Looking for a UPS Design That Doesn't Overheat Batteries

In article , repatch wrote:

On Mon, 05 Jun 2006 04:39:26 +0000, Don Klipstein wrote:
In article , repatch wrote: On Sun, 04 Jun 2006 09:18:24 -0400, Jerry Avins wrote:
Floyd L. Davidson wrote:
nicksanspam@ece.villanova.edu wrote:
Roy L. Fuchs wrote:
Shorting them actually uses up what charge is available and doesn't warm the battery enough to make it crank harder.
It is total myth.
Untrue. Take a look at some capacity vs temp curves. Warming a fully-charged cold battery can increase the available capacity, releasing more than the energy used to warm it.
Wrong. Read what he wrote: "doesn't warm the battery enough". That is true. Long before you get the battery warmer, you make it deader!
Besides, shorting a battery to warm it is about the stupidest thing I've ever heard of for other reasons, not the least of which is the potential for an explosion that will make you really really really ugly.
If it works, don't knock it. The attitude, "If I can't explain it, I can't believe it" is more than a bit silly, don't you think?
I agree, and I'm not going to comment on whether it works or not.
That said, I would NEVER do such a thing. It's dangerous for numerous reasons (big sparks under a hood are never good, grease can burn quite easily).
I hope you would have found a better example...
In my personal experience? No. I have on the other hand HAD a fire under the hood due to the grease/residue on the engine catching. Fortunately there wasn't much and it burned itself out very quickly, but had there been more it would have been a very bad day for me.
It doesn't matter if my example isn't "good enough", big sparks under the hood of a car are NEVER a good idea. The possibility of a small gasoline leak would be reason enough to never attempt such a thing.
Heck, consider that by doing this the pair of pliers weld themselves onto the connections, a car battery pumping hundreds if not thousands of amps through a pair of pliers uncontrolled would cause me to run.

And with that much current available, I would expect a car to start before its driver resorts to the desperation tactics under debate here!
- Don Klipstein (don@misty.com)

On Mon, 05 Jun 2006 01:18:07 -0400, repatch Gave us:

On Mon, 05 Jun 2006 04:19:55 +0000, no one that you know wrote:
Trus me when it's minus forty it takes more than a few seconds to cook a starter.........but thank you for your concern
I'm not exactly disagreeing with you (cranking for more then 10 seconds would concern me if you didn't give the starter a break between tries), but the op was talking about a STALLED starter. Whether or not this is good for the starter I don't know, what I do know is it's pretty pointless since a stalled starter has no chance of starting the engine, and you're simply wasting energy by doing so.
TTYL

But... but... but... he was warming up his battery!
Hahahahaha!

On Mon, 5 Jun 2006 05:21:06 +0000 (UTC), don@manx.misty.com (Don Klipstein) Gave us:

I would take a chance at

Your crap is not even worth answering.
Dead shorting a -40 battery or even a zero F battery is NOT going to "warm it" enough to make a subsequent short pass more current.
GET A CLUE!

On Mon, 5 Jun 2006 05:35:36 +0000 (UTC), don@manx.misty.com (Don Klipstein) Gave us:

Info relevant to here is lacking, although it does give fair chance that this could be someone other than the one of junior-highschool mentality that looked good mainly when his opponent was the infratroll sufficiently famous to get his own FAQ!
I hope you disclaim to be either of these offenders!

Can you be any more retarded today?

On Mon, 5 Jun 2006 05:38:08 +0000 (UTC), don@manx.misty.com (Don Klipstein) Gave us:

In article , Roy L. Fuchs wrote: On 4 Jun 2006 06:58:05 -0400, nick@acadia.ece.villanova.edu (Nick Pine) Gave us:
In article , Floyd L. Davidson wrote: nicksanspam@ece.villanova.edu wrote: no one that you know wrote:
why would you waste that current as heat in a set of pliers when all you have to do is crank it for a few sec and warm your frozen starter up as well
Because the pliers put more heat into the battery, and the starter works better when cold.
Wanna bet money on that?
No. I'm sure about the first, and cold copper wire conducts more current,
No, it does not. A SUPERCOOLED copper wire MAY be less resistive, but for ALL intents and purposes, we get the same wire in arctic conditions that we get in a desert swill. As far as it taking more current, it will heat up to the fuse point at MAYBE a slightly higher current due to a lower starting ambient, but the reason isn't because it conducts better.
Ever hear of copper's resistance being fairly close to proportional to absolute temperature?

Ever hear of current heating a conductor? The ABSOLUTE temperature of the wire will be VERY HIGH once it begins passing current. So much so that it negates any claim of the experiment's setting being different.
In other words... NO, one does NOT get a benefit from cold weather at the starter motor. The wires HEAT UP practically immediately.
You do know what the word HEAT means, right?

On Mon, 5 Jun 2006 05:42:13 +0000 (UTC), don@manx.misty.com (Don Klipstein) Gave us:

In article , Roy L. Fuchs wrote: On 4 Jun 2006 13:01:27 -0400, nicksanspam@ece.villanova.edu Gave us:
Roy L. Fuchs wrote:
... the pliers put more heat into the battery, and the starter works better when cold.
Wanna bet money on that?
No. I'm sure about the first, and cold copper wire conducts more current,
No, it does not...
It does indeed, with a positive copper tempco:
RHOt = 1.8x10^-8(1+0.0039(T-20) ohm-meters at T(C).
Yet you forget that the WIRE itself, not the ambient room temp has to be maintained at said temperature, and THAT is the part that does NOT happen.
but maybe cold bearings have more friction.
The bearings do not, but any greases on them are like putty.
Cold bearings probably have less friction.
You're an idiot to believe that. A DRY cold bearing MAY have greater clearances, but slop can cause friction problems elsewhere. If it is NOT a dry bearing, the grease used in it will most assuredly be less mobile when cold.
Most cold things shrink,
So what? The bearing race would shrink as well.
so tolerances would increase.
A ball bearing is hardened steel, and it will NOT shrink significantly in this scenario... at all.
Warming engine oil helps, but that's a different story.
Grease is a petroleum distillate in most cases as well. even synthetics thicken when cold.
Try again.
Lubricant requiring a watt or two or maybe a fraction of a watt more mechanical energy to overcome thickening thereof in a motor whose windings ahave conductivity increased sufficiently to let in 10's of watts?

You need to let something in to your brain. Like rational thought.

On Mon, 5 Jun 2006 05:43:45 +0000 (UTC), don@manx.misty.com (Don Klipstein) Gave us:

In article , Roy L. Fuchs wrote: On Sun, 04 Jun 2006 18:35:53 -0400, Jerry Avins Gave us:
Roy L. Fuchs wrote:
...
A ball bearing is hardened steel, and it will NOT shrink significantly in this scenario... at all.
...
Hardening doesn't reduce steel's coefficient of thermal expansion.
There are reasons that steel is used in the making of a ball bearing, dumbass. Low thermal expansion rates is only one reason.
What does your argument have to do with the hardening point tyhat you were supposedly responding to?

What makes you think that I have any faith in his claim at all? He did not show any numbers from the CRC or any other source.
As far as I am concerned, until he does, a hardened bearing will shrink less than a regular machined steel ball would.

On Mon, 5 Jun 2006 05:51:01 +0000 (UTC), don@manx.misty.com (Don Klipstein) Gave us:

Either find another point to argue on or support contentions that you are the "dungmanure" complained about in the past.

You're a goddamned retard. You were then, and you still are now, so shut the fuck up, jackass.

On Sun, 04 Jun 2006 22:09:14 -0800, floyd@apaflo.com (Floyd L. Davidson) Gave us:

no one that you know wrote: Trus me when it's minus forty it takes more than a few seconds to cook a starter.........but thank you for your concern
Wanna bet?

I cannot believe the lack of real world physics knowledge some of these folks exhibit.
Hell, half of this stuff is part of the basic set of trainings given to auto mechanics, much less engineers.
How many decades have we known that a seized starter causes catastrophic failure of the motor unless the power is removed from it?
How many decades have we known that a dead short across an automotive battery is a *VERY* bad thing to do?
It is a shame that these guys do not know the extent of your experience with lead acid batteries. Much less cold weather car starting. :-]
I happen to know that you have more than a decade worth. :-]
I won't speculate on how many decades...

Roy L. Fuchs wrote:

It is a shame that these guys do not know the extent of your experience with lead acid batteries. Much less cold weather car starting. :-]
I happen to know that you have more than a decade worth. :-]
I won't speculate on how many decades...

4
-- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com

repatch wrote:

... consider that by doing this the pair of pliers weld themselves onto the connections, a car battery pumping hundreds if not thousands of amps through a pair of pliers uncontrolled would cause me to run.

As the battery temp rose 7 F? :-)
Nick

Roy L. Fuchs wrote:

Are you so stupid that you are unfamiliar with multi-graded oils? Well known established fact that cold weather starts require more starter energy.

You are changing the subject.
Nick

Roy L. Fuchs wrote:

Dead shorting a -40 battery or even a zero F battery is NOT going to "warm it" enough to make a subsequent short pass more current.

But it will still explode from its internal energy, right? :-)
Nick

On 5 Jun 2006 04:58:17 -0400, nicksanspam@ece.villanova.edu Gave us:

repatch wrote:
... consider that by doing this the pair of pliers weld themselves onto the connections, a car battery pumping hundreds if not thousands of amps through a pair of pliers uncontrolled would cause me to run.
As the battery temp rose 7 F? :-)

Which is NOT enough to make ANY difference in the CCA capacity of the battery.
It is also a bogus claim. An IR camera pointed at such a battery would see no change in a five second dead short pliers application at any point other than the pliers themselves.
A ten second dead short.. not much more, if any.
After that, we are talking about depleting the battery beyond any gains offered by warming the damned thing.
Again... D'oh!

nicksanspam@ece.villanova.edu wrote:

Roy L. Fuchs wrote:
Dead shorting a -40 battery or even a zero F battery is NOT going to "warm it" enough to make a subsequent short pass more current.
But it will still explode from its internal energy, right? :-)

No it will not. Stop making up straw men to beat up on.
There *will* be sparks. There *will* be excessive heat from the current through the tool used to short the battery.
Either of those can cause hydrogen gas to explode. Either can also cause gasoline, oil, or other flamable material in the engine compartment to catch fire.
These are not common experiences, but they *do* happen and can be extremely harmful to individuals close by.
-- Floyd L. Davidson <http://www.apaflo.com/floyd_davidson> Ukpeagvik (Barrow, Alaska) floyd@apaflo.com