With engine off, what does your volt meter read?
#1
07-10-2015 | 03:43 PM
Thread Starter
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Tourer
Joined: Jan 2012
Posts: 497
Likes: 11
From: Tucson
With engine off, what does your volt meter read?
I am curious if I have a weak battery on my 2014 Street Glide. I have a slightly slow start.
With engine running, the volt meter in faring dash shows 14 volts. When I turn the engine off, but leave accessories **** on, the volt meter in dash shows exactly 12. Is this normal?
With engine running, the volt meter in faring dash shows 14 volts. When I turn the engine off, but leave accessories **** on, the volt meter in dash shows exactly 12. Is this normal?
#4
07-10-2015 | 04:42 PM
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Joined: Jan 2012
Posts: 4,059
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From: Oklahoma
The factory volt meters are notoriously inaccurate. They are not diagnostic or trouble shooting instruments. They are more "trend" instruments, is the reading today different than it was yesterday or last week? Is it different now than what I am used to? Battery health is best determined with a real volt meter connected to the battery terminals and a high rate discharge (battery capacity) check. At rest your battery should be at least 12.6 volts, checked with a volt/ohm meter, not the "best guess" indicator in your fairing.
What sort of riding have you been doing lately? Trips of at least 10 miles or a bunch of short runs of a couple of miles each? Several short runs without 10 to 20 miles minimum to recharge the battery will cause your symptoms. If your battery is 2 years old or older, it may well have seen better days. Do you have a maintainer? If you have a charger/maintainer hook it up and let it fully charge the battery. If the starter still seems sluggish, take the fully charged battery to a motorcycle place or an Autozone type of place for the capacity check. If it flunks that check, you have your answer. If it passes, you will need to start checking cable connections on your scooter, both ends of the battery cables, not just the battery ends. Some guys have had a sneaky cable problem, the cable was eaten away down inside the insulation and only one or two cable strands were left to carry the heavy starting load.That is less common now with the sealed batteries.
With our batteries being right behind the rear jug and having an exhaust pipe very close the batteries get a good baking, at least in the summer time. Odds favor your needing a new battery.
What sort of riding have you been doing lately? Trips of at least 10 miles or a bunch of short runs of a couple of miles each? Several short runs without 10 to 20 miles minimum to recharge the battery will cause your symptoms. If your battery is 2 years old or older, it may well have seen better days. Do you have a maintainer? If you have a charger/maintainer hook it up and let it fully charge the battery. If the starter still seems sluggish, take the fully charged battery to a motorcycle place or an Autozone type of place for the capacity check. If it flunks that check, you have your answer. If it passes, you will need to start checking cable connections on your scooter, both ends of the battery cables, not just the battery ends. Some guys have had a sneaky cable problem, the cable was eaten away down inside the insulation and only one or two cable strands were left to carry the heavy starting load.That is less common now with the sealed batteries.
With our batteries being right behind the rear jug and having an exhaust pipe very close the batteries get a good baking, at least in the summer time. Odds favor your needing a new battery.
#7
07-10-2015 | 05:09 PM
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From: along the shore of Mishigami
As posted earlier you could do a voltage test across the terminals for an accurate test or put the voltmeter in the charger pigtail and test your voltage from that point. If the battery shows 12.8v the service manual lists this as 100% charged. This can be done (pigtail) with ignition switch off.
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#8
07-10-2015 | 05:21 PM
Seasoned HDF Member
Joined: Mar 2010
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From: Honah Lee
My 2 cents to normal plus a little extra.....
After a good 24+ hour maintenance low amperage charge, with the charge light in the solid green and the battery has set about 24 hours off charge, voltage should be about 12.8 volts.
12.8 = full charged
12.6 = 75% charged
12.3 = 50% charged (Lot of new modern cars with system protection will not even click at this point but will have good headlight beams showing)
12.0 =25% charged
Always check both the terminals at the battery lead and also at the terminal on the wire. That helps to verify connection.
With a DC volt meter (one that has a feature to lock high and low reading is best) hooked across the battery terminals and reading 12.8 or so, crank motor and while its cranking it should not drop below about 9.6 volts and as soon as it starts and throttled up to 2000 rpm, voltage should read around 14.8 volts. The 2000 rpm is the bench mark standard. Ignore idle output. Ignore output above 2000rpm unless it exceeds 14.9 volts. That is a sure indication that regulator is bad.
The crank check shows a rough check of the reserve amperage capacity of the battery while cranking with a 150-200 amp load on it. The 14.8 shows a good alternator and if you leave it on a while as the regulatory will drop the voltage a little showing itself working. However, with the lights and stuff always on, it will never drop back much. If you have a lot of options, most modern bikes will not show 14.8 charging volts at idle but stock newer bikes will be close. Older bikes with lower amperage output not so much. However, 2000 rpm is the bench mark for the standard 14.8 volts.
If you think battery is good and something is draining it sitting, now would be a good time to check for drain problems. Go to Harbor Freight and get you a AC/DC meter for under $25 or so. http://www.harborfreight.com/ac-dc-d...ter-37772.html Make sure it has DC amps draw, DC voltage, resistance and AC voltage. Key off. Remove the negative cable off the battery. Set meter on DC amps. Hook the meter lead to cable and the other to battery. How many milliamps (mA) is it drawing? It should be no more then 6 mA which is the ECM (1), speedometer (1), tac,TSSM (1),HFSM (1) and voltage regulator (1)
When a battery wears out, a good charge will show fairly good voltage, but the battery can still have very low amperage capacity which will show in the crude crank test above, but it really should be checked after a good charge by removing it from bike and getting a free check at a place like AutoZone that has a fancy load meter check that gives you a print out of the battery health. Battery MUST BE CHARGED to check it. Be sure they set their meter to correct cold cranking amperage stated on the battery. Never charge the AGM absorbed glass mat battery with a regular car battery charger unless it is a newer one that says safe with this type of battery. Also, by taking battery out you now know you have good connections. Vibration tends to loosen the connections or a little corrosion will prevent charging or cause starting problems.
Using the maintenance charger can get more years from a battery but be careful here. You do not want the last start 5 miles from home. If it still grunts when you first hit starter or kicks back with a bang, replace it. After a few years, charge and pull battery and have it checked for cold cranking amperage ever spring. Even then, if it grunts most ever start, I would replace it. If they have one that fits your bike, Wal-Mart's AGM absorbed glass mat battery is just as good as any for one third to half the money of a Harley Battery. Do not jump, push start or run bike with a half dead battery except in an emergency. If a bike battery is down and you jump it, throwing all that amps to it from a big car battery especially one that is running can wreck a bike regulator or charging system. Charging a worn out battery can kill alternator stator or the voltage regulator or both. Probably ending in a big dollar repair.
It is also a good idea to always check your battery at 2000 RPM with your meter set to AC. If by chance, the regulator goes bad, sometimes it will let AC come thru. That is a sure sign of a bad regulator. The older stators with two wires are a two phase AC system. Lot of people call it a single phase but it is two phase. The AC voltage you see appears single since you check it AC across the two wires since there is no earth ground. If you were to check one wire to an earth ground, it would show one half the voltage that you would see when you check the two wires together on the bike. Same with the other. Together they double and are two phase. The newer three-wire system is a 3-phase AC system for the higher amperage output.
Also remember, when starting a Harley, hit the starter and hold it in till it is firing on both cylinders and running before letting up. There is a fraction of a second more for a long stroke Harley then a multi-cylinder car for it to get going. If you do not do this, it will kick back with a bang, sneeze thru the intake or crank a lot longer the second time or shame on you the third time. Also, if you have a habit of doing this, the starter solenoid switch contact will only have half the life it could. You cannot hurt the starter. The starter gear has a sprag clutch. There are drive pins in it that as the gas motor catches and run, it outruns the starter motor drive and disengages it from the electric motor. If you hold it in a little too long and listen carefully, you will hear the sprag clutch run up the ramps and slip. Makes a sizzle hum. This will show you your starter sprag clutch is OK.
After a good 24+ hour maintenance low amperage charge, with the charge light in the solid green and the battery has set about 24 hours off charge, voltage should be about 12.8 volts.
12.8 = full charged
12.6 = 75% charged
12.3 = 50% charged (Lot of new modern cars with system protection will not even click at this point but will have good headlight beams showing)
12.0 =25% charged
Always check both the terminals at the battery lead and also at the terminal on the wire. That helps to verify connection.
With a DC volt meter (one that has a feature to lock high and low reading is best) hooked across the battery terminals and reading 12.8 or so, crank motor and while its cranking it should not drop below about 9.6 volts and as soon as it starts and throttled up to 2000 rpm, voltage should read around 14.8 volts. The 2000 rpm is the bench mark standard. Ignore idle output. Ignore output above 2000rpm unless it exceeds 14.9 volts. That is a sure indication that regulator is bad.
The crank check shows a rough check of the reserve amperage capacity of the battery while cranking with a 150-200 amp load on it. The 14.8 shows a good alternator and if you leave it on a while as the regulatory will drop the voltage a little showing itself working. However, with the lights and stuff always on, it will never drop back much. If you have a lot of options, most modern bikes will not show 14.8 charging volts at idle but stock newer bikes will be close. Older bikes with lower amperage output not so much. However, 2000 rpm is the bench mark for the standard 14.8 volts.
If you think battery is good and something is draining it sitting, now would be a good time to check for drain problems. Go to Harbor Freight and get you a AC/DC meter for under $25 or so. http://www.harborfreight.com/ac-dc-d...ter-37772.html Make sure it has DC amps draw, DC voltage, resistance and AC voltage. Key off. Remove the negative cable off the battery. Set meter on DC amps. Hook the meter lead to cable and the other to battery. How many milliamps (mA) is it drawing? It should be no more then 6 mA which is the ECM (1), speedometer (1), tac,TSSM (1),HFSM (1) and voltage regulator (1)
When a battery wears out, a good charge will show fairly good voltage, but the battery can still have very low amperage capacity which will show in the crude crank test above, but it really should be checked after a good charge by removing it from bike and getting a free check at a place like AutoZone that has a fancy load meter check that gives you a print out of the battery health. Battery MUST BE CHARGED to check it. Be sure they set their meter to correct cold cranking amperage stated on the battery. Never charge the AGM absorbed glass mat battery with a regular car battery charger unless it is a newer one that says safe with this type of battery. Also, by taking battery out you now know you have good connections. Vibration tends to loosen the connections or a little corrosion will prevent charging or cause starting problems.
Using the maintenance charger can get more years from a battery but be careful here. You do not want the last start 5 miles from home. If it still grunts when you first hit starter or kicks back with a bang, replace it. After a few years, charge and pull battery and have it checked for cold cranking amperage ever spring. Even then, if it grunts most ever start, I would replace it. If they have one that fits your bike, Wal-Mart's AGM absorbed glass mat battery is just as good as any for one third to half the money of a Harley Battery. Do not jump, push start or run bike with a half dead battery except in an emergency. If a bike battery is down and you jump it, throwing all that amps to it from a big car battery especially one that is running can wreck a bike regulator or charging system. Charging a worn out battery can kill alternator stator or the voltage regulator or both. Probably ending in a big dollar repair.
It is also a good idea to always check your battery at 2000 RPM with your meter set to AC. If by chance, the regulator goes bad, sometimes it will let AC come thru. That is a sure sign of a bad regulator. The older stators with two wires are a two phase AC system. Lot of people call it a single phase but it is two phase. The AC voltage you see appears single since you check it AC across the two wires since there is no earth ground. If you were to check one wire to an earth ground, it would show one half the voltage that you would see when you check the two wires together on the bike. Same with the other. Together they double and are two phase. The newer three-wire system is a 3-phase AC system for the higher amperage output.
Also remember, when starting a Harley, hit the starter and hold it in till it is firing on both cylinders and running before letting up. There is a fraction of a second more for a long stroke Harley then a multi-cylinder car for it to get going. If you do not do this, it will kick back with a bang, sneeze thru the intake or crank a lot longer the second time or shame on you the third time. Also, if you have a habit of doing this, the starter solenoid switch contact will only have half the life it could. You cannot hurt the starter. The starter gear has a sprag clutch. There are drive pins in it that as the gas motor catches and run, it outruns the starter motor drive and disengages it from the electric motor. If you hold it in a little too long and listen carefully, you will hear the sprag clutch run up the ramps and slip. Makes a sizzle hum. This will show you your starter sprag clutch is OK.
#9
07-10-2015 | 05:24 PM
Club Member
Joined: Apr 2013
Posts: 7,352
Likes: 7,599
From: Utah
