Test Starter and Battery

[Kiwi_Roy]

Here is a simple way to prove out the starter, battery and the main high current wiring.
Take a wire with spade connector and connect it to the spade lug on the solenoid, don't turn the key on (unless you need it to start)
touch the other end of the wire to battery positive. This will bypass all the bikes secondary wiring to pull the solenoid in and energize the starter.
If the bike cranks over you have eliminated the battery, starter and all the main connections.
If it fails to crank of course you have other problems.
If you have a Voltmeter across the battery you will read around 10 Volts while cranking.
CAUTION, make sure you are in neutral or it could launch, pull the clutch in for extra safety.
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This is the method I use when doing a compression test, it spins the engine over without adding fuel or spark, as the key is off the coils, pump and injectors are not operating.
Of course if its a bike with carbs you still get fuel because you have the throttle wide open.
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The other day a local store had digital battery load testers on sale so I picked one up, this puts a load of 125 Amps on the battery and allows you to enter the Cold Cranking Amps from 200 to 1,000 Amps
I found all my bike batteries would pass on the 200 range but not 300, the default is 500 Amps for a car battery. Of course a bike battery will fail if you forget to change the CCA setting but no harm done.
It doesn't actually change the current when you set CCA but it uses the number in a calculation to assess the health.

[Wayne Orwig]

I just ordered a cheap load tester. 100 amps with an analog meter. What one did you get.

I have always gotten by with a meter and the starter motor. But I have two RV batteries that are questionable, and no good way to load test them. So this $25 one should help.

[Tom H]

I had an auto parts store load test my truck battery in their machine. They said the battery was fine, I do not need a new one. Bought a new battery anyways, problem solved. The battery was not holding a charge. The battery had one of the bubbles that showed the state of charge. When new it was green. When I was having issues, it was black even when my charger said it was full. It never did show red, don't know why.

Load test may not always show a bad battery.

Tom

[Kiwi_Roy]

I just ordered a cheap load tester. 100 amps with an analog meter. What one did you get.

I have always gotten by with a meter and the starter motor. But I have two RV batteries that are questionable, and no good way to load test them. So this $25 one should help.

Me too, I always thought I would make a load tester but this offers seemed to good to turn down.
Its a cheap digital one, I was torn between this and an analog for similar money.
According to the manual it loads the battery with 125 Amps, I will check that one day.
The second picture show the Voltage reading before test.
3rd and 4th show setting the CCA, 200 seems ideal for a bike battery.
Last picture shows Voltage under load.
 
It has a relay that closes to add the load when you press Test-Start, it stays closed for 10 seconds, do it several times and you will see the load resistor glowing red hot.
If nothing else its a good load resistor.
I will be interested to see how you find the analog version.

[Brian UK]

Interesting, hadn't realised they were that cheap.

[n3303j]

I just ordered a cheap load tester. 100 amps with an analog meter. What one did you get.

I have always gotten by with a meter and the starter motor. But I have two RV batteries that are questionable, and no good way to load test them. So this $25 one should help.

A proper "house" battery for an RV is a deep cycle design and is not designed for handling engine starting loads. An economy auto load tester will subject the battery to a load beyond its output rating and still not give you a true picture of the battery capability.

You'd do better to hook the battery up to a pair of headlamps, measure their current draw and see how long it took to run the battery down to minimum levels. Then you would have a true amp hour capacity figure for the battery in question.