How to tell if your battery is dead: Difference between revisions

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The following is important information for the DIY rider. Quite often a seemingly impenetrable electrical problem can be traced to a battery that is no longer serviceable. This should be the first thing you look at.

==== Symptoms ====

== Symptoms ==

Here are the classic symptoms of battery failure:

Sometimes a battery just dies. Not necessarily from neglect, age, or use. It just dies. Car batteries can give some advance warning when they start to go, but tiny bike batteries are more likely to be fine one moment and dead the next. This normally comes from sulfates building up along the bottom and shorting out a couple of the lead plates. It's difficult for many people to trouble-shoot because they'll just toss a voltmeter on the battery, see that it shows 12v DC, and right away say it's fine. The truth is, if the resting voltage (after sitting, not on a charger) is below 12.2, that battery needs to be replaced. Below 12v and it's dead, for all practical purposes.

A 12 volt battery that has only 12.0 volts is a dead battery. This sounds totally wacky, but it is true.

Here are the classic symptoms of battery failure. If any of these are present, test the battery as outlined below.

* Gauges on (neutral, oil and temp) but the starter won't catch

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* Engine keeps coughing, but tach is much higher than it should be, or it is bouncing wildly from low to high.

* Engine surges with turn signal on.

* When trying to start, you hear a click and all the lights go dead.

* You try to start and you hear [[When I try to start my bike I hear a chattering noise|clickclickclickclickclick]] - The clicks can come so fast they sound like a robot cat purring.

Sometimes a battery just dies. Not necessarily from neglect, age, or use. It just dies. Car batteries can give some advance warning when they start to go, but tiny bike batteries are more likely to be fine one moment and dead the next. This normally comes from sulfates building up along the bottom and shorting out a couple of the lead plates. It's difficult for many people to trouble-shoot because they'll just toss a voltmeter on the battery, see that it shows 12v DC, and right away say it's fine. The truth is, if the resting voltage (after sitting, not on a charger) is below 12.2, that battery needs to be replaced. Below 12v and it's dead, for all practical purposes.

== Diagnosis ==

==== Diagnosis ====

To confirm the condition of your battery, you'll need a [http://en.wikipedia.org/wiki/Multimeter multimeter]. Follow [[How to read a multimeter|these instructions]] if you don't already know how to use a multimeter, and check the following values:

(Check the voltage at the battery terminals, and make sure to record the voltage down to the tenths: 12.6v vs. 12v)

To confirm the condition of your battery, you'll need a [http://en.wikipedia.org/wiki/Multimeter multimeter]. Follow [[How to read a multimeter|these instructions]] if you don't already know how to use a multimeter. Check the voltage at the battery terminals, and make sure to record the voltage down to the tenths: 12.6v vs. 12v. Check the following values:

* After the bike has been sitting for days, key off: No lower than 12.2v, and even that's pretty low. You really want more like 12.6-12.8.

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* In normal rpm range (4000-9000): 13.8v is ideal, but anything 13.5-13.8 is OK.

* Immediately (within half an hour) after a ride of 10-15 miles at over 4000 rpm, engine and key off: 12.8v or more.

* Immediately (within half an hour) after a ride of at least 10-15 miles at over 4000 rpm, engine and key off: 12.8v or more.

* A day or two after that ride, key off: 12.6v or higher

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If the "normal rpm range" voltage reads higher than 13.8v, your voltage regulator may be failing. This will boil the battery dry from overcharging, and eventually start popping lights and causing other damage. This should be fixed as soon as possible.

'''Note''': ~~Older~~ bikes, and the occasional new battery, are not of the sealed variety. They will periodically require ~~electrolyte~~ to be added. Make sure the electrolyte level is full, and if it isn't, top it up with ''distilled'' water. A battery with low electrolyte will mimic the symptoms of a dying battery, but can be fully revived by adding distilled water and charging. You can tell if your battery is sealed by looking for a row of six caps (or some kind of removable strip) across the top of the battery casing.

'''Note''': Batteries on older bikes, and the occasional new battery, are not of the sealed variety. They will periodically require water to be added. Make sure the electrolyte level is full, and if it isn't, top it up with ''distilled'' water. A battery with low electrolyte will mimic the symptoms of a dying battery, but can be fully revived by adding distilled water and charging. You can tell if your battery is sealed by looking for a row of six caps (or some kind of removable strip) across the top of the battery casing.

==== Further Reading ====

== Further Reading ==

If you'd like to know more about lead-acid batteries and their care and feeding, Yuasa produces a very comprehensive [http://www.yuasabatteries.com/pdfs/TechMan.pdf technical manual] (PDF) that explains all this in detail. Yuasa batteries have a deserved reputation for excellence, which is usually reflected in their price.

@@ Line 4: / Line 4: @@
 The following is important information for the DIY rider. Quite often a seemingly impenetrable electrical problem can be traced to a battery that is no longer serviceable. This should be the first thing you look at.
-==== Symptoms ====
+== Symptoms ==
-Here are the classic symptoms of battery failure:
+Sometimes a battery just dies. Not necessarily from neglect, age, or use. It just dies. Car batteries can give some advance warning when they start to go, but tiny bike batteries are more likely to be fine one moment and dead the next. This normally comes from sulfates building up along the bottom and shorting out a couple of the lead plates. It's difficult for many people to trouble-shoot because they'll just toss a voltmeter on the battery, see that it shows 12v DC, and right away say it's fine. The truth is, if the resting voltage (after sitting, not on a charger) is below 12.2, that battery needs to be replaced. Below 12v and it's dead, for all practical purposes.
+A 12 volt battery that has only 12.0 volts is a dead battery. This sounds totally wacky, but it is true.
+Here are the classic symptoms of battery failure. If any of these are present, test the battery as outlined below.
 * Gauges on (neutral, oil and temp) but the starter won't catch
@@ Line 12: / Line 16: @@
 * Engine keeps coughing, but tach is much higher than it should be, or it is bouncing wildly from low to high.
 * Engine surges with turn signal on.
+* When trying to start, you hear a click and all the lights go dead.
+* You try to start and you hear [[When I try to start my bike I hear a chattering noise|clickclickclickclickclick]] - The clicks can come so fast they sound like a robot cat purring.
-Sometimes a battery just dies. Not necessarily from neglect, age, or use. It just dies. Car batteries can give some advance warning when they start to go, but tiny bike batteries are more likely to be fine one moment and dead the next. This normally comes from sulfates building up along the bottom and shorting out a couple of the lead plates. It's difficult for many people to trouble-shoot because they'll just toss a voltmeter on the battery, see that it shows 12v DC, and right away say it's fine. The truth is, if the resting voltage (after sitting, not on a charger) is below 12.2, that battery needs to be replaced. Below 12v and it's dead, for all practical purposes.
+== Diagnosis ==
-==== Diagnosis ====
-To confirm the condition of your battery, you'll need a [http://en.wikipedia.org/wiki/Multimeter multimeter].  Follow [[How to read a multimeter|these instructions]] if you don't already know how to use a multimeter, and check the following values:
-(Check the voltage at the battery terminals, and make sure to record the voltage down to the tenths: 12.6v vs. 12v)
+To confirm the condition of your battery, you'll need a [http://en.wikipedia.org/wiki/Multimeter multimeter].  Follow [[How to read a multimeter|these instructions]] if you don't already know how to use a multimeter. Check the voltage at the battery terminals, and make sure to record the voltage down to the tenths: 12.6v vs. 12v. Check the following values:
 * After the bike has been sitting for days, key off: No lower than 12.2v, and even that's pretty low. You really want more like 12.6-12.8.
@@ Line 29: / Line 31: @@
 * In normal rpm range (4000-9000): 13.8v is ideal, but anything 13.5-13.8 is OK.
-* Immediately (within half an hour) after a ride of 10-15 miles at over 4000 rpm, engine and key off: 12.8v or more.
+* Immediately (within half an hour) after a ride of at least 10-15 miles at over 4000 rpm, engine and key off: 12.8v or more.
 * A day or two after that ride, key off: 12.6v or higher
@@ Line 37: / Line 39: @@
 If the "normal rpm range" voltage reads higher than 13.8v, your voltage regulator may be failing.  This will boil the battery dry from overcharging, and eventually start popping lights and causing other damage. This should be fixed as soon as possible.
-'''Note''': Older bikes, and the occasional new battery, are not of the sealed variety.  They will periodically require electrolyte to be added.  Make sure the electrolyte level is full, and if it isn't, top it up with ''distilled'' water.  A battery with low electrolyte will mimic the symptoms of a dying battery, but can be fully revived by adding distilled water and charging.  You can tell if your battery is sealed by looking for a row of six caps (or some kind of removable strip) across the top of the battery casing.
+'''Note''': Batteries on older bikes, and the occasional new battery, are not of the sealed variety.  They will periodically require water to be added.  Make sure the electrolyte level is full, and if it isn't, top it up with ''distilled'' water.  A battery with low electrolyte will mimic the symptoms of a dying battery, but can be fully revived by adding distilled water and charging.  You can tell if your battery is sealed by looking for a row of six caps (or some kind of removable strip) across the top of the battery casing.
-==== Further Reading ====
+== Further Reading ==
 If you'd like to know more about lead-acid batteries and their care and feeding, Yuasa produces a very comprehensive [http://www.yuasabatteries.com/pdfs/TechMan.pdf technical manual]  (PDF) that explains all this in detail.  Yuasa batteries have a deserved reputation for excellence, which is usually reflected in their price.