Alternator

[hubcapsc]

There's lots of Alternator threads...

My bike almost didn't start last Saturday, I thought it was going to let me down, but then
it fired up. It was kind of cold out, but I have easily cranked it cold many times.

Today, one week later, I've got a multimeter on hand.

Tested the battery with the bike off: 12.5

Fired the bike up (it fired right up as normal) and revved it a little: 13.7

Now I'm inside reading the manual, it sez:

  fully charged: 13.0 - 13.2
under charged: Below 12.3

Then, to test charging, run the bike to operating temp (I didn't do that)
and then with the high beams on at 5,000 rpm (I probably didn't rev it that high):

measured battery voltage (12.5 for me) < Measured charging voltage (13.7 for me) < 15.5

Maybe I'll go ride it around the block and test it heated up and then come back here and
see if y'all have said anything...

-Mike

[eric in md]

batterys are such junk anymore might have a dead cell .. 

[BonS]

Had the bike been sitting around for a while when you had trouble starting? I figure it may have as I know you have an alternate ride. Perhaps the battery is simply getting old and self-discharged from sitting.

I take it that your battery voltage readings were taken after riding for awhile or after putting a charge on the battery? If it had 12.5 volts and struggled to start you bike then the battery is either dry (is it a vented wet cell?) or old and has a lot of internal resistance from a bad cell(s).

The measured standing battery voltage is fine. The charging voltage (not knowing the rpm's) is about right if not just a little bit low. I'd expect to see about 14.25 volts at 2k rpm on low beam (Interstate).

[hubcapsc]

Had the bike been sitting around for a while when you had trouble starting?

Not too long, but some... maybe even a couple of weeks.

Perhaps the battery is simply getting old and self-discharged from sitting.

I would guess that I wrote down when I bought the battery... I'll have to go out and
look... it is just a couple of years old, a USA made Yuasa...

I take it that your battery voltage readings were taken after riding for awhile or after putting a charge on the battery?

Nope... I hadn't touched the bike since I started it last week, and then I only started it to move it
from the shed so I could change its tires.

The measured standing battery voltage is fine. The charging voltage (not knowing the rpm's) is about right if not just a little bit low. I'd expect to see about 14.25 volts at 2k rpm on low beam (Interstate).


Yeah, the one time that it didn't start right up like usual, and the lower-than-I expected-reading
while it was running has me unsettled... I don't want to be the guy whose bike breaks while
out on the road with a group and I don't want to change the alternator unnecessarily...

-Mike

[BonS]

Well, as always, check your connections to the battery and possibly the starter switch itself. You know, the easy, free, stuff. Old batteries and cold weather, it brings out the worst.

A battery that sits around at 12.5 volts is doing what it should. A big test is after it's fully charged and put under load such as starting. The voltage, at the battery, should stay above 11 volts. When you just turn on your ignition and the lights are on you should see the voltage steadily decaying but start to hold firm around 12.25 volts for sure. Cold, freezing weather reduces the measured voltages.

Finally, most auto part stores will load test your battery on the bike to determine its overall condition.

[hubcapsc]

I went down to Advance Auto parts with my battery today.

I wonder if their little machine actually does anything other than make printouts like this?



Whatever. Anywho... check this out... it's like an empty plastic box,
I think it would float!



It is a lot smaller than a normal battery, it comes with little legs to prop it up
in the battery box...



There's a little test button on it to show it's state of charge...

The multimeter says it has a 13 volt charge now. When the bike is
cranked, it still only shows 13.6 or so... I'll just use it and watch it,
keep the multimeter in the saddlebag...

-Mike

[BonS]

Interesting, Mike. Cool new battery you have there. And at no extra cost you get extra storage space. Yeah, it's beneath your battery but as an I/S owner with CB, trailer, XM, aux fuse panel and intercom under the seat every cubic inch of internal space is extremely valuable.

I don't see why the battery tester gave you a failing grade. The YTZX14L-BS is rated at 200 CCA and yours put out 237. That's a harsh mistress and self serving at that.

From time to time I test batteries for fire suppression purposes. The video is a battery fire of a Lithium battery that is at 50% charge. A 100% charge battery fire is much closer to an explosion where the fire ball and pressure is much, much greater. The thermal runaway temperature of a Lithium cell is around 235 degrees Fahrenheit. You certainly never want to overcharge one of these. The battery in the video was heated slowly with a hot plate.

LiPo Auto Ignition Test 1	powered by Aeva

[hubcapsc]

You certainly never want to overcharge one of these.

No worries about that with my alternator's output 

-Mike 

[gordonv]

Interesting, Mike. Cool new battery you have there. And at no extra cost you get extra storage space. Yeah, it's beneath your battery but as an I/S owner with CB, trailer, XM, aux fuse panel and intercom under the seat every cubic inch of internal space is extremely valuable.

I don't see why the battery tester gave you a failing grade. The YTZX14L-BS is rated at 200 CCA and yours put out 237. That's a harsh mistress and self serving at that.

From time to time I test batteries for fire suppression purposes. The video is a battery fire of a Lithium battery that is at 50% charge. A 100% charge battery fire is much closer to an explosion where the fire ball and pressure is much, much greater. The thermal runaway temperature of a Lithium cell is around 235 degrees Fahrenheit. You certainly never want to overcharge one of these. The battery in the video was heated slowly with a hot plate.

http://youtu.be/Rt1iwwZV8N8

Is this the kind of thing (sorry for the change in thread) that is the reason why they don't want them on air planes?

[BonS]

Exactly. But it's not just the fire and smoke. It's the Hydrogen Fluoride gas that's created. It's deadly when breathed and it's absorbed through the skin and goes right into your bones. Ugh!