Battery

[rxcrider]

I use one of these



http://www.grainger.com/Grainger/OTC...GV7?Pid=search

Not the greatest in the world, but it works well enough for my purposes.

[naddy100]

I use one of these

Very cool. I notice that their battery testers ranged from 100 amps to 200 amps, with corresponding differences in price.

Noel

[98lee]

You could go with this for $10, if you just want to use it just for your bikes:
http://www.harborfreight.com/50-amp-...ter-93784.html


But I would recommend this one for $20 that would also work well for your cars:
http://www.harborfreight.com/100-amp...ter-90636.html

[PGlaves]

I tried the pump first. Bigger load. It wouldn't do anything. Then tried the light bulb because it was in fact so puny. I also tried a 2.5 amp MR16 bulb which when attached dropped the measured voltage to less than one volt. An H4 high beam at about 4.3 amps pulled it down to something approximating .1 volt.

Lacking a real load tester these different loads were sufficient to tell me in certain terms that the battery was headed to the recycler. But I just found it weird that the difference between the standing no load voltage and the .5 amp load voltage was so striking. I have had broken connectors or similar inside batteries before where the thing actually went open between the two posts - ie - I got no voltage reading whatsoever. This I understand. But the 12.7 down to 4 with minimal load is what I wanted to understand.

[larrysb]

Until you cobble one up, or purchase one, your light bulb isn't such a terrible idea. Me? I'd go for something that consumes higher current, like a sealed beam headlight lamp.

I use one out of the pile of headlights in my garage that were changed due rock chips and BB-pit-holes in the glass over the years.

The filaments are not as themistor-like as people imagine.

[larrysb]

Until you cobble one up, or purchase one, your light bulb isn't such a terrible idea. Me? I'd go for something that consumes higher current, like a sealed beam headlight lamp.

I use one out of the pile of headlights in my garage that were changed due rock chips and BB-pit-holes in the glass over the years.

The filaments are not as themistor-like as people imagine.

[GlobalRider]

The lesson is that you certainly need to test more than the no-load voltage if you think you have a battery problem.

Well of course.

A complete battery test consists of a load test and a capacity test.

Even those "conductance" testers do not provide the whole story. I've connected them to batteries only to have them indicate a healthy CCA, battery voltage and even a "Good Battery" indication...this from a 100 Ah battery that only has 25 Ah of capacity.

[GlobalRider]

Followup comments: The battery was branded Scorpion, model YT12CL, sealed AGM type.

That may be your problem, Paul.

Do you use this battery in Texas? Have you checked the battery voltage under various conditions when it is 100F outside? Chances are you are overcharging the battery and it is now dry. Now you know why I mounted a voltmeter on my GS and Porsche which is wired directly to the battery.

That is the problem with VRLA batteries; AGM or GEL. You can't afford to have them gas due to overcharging because what is lost cannot be replenished...as in being able to add distilled water as you can in a flooded lead acid battery.

Another fact about battery life, ever 8C (15F) increase above 27C (80F) decreases battery life in half. Run a battery in 110F temperatures and it lasts 1/4 as long as it does at 80F. Vibration is the other battery killer.

BTW, invest in a carbon pile 500A load tester from Harbor Freight. A load test is done at 1/2 the CCA rating of the battery for 15 seconds with voltage decreasing no lower than 10.5V...this test is done on a fully charged battery.

[GlobalRider]

Paul, the following chart shows battery charge and float voltages based on battery temperature.

As you can see, you hope your voltage regulator temperature compensates. An on-board voltmeter will tell you that.

[t6pilot]

car's and bikes i change every three years, do not want to get stranded. that being said my airplane lives with a seven year old battery it gets a 30 minute charge every day. play it safe..

[MOTORRADMIKE]

car's and bikes i change every three years, do not want to get stranded. that being said my airplane lives with a seven year old battery it gets a 30 minute charge every day. play it safe..

That seems a bit backwards.

Thanks for the chart Alex.

[PGlaves]

That may be your problem, Paul.

Do you use this battery in Texas? Have you checked the battery voltage under various conditions when it is 100F outside? Chances are you are overcharging the battery and it is now dry. Now you know why I mounted a voltmeter on my GS and Porsche which is wired directly to the battery.

I bought the bike in November. I don't know what it did in its former life but the battery hasn't seen anything close to 100 degrees over the winter. It is not the first battery that has failed on us, and the failure wasn't totally unexpected. I do have a volt meter on the bike - full time. And I know that the cheesy charging system on F650s over cooks batteries.

What puzzled me was the failure mode. I've had the dread Yuasa snap-pop dead zero volts. I've had the slow but sure loss of capacity. But I have never had one act quite like this one did - described in posts above. I was trying to figure out the failure mode is all.

[GlobalRider]

Thanks for the chart Alex.

Mike, here is a chart for GEL batteries, or better yet, its all in the East Penn Technical Manual. Note pages 9, 11 and 12.

[GlobalRider]

And I know that the cheesy charging system on F650s over cooks batteries.

If you remember, what kind of voltages are you getting during cruise RPM and at what ambient temperatures?

Does it follow the charts or is the voltage quite a bit higher?

[GlobalRider]

What puzzled me was the failure mode.

My diagnosis is that the battery failed, suddenly and totally. Yet it still showed a standing no load voltage of 12.7 volts. But it had virtually no capacity to power anything. It wouldn't power a tail light bulb, let alone a starter.

I wonder how it was a day before or a week before.

I suspect high internal resistance....all of a sudden?