Testing bike with different battery

spray____

spray____

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Going to check out a bike today and the owner says it has a dead battery.

My plan is to take along my existing battery (which is on charge for the winter) so I can throw it in the bike and test it. However, my bike isn't the same as the one I'm looking at so the battery is obviously different as well.

Right now my assumption is the differences don't matter since they are only:
  • Cold cranking amps (of the batteries I've looked at online, mine has more so should be fine)
  • Amp Hours (mine has more so should be fine)
  • Physical size (this isn't permanent so should be fine to test with)

I really just want to throw it in to see the bike runs and check the electrical system.

Is there anything else I'm not thinking of, or a reason I shouldn't do this? Will this affect the electrical system in any way while I'm looking at it? Would it be better just to jump the bike with a car battery?
 
Should be fine
 
As long as they are both 12 volt systems, it will be fine. You will only find 6 volt systems on very, very ancient vehicles. For testing, just hook up the corresponding terminals with jumper cables; you could even do it from your (not running) car.
 
I would use your car battery and disconnect it once it's running fine. this way you can see if the alternator is good or needs to be replaced. Or you can bring a DMM and test the voltage
 
Awesome, thanks for the confirmation. Sounds like I've got a plan that will work. I've got cables, a 12v motorcycle battery, and my car so should be able to figure it out. I'm going to bring a Digital Multimeter and check the charging system too.
 
Jimsun said:
I would use your car battery and disconnect it once it's running fine. this way you can see if the alternator is good or needs to be replaced. Or you can bring a DMM and test the voltage
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No... this is way you test if you can blow the ECU.

NEVER disconnect the battery cables of a modern running motor. That was a valid test when cars had mechanical regulators and generators.
When you pull the cable, the voltage regulator loses it's reference to ground, which may cause a voltage spike... taking out everything electronic on the vehicle.

For the OP: You'll be fine. The bike won't know the difference.
As mentioned, I would just boost it off my car.
 
bitzz said:
No... this is way you test if you can blow the ECU.

NEVER disconnect the battery cables of a modern running motor. That was a valid test when cars had mechanical regulators and generators.
When you pull the cable, the voltage regulator loses it's reference to ground, which may cause a voltage spike... taking out everything electronic on the vehicle.

For the OP: You'll be fine. The bike won't know the difference.
As mentioned, I would just boost it off my car.
Click to expand...

Would you boost it off you car while your car was idling/engine running?
 
Pretty sure he just meant removing the jumper cables and putting a meter on the battery to check the charging voltage.
 
dricked said:
Pretty sure he just meant removing the jumper cables and putting a meter on the battery to check the charging voltage.
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There is no reason to remove the boost cables.
When the bike starts, AND the alternator works: the voltage across the battery WILL rise.

The car can be running or not, it doesn't matter. You are NOT going to get more power out of the boost with the car running.
 
bitzz said:
No... this is way you test if you can blow the ECU.

NEVER disconnect the battery cables of a modern running motor. That was a valid test when cars had mechanical regulators and generators.
When you pull the cable, the voltage regulator loses it's reference to ground, which may cause a voltage spike... taking out everything electronic on the vehicle.

For the OP: You'll be fine. The bike won't know the difference.
As mentioned, I would just boost it off my car.
Click to expand...

You motor wont get messed up if u remove a cable of a modern motor. Just remove the positive cable not the negative/ground and your electronic is protected via fuse.

If you think this is unsafe, just use a meter. Problem solved.
 
I would use another motorcycle battery. That way, when the bike starts you can measure voltage at the battery and see if the charging system on the bike is functioning properly. A fully charged battery is about 12.7 volts. When the bike starts, you should have at least 13.5 volts measured with a voltmeter at the battery terminals with the engine running. If not, then there's a reason the original battery is dead.
 
There is no any issue to test bike with different battery if they are same with voltage. I have tried this many time and it is fine.
 
Only problem with using a car batt is an uninformed owner. Take the bike batt, just to have a smoother interaction.
 
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