Load testing a battery - how?

[JimH]

When the subject of failing batteries comes up, the question of load testing your battery comes up. How does a person load test their battery and what device or tool do you need to do so?
Thanks in advance,
Jim

[Mikey]

You can ether go to most auto repair stores and they will do it for you, for free in most cases, or if you want your own tester you can buy one at most of those stores also! I like the free part myself!! I am sure that some one will give you the voodoo science of it, but it tests your plates inside your battery under load, if there's a fast drop in voltage that's bad!

[Bfromla]

Testing amps not just static voltage. CCA ( Cold Cranking Amps) yet another diversity in battery size & functionality.

[K80Shooter]

As stated above, take it to just about any auto parts store and they will do it for free. Even most Wal-Marts do it if they do oil changes and tires.

[bluewoo]

Just make sure battery has been fully charged before testing.

[Revalden]

I think I saw a LOAD TESTER at Harbor Freight the other day for $19.95. I've had one for years and it works fine.

[Peter Aawen]

If you don't have access to a load tester immediately, then you can still do a rudimentary 'load test' using just a multi-meter.

You should always do this to a 'rested battery', not something that's just come off a charger or tender, or you might get false 'high readings' from the cover charge the recent charging/tendering has put in there; so wait about a half an hour or so after disconnecting the battery from any external chargers/tenders &/or after running the engine. Then set your multi-meter to the 0-20 volts range, connect it across the battery terminals, and take a reading - write it down. Next, while you watch the multi-meter to see what the charge drops to, get someone to start the engine. You need to see (& write down) the LOWEST voltage you see; and then look for & write down the voltage that the multi-meter settles on once the engine is running smoothly at idle. Finally, rev the engine up to about 3500 rpm and write down the (hopefully higher ) voltage that those revs produce.

If you've done this properly, you'll end up with Four (4) readings:

1. Resting Voltage;
2. Starting Voltage (under load, as the starter is cranking & before the engine fires);
3. Idling Voltage (alternator or magneto provided voltage @ idle); and
4. Charging voltage (alternator or magneto charge output voltage).

Because Spyder batteries are (usually) AGM batteries AND some of the Spyder's systems are extremely power hungry, if you don't have AT LEAST the following readings for each of these, you may well be having 'low battery' problems:

1. Resting.... = 12.5v (or more!);
2. Starting... = 12.0v (or more!);
3. Idling....... = 12.75v (or more!);
4. Charging. = 13.25v (or more, but not too much over 14.0v!)

Now some might feel the need to argue about the specific voltages I've put up there, but those I've provided above are derived from a reasonable amount of experience with SPYDERS and their power hungry systems, and while they may not be exactly what someone else considers right or what some internet chart provides, they are a good working guide where I've found that if you don't get AT LEAST those readings in this rudimentary multi-meter based 'load test', then you'll very likely be experiencing (or about to experience) 'low battery' issues (if voltages 1. or 2. are any lower) or charging system issues (if voltages 3. or 4. are any lower) with your Spyder. And please remember, this is a rudimentary test intended as a guide to help someone who doesn't have immediate access to a 'proper' load tester but who can access & use a basic multi-meter; and it's info provided in the hope that it might help some Spyder Ryders who may not be as fully up to speed on this sort of stuff as some others may be.

Over to you all. Good luck!

[ButterSmooth]

If you don't have access to a load tester immediately, then you can still do a rudimentary 'load test' using just a multi-meter.

You should always do this to a 'rested battery', not something that's just come off a charger or tender, or you might get false 'high readings' from the cover charge the recent charging/tendering has put in there; so wait about a half an hour or so after disconnecting the battery from any external chargers/tenders &/or after running the engine. Then set your multi-meter to the 0-20 volts range, connect it across the battery terminals, and take a reading - write it down. Next, while you watch the multi-meter to see what the charge drops to, get someone to start the engine. You need to see (& write down) the LOWEST voltage you see; and then look for & write down the voltage that the multi-meter settles on once the engine is running smoothly at idle. Finally, rev the engine up to about 3500 rpm and write down the (hopefully higher ) voltage that those revs produce.

If you've done this properly, you'll end up with Four (4) readings:

1. Resting Voltage;
2. Starting Voltage (under load, as the starter is cranking & before the engine fires);
3. Idling Voltage (alternator or magneto provided voltage @ idle); and
4. Charging voltage (alternator or magneto charge output voltage).

Because Spyder batteries are (usually) AGM batteries AND some of the Spyder's systems are extremely power hungry, if you don't have AT LEAST the following readings for each of these, you may well be having 'low battery' problems:

1. Resting.... = 12.5v (or more!);
2. Starting... = 12.0v (or more!);
3. Idling....... = 12.75v (or more!);
4. Charging. = 13.25v (or more, but not too much over 14.0v!)

Now some might feel the need to argue about the specific voltages I've put up there, but those I've provided above are derived from a reasonable amount of experience with SPYDERS and their power hungry systems, and while they may not be exactly what someone else considers right or what some internet chart provides, they are a good working guide where I've found that if you don't get AT LEAST those readings in this rudimentary multi-meter based 'load test', then you'll very likely be experiencing (or about to experience) 'low battery' issues (if voltages 1. or 2. are any lower) or charging system issues (if voltages 3. or 4. are any lower) with your Spyder. And please remember, this is a rudimentary test intended as a guide to help someone who doesn't have immediate access to a 'proper' load tester but who can access & use a basic multi-meter; and it's info provided in the hope that it might help some Spyder Ryders who may not be as fully up to speed on this sort of stuff as some others may be.

Over to you all. Good luck!

Such a nice, concise writeup that I clipped it out and added it to my Spyder maintenance note file. Here are the readings from my 2020RT that I took a while back, just in case there's trouble down the road:

Battery Voltage measurements:
Off, no key in ignition 12.82v
Off, ken in ignition 12.82v
Battery Load Test (Innova 3320) 12.7v
Cranking 11.28v
Charging 14.73v

[Hoginedgewood]

When the subject of failing batteries comes up, the question of load testing your battery comes up. How does a person load test their battery and what device or tool do you need to do so?
Thanks in advance,
Jim

Always make sure the battery is fully charged before load testing!
Always make sure the battery is fully charged before load testing!
Always make sure the battery is fully charged before load testing!

[Mikey]

If you don't have access to a load tester immediately, then you can still do a rudimentary 'load test' using just a multi-meter.

You should always do this to a 'rested battery', not something that's just come off a charger or tender, or you might get false 'high readings' from the cover charge the recent charging/tendering has put in there; so wait about a half an hour or so after disconnecting the battery from any external chargers/tenders &/or after running the engine. Then set your multi-meter to the 0-20 volts range, connect it across the battery terminals, and take a reading - write it down. Next, while you watch the multi-meter to see what the charge drops to, get someone to start the engine. You need to see (& write down) the LOWEST voltage you see; and then look for & write down the voltage that the multi-meter settles on once the engine is running smoothly at idle. Finally, rev the engine up to about 3500 rpm and write down the (hopefully higher ) voltage that those revs produce.

If you've done this properly, you'll end up with Four (4) readings:

1. Resting Voltage;
2. Starting Voltage (under load, as the starter is cranking & before the engine fires);
3. Idling Voltage (alternator or magneto provided voltage @ idle); and
4. Charging voltage (alternator or magneto charge output voltage).

Because Spyder batteries are (usually) AGM batteries AND some of the Spyder's systems are extremely power hungry, if you don't have AT LEAST the following readings for each of these, you may well be having 'low battery' problems:

1. Resting.... = 12.5v (or more!);
2. Starting... = 12.0v (or more!);
3. Idling....... = 12.75v (or more!);
4. Charging. = 13.25v (or more, but not too much over 14.0v!)

Now some might feel the need to argue about the specific voltages I've put up there, but those I've provided above are derived from a reasonable amount of experience with SPYDERS and their power hungry systems, and while they may not be exactly what someone else considers right or what some internet chart provides, they are a good working guide where I've found that if you don't get AT LEAST those readings in this rudimentary multi-meter based 'load test', then you'll very likely be experiencing (or about to experience) 'low battery' issues (if voltages 1. or 2. are any lower) or charging system issues (if voltages 3. or 4. are any lower) with your Spyder. And please remember, this is a rudimentary test intended as a guide to help someone who doesn't have immediate access to a 'proper' load tester but who can access & use a basic multi-meter; and it's info provided in the hope that it might help some Spyder Ryders who may not be as fully up to speed on this sort of stuff as some others may be.

Over to you all. Good luck!

I knew you'd come threw Peter!!!!

[JimH]

If you don't have access to a load tester immediately, then you can still do a rudimentary 'load test' using just a multi-meter.

You should always do this to a 'rested battery', not something that's just come off a charger or tender, or you might get false 'high readings' from the cover charge the recent charging/tendering has put in there; so wait about a half an hour or so after disconnecting the battery from any external chargers/tenders &/or after running the engine. Then set your multi-meter to the 0-20 volts range, connect it across the battery terminals, and take a reading - write it down. Next, while you watch the multi-meter to see what the charge drops to, get someone to start the engine. You need to see (& write down) the LOWEST voltage you see; and then look for & write down the voltage that the multi-meter settles on once the engine is running smoothly at idle. Finally, rev the engine up to about 3500 rpm and write down the (hopefully higher ) voltage that those revs produce.

If you've done this properly, you'll end up with Four (4) readings:

1. Resting Voltage;
2. Starting Voltage (under load, as the starter is cranking & before the engine fires);
3. Idling Voltage (alternator or magneto provided voltage @ idle); and
4. Charging voltage (alternator or magneto charge output voltage).

Because Spyder batteries are (usually) AGM batteries AND some of the Spyder's systems are extremely power hungry, if you don't have AT LEAST the following readings for each of these, you may well be having 'low battery' problems:

1. Resting.... = 12.5v (or more!);
2. Starting... = 12.0v (or more!);
3. Idling....... = 12.75v (or more!);
4. Charging. = 13.25v (or more, but not too much over 14.0v!)

Now some might feel the need to argue about the specific voltages I've put up there, but those I've provided above are derived from a reasonable amount of experience with SPYDERS and their power hungry systems, and while they may not be exactly what someone else considers right or what some internet chart provides, they are a good working guide where I've found that if you don't get AT LEAST those readings in this rudimentary multi-meter based 'load test', then you'll very likely be experiencing (or about to experience) 'low battery' issues (if voltages 1. or 2. are any lower) or charging system issues (if voltages 3. or 4. are any lower) with your Spyder. And please remember, this is a rudimentary test intended as a guide to help someone who doesn't have immediate access to a 'proper' load tester but who can access & use a basic multi-meter; and it's info provided in the hope that it might help some Spyder Ryders who may not be as fully up to speed on this sort of stuff as some others may be.

Over to you all. Good luck!

Thanks for the details Pete - you'll make a motorhead out of me yet. . I appreciate the information.

[wingit3611]

These readings are with a Digital meter. Not an old darsinval (clock spring) meter.

[gkamer]

When the subject of failing batteries comes up, the question of load testing your battery comes up. How does a person load test their battery and what device or tool do you need to do so?
Thanks in advance,
Jim

I took my ride to NAPA and they tested it for me, no charge. I think most any auto parts place will like Auto Zone or O'Reily.

[IdahoMtnSpyder]

A "poor man's way" to load test the battery is this. Connect a voltmeter to the battery. Hold the throttle wide open. This keeps the engine from starting. Push the starter button and hold it for several seconds. If the voltage drops quickly to near 10.5 then the battery is questionable. If the voltage drops slowly then the battery is good. Don't crank the engine for more than about 10 or 15 seconds without pausing or the starter may get hot.