Author Topic: battery boiling (Read 7316 times)

Birdmmjb · « **on:** July 29, 2007, 10:28:24 PM »

I have been given 4 T-105 batterys and have been slowly bring 2 of them up to charge with an 80 watt panel.

Today when I walked by the bank I heard the batterys boiling. The charge meter showed that the bank was at 14 vdc while being charged by the panel.

Is this normal to hear them boiling or is there a problem? these are free and I dont know anything other than they are taking a charge as the resting volts have been climbing each night.

I disconected the bank until I could find out from all of you if this is allright or not. The current resting voltage is 12.3 vdc.

Thanks in advance

Jan

DanB · « **Reply #1 on:** July 29, 2007, 05:57:55 PM »

Odds are they're shot. Sometimes though a good battery can sit around dead for a while and it gets sulfated and boils at pretty low voltage. If you keep charge on it for a long time (and you might need more than just an 80 amp panel) the voltage at which it 'boils' may rise and the battery might come back to life. 12.3 volts is below full charge - it would be interesting for you to put a good load on them and see how much capacity they have.

two signs of a 'dead' battery (if I see these I don't even bother)...

if the sides are bulged out and hard (you cant push in on them because the plate have expanded. Lots of batteries have sides bulged out but you can usually push them in by hand.
if the positive terminal has 'raised' (the top of the battery is no longer flat near the positive terminal, it actually sits up a bit higher than the negative one. Sometimes you'll even see stress marks or cracks in the plastic around the pos. terminal.

Birdmmjb · « **Reply #2 on:** July 29, 2007, 06:10:57 PM »

Thanks Danb, the batteris were dead dead dead when I got them. I got them to a whopping 10.6 volts the first day of charging and have been getting a higher and higher resting charge each night I've had them on the panel about two weeks and was thrilled to see charging volts at 14vdc at last.

Is it safe to keep charging these I would hate to blow them up and make a mess?

There are 2 more that I have been given but have not tried to charge them yet. I have checked and they do have some distortion on the cases but I can press it in to some degree.

Just for grins I ran my 5watt dc lamp on this bank the other night in over an hour the voltage did not drop we started at 12.2 and remained there till I shut off the light and went to sleep.

I know that was not much of a load but I dont have anything that draws much yet just the light and one of the treadmill motor fans that built after seeing one on this site.

I think I will turn both on and get a better idea tonight what it will do even at this low a charge.

Jan

Flux · « **Reply #3 on:** July 30, 2007, 02:18:56 AM »

I agree with Dan, and you have confirmed that they are scrap.

If you get enough capacity out of them to do what you need then keep using them. Let them boil at 14v, they may get better, just add water when needed and make sure nothing ignites the gas. ( keep terminals tight and keep all source of ignition away).

They may be incapable of high current discharge but you don't seem to want that so it should be fine.

If you want to spend money and effort you could try EDTA, it may help but don't expect much. You can try desulphators but again I have never seen one do any good.

They may improve with use but will never regain anything like their capacity.

As I said, if you can live with their limitations that's fine, if you really want batteries that work, ditch them and save a lot of wasted effort.

They will probably die from shorted plates caused by moss growth through the separators but until then you may get a few years of limited performance.

Flux

whatsnext · « **Reply #4 on:** July 30, 2007, 07:15:12 AM »

I've had better luck with EDTA than Flux apparently so I would try that. Your cells don't appear to be shorted and they are storing some energy so add some EDTA and keep them topped up. Then, hope for the best.

Birdmmjb · « **Reply #5 on:** July 30, 2007, 08:02:31 AM »

thanks for your insight on these batteries.

For now I will keep using these as I dont have the funds to buy new. I will start a fund for new now rather than more solar panels as I know that more solar with out good storage is a waste.

I ran the batteries for 2 hours last night starting volts 12.3 it droped to 12.2 after 2 hours and back to 12.3 when disconnected. I heard them girgle and disconected them for safty right now they are in the house as I wanted to keep a close eye on them. they will now go to outside storage as I dont trust them and dont want them to blow up in the inside storage room.

Thank you I really need this group as my field of study is medical technology and am quite clueless unless I have read it here.

Jan

SteveCH · « **Reply #6 on:** July 30, 2007, 09:35:41 AM »

Boiling is usually only acceptable during intentional overcharging. It is normal in my C&D forklift batteries to get some "simmering" when near full charge [in my case, I use 14.2 v. but makes of batteries are different here]. How do you control overcharging? If it's with a charge controller, set the upper voltage limit to the point before the actual "boiling" begins. This may take a bit of trial and error and a little time. Boiling will use up lots more water, so keep an eye on the levels until you get it solved.

By the way, I've had a couple episodes where I had problems with boiling and as far as I can tell, the temporary situation did not damage my batteries. Or, if it did, I haven't been able to tell the difference. My batteries are about 14 yr. old now, still going ok though not quite as ok as when new.

I purchased on of the "desulfaters" and did so at a time when I was having some problems keeping the batteries up to charge. Same time, I added a couple more pv panels. I didn't have time, I felt, to wait out the desulfating process [assuming it really did anything] before adding the extra charging capacity. So, I cannot attest to the benefit, if any, of the desulfator. Maybe someone else here can...if so, they run maybe $40. I'd keep using those batteries as long as you get the job done. There is really no benefit to buying new or newer ones if you can keep those going a while longer and if they are safe enough.

solarengineer · « **Reply #7 on:** July 30, 2007, 02:52:30 PM »

Whatsnext, just a quick question on edta... how are you using it? I dissolved 2tablespoons in 200ml of distilled mixed good and added that amount to each of my 2V cells and I found now that the voltage wont rise above 14v, capacity is still on the low side and when i use a hydrometer on the electrolyte it shows worse than before adding the edta..

Thanks

jamie

Ungrounded Lightning Rod · « **Reply #8 on:** July 30, 2007, 08:53:26 PM »

EDTA works by dissolving the lead sulphate from the plates and removing it from the reaction. This removes material that might be blocking the plates' pores and/or producing an insulating coat interfering with charging. But it also removes material that is just the plate in discharged condition.

I'd keep watering and charging the batteries until I'm no longer seeing an improvement, THEN add EDTA. That way I'd have put as much lead sulphate back to work as possible before "firing the rest of the bums".

Note that the growth of large lead sulphate crystals may have damaged the internal structure of the plates. In that case the batteries are probably toast in short order due to the imminent disintegration of the plates - and the EDTA might trigger that final demise by dissolving some of those crystals.

(Or at least that's the impression I get from reading about this stuff.)

Birdmmjb · « **Reply #9 on:** July 31, 2007, 06:29:41 AM »

I have a 7 amp charge controler it is preset to 14.5 shut off. There is no way to change the setting.

This system was started to be a back up to run the fan for my buck stove in the event of a power falilure.

Several years ago we were without power for 10 days due to an ice storm. We had a fire in the buck but with out the fan it did little good.

We have sence moved and now have gas so the system has changed to provide light and air movement during the summer and light and ?? during the winter.

Being me I had to give my back up a steady job as I could not see waisting the excess power once the battery was charged.

I have added the batteries in question and a wind mill to the mix but lost the blades several weeks back and dont have it or its dump load working right now.

I have cut and cut at the power bill but see that we will never be off grid. (my dh cant stay in the house without every light in the house on. I've even come in from from work at night and found all the lights on and him asleep. He tells me a dark house depresses hem. The electric bill depresses me.)

Oh well I'll cut where I can and keep running behind him turning off lights

Jan

DamonHD · « **Reply #10 on:** July 31, 2007, 09:11:47 AM »

Make sure all those lights are CFLs at least!

Rgds

Damon

Birdmmjb · « **Reply #11 on:** July 31, 2007, 05:17:55 PM »

Well the jury is in and the 2 batteries are tost.

I picked one of them up to move it today and a large amount of acid leaked from the seam arround the top of the battery.

I cant think what would have cased this as they did not leak when I got them.

The other 2 seem to be allright I'm going to hook them up tonight if I have time. this time it will be in the outside stroage as this has been a lesson.

I may not be able to keep as close an eye on them out there but they can blow up out there with out damaging anything I care about.

Jan

Capt Slog · « **Reply #12 on:** August 03, 2007, 12:39:17 PM »

It's also worth having a sniff around the battery for hydrogen sulphide, this is usually produced when the battery is under a heavy load and is indicative of a dead cell. When this gas is produced the cell is acting as an eletroysis cell under the current of the rest of the circuit. (I've no doubt I will get corrected on this, but that is how I understand it as a chemist).

Please beware of hydrogen sulphide, it is DEADLY. It also has the unfortunate property that when it goes into lethal concentrations in air, it no longer smells, and you can think (for a short while) that it has gone away.

Written sitting in an internet cafe in Crete on my hols.

TomW · « **Reply #13 on:** August 03, 2007, 01:35:41 PM »

Capt;

Please beware of hydrogen sulphide, it is DEADLY.

I am curious what it smells like or how to recognize it?

Occasionally upon opening my battery box after they have been charging I get a slight whiff of what smells a bit like chlorine but very faint.

Thanks.

Hope you are enjoying Crete.

Cheers.

TomW

DamonHD · « **Reply #14 on:** August 03, 2007, 02:44:42 PM »

Hydrogen Sulphide (H2S) is the smell of rotten eggs. You can smell it maybe 1 part in 1 million million but it can kill you one part in 1 thousand million IIRC. Nasty stuff.

Rgds

Damon

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