charging and the battery is unable to store it.

Not saying that the battery is the only or the original problem, but it is clearly an issue and needs to be sorted.
Click to expand...

I think that's where we're interpreting it differently and need clarification. I didn't see that the 11.9v was after being on a charger, I read it as the recovery voltage after sitting from the last reading of 11v. Also the original post mentioned only 11.5v when the lights were on, so if the bike was being ridden with the lights on, that would also explain why the battery is down to 11v.

Now if the battery was fully charged to 13v and after sitting it dropped to 11.9 (or only took a charge to 11.9), then I agree the battery is bad.

In any case, we know the charging system is under-voltage, and you don't need a battery to test the stator or wiring condition, so might as well check those out now.
 
Oh, also a trickle charger for only a few hours wouldn't bring a fully discharged battery back up to 13v (maybe the surface charge). My 0.8a charger takes at least 24 hours depending on the size of the battery.
 
Relax said:
I think that's where we're interpreting it differently and need clarification. I didn't see that the 11.9v was after being on a charger, I read it as the recovery voltage after sitting from the last reading of 11v. Also the original post mentioned only 11.5v when the lights were on, so if the bike was being ridden with the lights on, that would also explain why the battery is down to 11v.

Now if the battery was fully charged to 13v and after sitting it dropped to 11.9 (or only took a charge to 11.9), then I agree the battery is bad.

In any case, we know the charging system is under-voltage, and you don't need a battery to test the stator or wiring condition, so might as well check those out now.
Click to expand...
We don't know that the bike is under charging. We know that the battery had a low resting voltage and we don't know why yet.

Trying to diagnose a charging system with a bad battery is like a doctor trying to raise a patient's low blood pressure while ignoring a severed artery.

Even a short charge with an anemic charger should show a surface charge well over 13v with a healthy battery.

Go ahead and spend time diagnosing a charging system that has a giant artificial load / voltage sponge attached to it. Personally I'd rather do it properly the first time.
 
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Torren said:
We don't know that the bike is under charging. We know that the battery had a low resting voltage and we don't know why yet.

Trying to diagnose a charging system with a bad battery is like a doctor trying to raise a patient's low blood pressure while ignoring a severed artery.

Even a short charge with an anemic charger should show a surface charge well over 13v with a healthy battery.

Go ahead and spend time diagnosing a charging system that has a giant artificial load / voltage sponge attached to it. Personally I'd rather do it properly the first time.
Click to expand...

You're basically making the same argument as me, but you're assuming the battery is dead whereas I'm assuming it isn't. In over 40 years I've never seen a battery that was working fine one day then suddenly become a "sponge" and soak up enough voltage from the regulator to materially affect the reading. All bets are off if you pick one up from the dumpster that's been sitting for a decade.

I'm suggesting some very quick and easy tests that disconnects the battery, so it doesn't matter what condition it's in. It takes a few minutes to unplug the R/R connector to get an AC reading. How long does it take to remove the battery, drive it to CT where they always tell you it's dead, return and reinstall it? And even if you ordered one online, are you just going to stare at the bike while you're waiting for it to arrive?
 
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