Testing Bike Batteries with Automotive Tester

[TinyTrains]

I received a 130A automotive battery tester for X-mas. It works fine on my car batteries, but can it be used on BMW bike batteries? 130A for 10 seconds seems like a lot for a small battery.

Thanks,
Scott

[dbrick]

What do the specifications or instructions say?

[TinyTrains]

What do the specifications or instructions say?

It says nothing about battery size.

Instructions:
Connect to battery.
Push button 10 seconds (130 Amps).
If needle is in the green (11volts), the battery is good.

[MANICMECHANIC]

The purpose of the load tester (which it sounds like you have) is to simulate a large load, such as a starter motor. You can then determine if the battery can recover sufficiently or not.

[TinyTrains]

Let me rephrase the question:

What is the normal load-test current for 12 AH motorcycle batteries?

The battery is rated at 200 Cold Cranking Amps.

Thanks,
Scott

[PGlaves]

So, the battery can put out 200 amps max, and the tester will draw 130 amps for a load test. It appears to me it is suitable but maybe one of our automotive or electrical engineers can pipe in here.

[dbrick]

Scott,

I found this manual for a Harbor Freight load tester: http://manuals.harborfreight.com/man...1999/91129.pdf
in a discussion of load-testing a bike battery. Step 4 under "Testing the Battery" directs the user to increase the load (it's variable) to a level one-half of the battery's CCA rating or three times the battery's amp-hour capacity, to hold that load for fifteen seconds, then read the battery's condition on the meter. So this tester's designer thinks that either of those are the load and duration.

120 amps does look too big: if your airhead has the big 25 a/h battery, the test current under this set of instructions' rule of thumb would be be 75 amps, not 120. Is your unit adjustable?

[TinyTrains]

The battery is for an R1200R, so it is 12AH, with 200CCA. I have sent an email to Yuasa and will see what they say.

Thanks

[pffog]

Been 20 years, but what I remember was 3 times the rated capacity, so 36 amps for a 12 ah battery.

[milo]

..... 130A for 10 seconds seems like a lot for a small battery.

It does to me also. I received a Yuasa BTY01 Powersports Battery Tester for Xmas. You must input the battery AH to the tester before beginning the test. So it must be important for the tester to "know" the size of the battery it's testing.

[pffog]

After answering the original question, I had to sit back and ask why bother. Load testing just confirms what you should already know, the battery is getting weak, the bike cranks slow, of barely cranks after sitting for a few days.

It will not ferret out a sudden catastrophic failure that frequently occurs, it will not tell you there is only a month or two left. Every battery failures are different, I have had "weak" batteries stay that way for a year, I have had new batteries suddenly fail, I have had strong batteries instantly turn weak, etc. If all failures were linear than yes it would be a guide, but lead acid batteries for the most part have no rhyme or reason to failing.

[RINTY]

Calling Global Rider....

[tommcgee]

Easier test:

1. Wait five years.
2. Replace battery.

[GlobalRider]

Let me rephrase the question:

What is the normal load-test current for 12 AH motorcycle batteries?

The battery is rated at 200 Cold Cranking Amps.

A load test is normally performed at 1/2 the CCA with the voltage not dropping below a certain level during the 15 second test.

I have seen various minimum voltage levels used for the test. Of course, the higher the voltage maintained, the tougher the test.

The test should be performed on a fully charged battery.

Here is a handy Battery Testing Chart. Note the CCA test on page 2.

When a battery's internal resistance increases (a bad thing), they fail a load test sooner or later.

[GlobalRider]

Calling Global Rider....

Sorry, was busy making Beru ignition cables for 993s.

Damn cold here and that 14 year old battery of mine turned my car's motor over like a new battery.