Cooked battery?

[craig110]

Oh nuts.  I opened the battery compartment to do a long-overdue PM on my Trojan T-105s and found that one battery has a terminal that is melted like this:

(Ignore the fluid.  I took the picture after topping off its cells with distilled water.)

I disconnected the battery bank for the PM, of course, and have not reconnected it back yet.  I presume that this is now an unsafe battery to use?  (Probable understatement.)  What likely happened?  This particular battery is the first one on the "positive" side of the chain of 8 T-105s in serial if that gives a clue to what happened.

[rossw]

Without a closer inspection, my GUESS would be that the grub screw that clamps your cable to the terminal was never sufficiently tight, or you've had the cable oxidise, or it's "worked loose" as terminals sometimes do.

This results in a small amount of resistance, which causes heat, which makes the process happen more, and more quickly. Notice the melted insulation on the cable, and the discolouration of the metal clamp.

Heat will conduct down and through the metal of the terminal, and the battery post itself.

The battery case plastic isn't designed for high temperatures, and over time I suspect the heat from the failed connection (and probably subsequently where the lug connects to the terminal) have all taken their toll.

I could be wrong, but thats my first thoughts from what I can see.

[halfcrazy]

I have to agree it looks like a failure of the set screw conection causing it to heat. but i would say battery is probably useless now?

[wpowokal]

I concure with over heating from loose terminal but if the positive terminal is still sound then it's most probally usable.

What looks like a small hole in the top of the case can be plugged. It might pay to look inside (safety glasses)  in case some molten terminal has gone through to the plates.

allan down under

[richhagen]

I have had occasion to cook a battery terminal or two.  If you have a bad connection, that has a fraction of an ohm of resistance, and run a few hundred amps through it, you can easily melt a terminal off.  If the battery is newer, and otherwise tests out OK, you can probably repair the terminal.  Having an electric car, I have had to improvise to get around this problem and salvage an otherwise good battery in the past.  

I have repaired a couple of terminals by making a mold out of wood and lining it with dry plaster powder to protect the plastic, scoring the remaining lead surface (so that the new lead will bond with it) and casting new hot lead on around a new bolt and over and around the remnants of the old terminal to make a new terminal.  They are not usually as pretty as the original, and I'm always a little leary of the repaired terminals I have made at high amps, but they do work.  Looking at your picture, it looks like the case might have a hole in it, which you would want to patch first.  

It is a good idea to periodically check all of your terminal connections to ensure that they are tight, as from my experience with the electric car, a loosened terminal combined with a high amp draw is the usual cause.  Rich

[rossw]

As with so many things, "20/20 hindsight".

I try to "eyeball" stuff often. At least weekly, usually daily (unless I'm out of town). This doesn't mean a full maintenance - it just means being "aware".

Anything smell odd? CHECK IT!

Anything look unusual? CHECK IT!

Voltages seem unusually low or high? CHECK WHY!

I also periodically (at least weekly) just quickly go past the battery bank checking the temperature of each cell. Only takes a second or less per cell (I usually do two at a time). Then run back along the bank checking the temperatures of the interconencts themselves.

My trojans are all edge-on-edge, so I check the case temperatures, and also give each one a gentle "thump" with  the end of my fist. I once found a cell going bad because it was consistently gassing much more than any of the others by this technique - give each cell a light thump and sometimes they gurgle as settled gas is knocked loose.

This goes for just about anything around the place. Motorcars, generators, turbines, pumps. Just "be aware". When things change, investigate WHY something is different. If the water level in the dam or your tank suddenly changes, check WHY. If your hot water is suddenly hotter (or colder) than usual, CHECK WHY. If your icecream is soft, or your milk goes sour after only 3 days - CHECK WHY!

I know another thread goes on about the danger of having your batteries inside and how they need to be locked way in a bombproof shelter at the far end of the garden, but honestly - how often do you check them? "Out of sight, out of mind" is not just a saying - its a reality.

YMMV, just my opinion, etc.

[willib]

hi richhagen, you have an electric car?

do tell

i thought that jerry was the only one here with an electric car/truck..

my apologies to craig110 for taking his post on a diversion.. but i'm sure he wont mind ?

is it all electric? a hybrid? inquiring minds wish to know..

[RogerAS]

rossw,

You wrote:

"I know another thread goes on about the danger of having your batteries inside and how they need to be locked way in a bombproof shelter at the far end of the garden, but honestly - how often do you check them? "Out of sight, out of mind" is not just a saying - its a reality."

I take exception to your remarks about the battery box thing.

I would think the picture presented in this thread is a prime example of WHY those batteries needs to be away from ones house.

You're entitled to an opinion even if it's wrong. Guess what? You're wrong to take such a stance about safety, and that IS NOT opinion but the law here in the USA.

Just because batteries are in an enclosure away from the house is no excuse to ignore them. I never made such a statement. I never even implied such a thing. If I'm wrong show me how. Until then I suggest you show a little more respect for those trying to look out for those that are simply ignorant, outright fools and or complete idiots. Place yourself among this group as you see fit.

IF you feel so strongly why not comment in that thread and not sneak around doing so here? Especially considering what the OP found with his battery??

OR, go ahead and ignore safety rules and burn your house and family into crisps. I don't really give a rats behind what you do, but I do care that you dismiss sound advice, and the law, because you feel like being a smart XXs.

That's my take on your opinion, and your method of presenting same.

Good day sir.

[rossw]

ROFL. You yanks just "don't get our aussie sense of humour", do you!

Mate, you can take exception all you like, if I meant to rag on you, you'd be in no doubt that was my intention. The "over-exaggeration" is a common aussie trait, not to be confused with taking the piss, mate.

[halfcrazy]

I still have yet to find where the nec says they cant be in the house? i still stand by that in the real cold climates like ours a good rugged SAFE battery box is the way to go. I mean i hear people saying put them in the attached garage what the Heck is that is the house still not going to burn down? as a licensed electrician and General contractor i can speak with some experience that the 1 hour fire rating that is supposed to be between garage ad home usually isnt.

Again give me some nec articles stating they arent allowed in the house i just cant find it i read the supplement someone here had also still couldnt find it. i agree they shouldnt be beside the bed or what not and if you have a semi heated outbuilding that would be great but if you dont??? If the box is built right it will contain any catastrophic failure long enought o get out.

i would venture a very wild guess that propane leaks in homes cause more catastrophic losses then do baterys

[RogerAS]

Halfcrazy,

I previously posted a link to the PDF I have placed within my files.

Here it is again.

http://www.otherpower.com/images/scimages/93/NECV1_6.pdf

There are such things as heating mats, and other warming systems, for batteries. Cold climate battery use is no excuse for compromised safety.

The entire point is why take the risk of burning the house down at all? Sure those residing there MIGHT get out in time, but there's also a chance they MIGHT NOT.

Propane appliances are certified by underwriters labratories. To assert that batteries and propane use are comparable dangers is a straw man arguement. Does a sane person place the propane tank inside the house? EVER? The number of battery installations compared to gas installations is an absurd ratio, and no such cetification process exists for battery placement except for the NEC code.

If a house burns because of a battery failure do you think the insurance will cover it? Even if a local inspector does sign off I doubt they (insurance co.) would pay if the fire marshall rules that batteries were the cause.

The inspector MIGHT lose his job. Big deal!

Do YOU want to be held responsible if a family loses their homes, and worse yet a life, because your installation was not up to the NEC? One might lose his freedom as well as that contractors liscense. Can you say "negligent homicide"? Can you say "civil suit"? Lawyers and district attorneys drool at such prospects.

The entire issue is why do it at all when it is far easier to put the freakin' batteries outside and sleep well at night?

I really do not understand the objections.

----------------------------------------

Rossw,

I must have read your comment incorrectly and I am sorry if that was the case. I personally find very little humor in burning houses and the families that reside therein. Indeed you boys downunder must have a unique sense of what's funny. The genocide in Darfur must be a real blast for you guys.

[halfcrazy]

i have read that pdf still cant finda code article that says its illegal to do? my latest code class the instructor couldnt either and multiple installers i talked with say the same? if i could see a article in the nec specifically prohibiting it period i would change my ways but i just cant find it

[rossw]

shakes head

Humour. You should try some, sometime.

I'm NOT saying I find houses burning down funny.

NOR that people being killed is hilarious.

Experienced my fair share of both, thankyou very much. Check out the fires in Melbourne, Australia circa 1982. I was there in the thick of it the night Emerald was burned to the ground, and was very close to being one of the statistics myself.

The "aussie humour" was more in the over-exaggerated reference that you seemed to find so personally offensive, and no amount of my explanation of how us "down-under" people think, talk, act and have fun is going to help to appreciate it.

"I can explain it to you, but I can't understand it for you"

[snowcrow]

I have read that pdf also, and find this,

This "suggested practices" manual examines the requirements of the 2005 National Electrical Code (NEC) as they apply to photovoltaic (PV) power systems. The design requirements for the balance-of-systems components in a PV system are addressed, including conductor selection and sizing, overcurrent protection device rating and location, and disconnect rating and location. PV array, battery, charge controller, and inverter sizing and selection are not covered, as these items are the responsibility of the system designer, and they in turn determine the items in this manual. Stand-alone, hybrid, and utility-interactive PV systems are all covered. References are made to applicable sections of the NEC.

National Electrical Code and NEC are registered trademarks of the National Fire Protection Association, Inc., Quincy, Massachusetts 02269

The second and third word, "suggested practices". As long as the Electrician signs off on the installation, you're golden!!!

A couple of facts:

Fact 1: A fully charged Lead-Acid battery will freeze at -70 to -75F!!

Fact 2: For every 10F below 40F, you lost 10% of your charge capacity!!

Fact 3: It can reach -40F during the day where I live!!!

Its just not feasible to put the batteries outside.

Blessings, Snow Crow

[halfcrazy]

thats exactly my take on it to

[TomW]

Guys;

I have to agree here it is not remotely sane to put them in an unheated space part of the year. We see double digit sub zero [F] temperatures for weeks on end occasionally and then there are those snow drifts that will block easy access to keep an eye on them.

Like many things, if you don't have the sense to pour urine out of a boot you should hire it done. If, however, you have fair common sense and you take reasonable precautions there is really not as much danger as it appears on first glance.

I think it is very important to understand the dangers of batteries because they do exist. Properly vented on a non combustible floor in a sealed box that requires removing locks, screws or some other deliberate process to gain access and away from ignition sources should be safe enough for most adult situations. With kids you need more security for curious fingers.

On another note, I did not see any reference to lead me to believe the "never inside an occupied structure" bit.

I won't even mention sealed and gel types that probably can be used in any location.

Do not get me wrong, stupid, lazy or mentally challenged folks should hire it done by a pro but sensible folks with knowledge of the dangers can probably install a perfectly safe flooded lead acid battery bank in a garage or corner of the basement with proper precautions. Getting the advice of a pro would be wise, also.

Not trying to downplay the validity of safety concerns just offering an opinion of a guy who uses a bank every day in the corner of his office with no concerns about the safety of it.

I do feel it is good to have these debates so folks can get various opinions. Lots of this stuff is so new or uncommon that there are not a lot of folks who really have deep knowledge of all aspects of what we do.

Cheers.

TomW

[halfcrazy]

I much agree o the debates as it really helps people be aware of the simple safety steps. there is no place in the nec i can find that says they cant be in the house and it is no different then the mains power coming in that is unfused and very dangerous we simply house it in a safe box. as a licensed electrician and a fairly seasoned installer i will continue on down the road i am on as it just makes no sense at all to keep them outside in our cold temps. But agree keep them in a strong, SAFE,VENTED PROPERLY and LOCKED battery box and they will be fine and they will be fine and wrost case the box should contain a exploding battery. witch by the way most batterys i have ever headr or seen blow up just do that there is no fire just a battery in peices so contain that and you will be fine

[craig110]

Update on the battery: I looked down inside the hole, and it appeared that some of the terminal lug had melted and dripped into the hole.  Instead of risking messing with it, I just replaced the battery today and tightened every lug bolt and grub screw throughout the bank.  Thanks for the help, everyone!  I will definitely keep an eye on this from here on.

By the way, on the "does the NEC allow indoor battery banks" issue: When my setup was inspected, the local inspector brought an ex-state inspector along since he had experience with solar setup inspections and now installs them.  Lead-acid battery banks inside are not against the NEC.  The only comment he had was a suggestion (that he emphasized was only that as that code did not even mandate this) to enclose the batteries and vent the enclosure up and out of the garage so that any generated hydrogen will vent outside.

[halfcrazy]

actually craig the nec does require proper ventilation and also aurding of live parts against unquailifed personel so if the room they are in is vented and locked you are good to go glad to here you found another battery keep an eye on those lugs and hapy charging

[Ungrounded Lightning Rod]

Fact 4:  Batteries produce heat when charging AND when discharging.

Fact 5:  A well insulated battery container requires only a small amount of heat to keep it toasty.

I'd go ahead and put my batteries in an insulated outdoor enclosure in an area where winter night temperatures drop to double-digit-negatives on a regular basis.  But I'd try to arrange my vents so the wind wouldn't encourage the air circulation and that only enough was allowed (at least in winter) to safely vent hydrogen.

And I'd put in a couple of 100W resistors (2.4 ohm for 12v, 9.6 for 24, ...) under the battery racks, controlled by thermostats (set around 40 - 45 F), to provide redundant 60 W heat sources for the shed - mainly to keep the replacement water jug from freezing if the genny happened to match the load for a couple hours straight on a really cold night.  (And I might record whether they ever turn on, just for the heck of it.)

Can't talk from experience.  Only from lore.  But that's really how I plan to do it at my mile-high Nevada place.  (Maybe not as cold as a mile-high Alaska place.  But winter nights in the high desert are not for the unsheltered.)

But: an thee harm none, do what thou wilt.  It's not just a good idea, it's the law.  B-)

[richhagen]

I have a 1981 Commutavan that is all electric.  A couple of hundred of them were made for the post office as an experiment.  It has a 72V motor and a motor just shy of 72V.  It has a 300 amp meter that is easily pegged when one stomps on the accelerator - hence the melted battery posts.  It has a top speed of about 45 mph, 50 if it's flat or the wind is favorable.  The range was supposed to be 70 miles originally, however I have only seen about half of that with the golf cart batteries I put in it.  It accelerates slowly, and garners quite a bit of attention as you drive it.  It is licensed and insured, but I don't drive it much.  Rich

This is a picture of it from when I picked it up.  It is right hand drive.

I also have a hybrid Ford Escape which I got last October that I use for most of my driving now.

Ford Esape Hybrid on 11 April 2007, not a good picture but the only one I found of my car on the computer.

[willib]

Thanks Rich , pretty cool stuff :-)