Cold Battery Question.

[JeffD]

Alright well this morning was a little bit cold (45 degrees outside) and I get ready to go to school.  I turn on the choke, and try to start the bike.  And I try again, And again, and again until the bike wont turn over any more, thus the battery was now dead...or so I thought.  I never got it started so I got a ride to school.  After school (5pm) I went to walmart and picked up a ES12BS, thinking I could just change the battery and not futs with it anymore.  So we get home and just for the hell of it I got on my bike and it started first try. WTF?!?  I didn't do anything to it,  the only difference is the fact that 1. it had sat all day, and 2. it was warmer outside.

So my thinking is that either I have dirty connections on the terminals, and when it gets cold the dirt wont let enough current go through to start the bike, OR the battery is BAD.    I just spent $60 on this freaking battery and I dont want to use it if I dont have to.  

Any insight appreciated.  Thanks.

[Cal Price]

Last winter I had two occasions with the wild blue Honda when all the electrics failed to respond, apparently no power. Both occasions were sub-zero (just) On both occasions the problem seemed to correct itself, I was not able to find any faults and the battery checked out fine once it was warmer. I think it's a charecteristic of batteries that they are affected by temperature. it's time like that when you realise what a good idea a kick-start is. The temp you mention should not have that effect but it is possible that it's on the way out and perhaps your cash was not wasted.

[Rema1000]

Two problems conspiring against you, Jeff.  

The amps the battery can crank-out drop quite a bit with the temperature; you gained more cranking amps from that 10 degrees warmup than you lost from trying unsuccessfully to start.  One tip: put a little load on the battery, and it will warm itself up.  To check this out, go out when it's cold with a multimeter on the battery.  Start the headlights:  the voltage under load will drop... then slowly increase as the battery warms up.  A battery can pull itself up by its bootstraps by warming itself, and making even more amperage available for turning the starter... or so I've heard.  I guess if I were serious about it, I'd put some resisive/thermal wire around the battery in the battery box, and make a "hot pad" that I could run for a few minutes before trying to start.

The other thing is that a battery can drop from 12.5v down to 10v or so through repeated cranking, until the motor won't even turn-over anymore... but let it sit for an hour and it's right back up to 12+v.  One tip: shaking the bike can help accelerate the recovery, if you're desperate, and have nothing to do for 15 minutes .

[vtlion]

ooh... ooh... somebody's gotta bust out the Nernst equation....

I know 'T' is in there somewhere....  :mrgreen:

E = RT/nF * ln(Q)

dE=(R(dT))/(nF) * ln(Q)  

assuming freezing vs standard temperature...

dE is proportional to dT = 298k-(~273K) = -25K ... about -10%

jeeze, I hate electrochemistry...

Of course, that's just potential.  Current is whole other ball of wax... and probably the issue (as JeffD has already hypothesized).  I've been able to turn mine over alot colder than that, but around freezing my battery (new this year) really struggles to turn over.

Rema1000, that's some really insightful stuff about the battery warming itself.. I never would have thought of that.   I wonder, is there anything that can be done safely to help out with cold starts?  Besides bump-starting and taking the battery inside after every ride, of course.  Can that recovery phenomenon that you mentioned be used to start a cold bike that's being cranky?  I really want to go hard-core and ride all year, but here in PA, its gonna get alot colder than freezing soon and I'm worried about getting stuck with a bike that won't turn over.

good luck with your troubleshooting JeffD.

[rideLIKEjehu]

time to practice up on those bump-starts, eh?

[KevinC]

Stick it on a Battery Tender when it's parked at home. Not only does it keep it charged, but the current keeps it warmer too.

Motorcycle batteries are crap basically. Get one of the new, expensive sealed type. They work better in the cold.

In Canada, battery warmers are readily available. They are AC powered though. Turning on the lights awhile to warm the battery before trying to crank the engine is a standard trick. Turn the lights off for 30 seconds before trying to crank.

Oh, and kickstarting a cold bike was no joy either. I remember the worst time I had was coming back to Vancouver in January from Mexico with straight 50 weight oil in my Norton. On a cold morning in Washington state somewhere, I could stand on the kicksarter, and it would slowly go down over about 15 seconds.

[cozy]

Add to all that physics stuff that all batteries cca (cold cranking amps - cold in this case having nothing to do with atmospheric temperature) are rated at 70 degrees F. So what ever a battery says it'll do on the label it'll do when conditions are perfect.

[Yohan]

It's the snow gnome playing tricks on you.  

[Rema1000]

I wonder, is there anything that can be done safely to help out with cold starts?  Besides bump-starting and taking the battery inside after every ride, of course.  Can that recovery phenomenon that you mentioned be used to start a cold bike that's being cranky?

The "recovery" period will only help _after_ you've tried (and failed) to start.  Per Yuasa's web site:

Since the current is produced by the chemical reaction at the surface of the plates, a heavy current flow will quickly reduce the electrolyte on the surface of the plates to water. The voltage and current will be reduced to a level insufficient to operate the starter. It takes time for more acid to diffuse through the electrolyte and get to the plates' surface. A short rest period accomplishes this.

...so if you fail to start, don't give up!  Just come back later and try again.

As far as general things:

-Get the new Battery Tender Junior waterproof and mount it semi-permanently under the seat: would let you plug in and charge (at 750mA) anywhere with a 110v plug.

-Carry some 12ga. braided wire to use as jumper cable.  Mark the ends of one with red tape.  Then you can start anywhere there's a car and an accomodating driver.  Turn the car off before connecting.

-Park in a parking ramp, or at least out of the wind.  If your business has an exposed parking lot, they may still have a garbage enclosure, which can help.  Anything which slows the wind blowing through the bike will slow the cooling of the engine and battery, and will help.  An insulating sock around the battery would help, as would a bike cover.  Heck, do all three.

-The headlight trick helps, but I can't help but think how the 55 watts of headlight energy are being wasted, and would better be used to head the battery directly.

Crazy stuff you'd only consider because your battery is on its last legs and you are too cheap to  buy a new one :

-If your commute is too slow or too short to charge the battery (traffic, weather, city streets, etc.), then you can use a booster or a car battery to start in the morning.  That way, you've got better charge to start when you get ready to head home.

-Carry the booster on the back of your bike, so you can start it when you get done with dinner at the in-laws (I did say I was cheap, right?)

-Carry a gas can in your tailbag so you can go to the gas station and get gas without shutting-off the bike (OK, I know, that's too cheap for words)

-A can of starting fluid (ether) should help, but go easy on 'er!  You can blow things up that way .  It would be interesting to have a small cartridge of ether mounted in the airbox:  push a pin on the side of the airbox to give a squirt, wait 5 or 10 seconds, then try to start.  This is especially useful if your spark is weak while cranking.  I've had this happen to me, where the bike cranks several times, but won't catch, then the moment I let go of the starter, it fires and catches... vroom:  I think it's weak spark during cranking.

Just remember, it could be worse: a World War II field guide had instructions for how to build a charcoal fire under the fuel tank on the diesel trucks to keep them from gelling overnight!