Author Topic: What did I do to this battery? (Read 5106 times)

asheets · « **on:** May 10, 2006, 09:01:05 PM »

I've been putting together a solar system recently. To save money, I've been using old car batteries out of my dad's junk pile.

Anyhow, one of the batteries I pulled out was bone dry. Having reviewed the threads, the 1st thing I did was fill the cells to the proper level with distilled water. A quick check with the voltmeter yielded a reading of around 3 volts.

I tried hooking it up to my Black and Decker 1A/2A smart charger (piece of crap that it is). It wouldn't turn on at all.

So, I tried using a version of this -- http://www.otherpower.com/images/scimages/556/watgas1.gif . After running for an hour, I managed to bring the voltage up to around 10 volts. So I hooked up the Black and Decker again -- it turns on, but cycles between green (charged) and yellow (charging) every 5 seconds. At least the red light (shorted) isn't lighting up. (I really wish I could find an old-fashioned transformered trickle charger like my dad used to have -- no "smart" technology or anything that gets things confused).

So I go back to the watgas1.gif circuit for another hour. It measures 10.8V. Same thing with the Black and Decker again. I leave the voltmeter hooked up to the batter for a couple of days, and the voltage goes down to 10V.

I hit the thing with the watgas1.gif circuit one more time, for 2 hours. At the end, the voltage check reads 9V.

So, what do you think? Did I ruin the battery (no loss if I did), or is there something else I should try? I haven't been to the parts store to get a hydrometer, so I have no idea what the SG is in the cells yet.

I'm about ready to remove the capacitor from the circuit and replace it with a 100W lightbulb, just to see what happens...

Slingshot · « **Reply #1 on:** May 10, 2006, 03:53:42 PM »

If it was "bone dry", you need to add battery acid, not distilled water. I'm surprised you managed to get any charging current into it. Possibly it was not completely dry, but nearly so.

asheets · « **Reply #2 on:** May 10, 2006, 04:36:16 PM »

It was a used battery, not a new one, so I don't think acid would have been a good choice. As near as I can tell, it had been sitting outside for several years., but it had been in somebody's car at some point.

Ungrounded Lightning Rod · « **Reply #3 on:** May 10, 2006, 05:11:36 PM »

It was probably put out to pasture somewhat less than fully charged. (If it had been fully charged you'd get essentially no acid into the water. If fully discharged it would have almost enough sulphate in the plates to bring the acid content up to the correct level - but it would probably be sulphated into oblivion.)

You should run a desulphater on it to get it as charged as it will go - then dump the electrolyte and replace with with a water/sulphuric acid solution at the correct pH for a charged battery.

asheets · « **Reply #4 on:** May 10, 2006, 05:39:11 PM »

OK, so just to be clear about this, as this doesn't quite jive with some of the other posts I've read...

A discharged battery should NEVER have new electrolyte put into it, because there is "acid" in the plates already?
A charged battery can have new electrolyte put in as long as it is guessed that the battery has the maximum charge it can (so there is no "acid" in the plates)?

So, back to the original scenario... my voltage went down after my last charge attempt. Is all the acid I can expect back in the fluid now, so I can dump the 'lyte and replace it?

Dang, I wish I had money for new batts...

BT Humble · « **Reply #5 on:** May 10, 2006, 07:55:29 PM »

(I really wish I could find an old-fashioned transformered trickle charger like my dad used to have -- no "smart" technology or anything that gets things confused).

They're pretty easy to construct. You should be able to make a 12V/4A one using new parts for under $20.

BTH

asheets · « **Reply #6 on:** May 10, 2006, 09:03:37 PM »

I've thought about it, but I doubt anything I could put together would match the robustness of my dad's old unit. I used to hook up a battery-powered air compressor to the thing and pumped up thousands of bike tires doing it (I was a dumb kid). Make oxy-hydro with it? Not a problem. Launch model rockets? Sure! Set fire to steel wool? It could do that too. Leave it hooked up while starting my 1st car on a cold day? It didn't even blink. That old thing was designed to be abused by people like me.

If I did the same things with a modern charger, the charger wouldn't last a day. If I built one and did that, maybe it would last a week.

asheets · « **Reply #7 on:** May 10, 2006, 09:09:32 PM »

OK, here's where I am now. When I got home today, I bypassed the capacitor in the watgas circuit and ran it straight for about 5 minutes. The plates buzzed and crackled for about 30 seconds, then stopped, and the 'lyte started bubbling lightly. The surface of the 'lyte had a brown scum on it, which I suctioned out.

After that, I checked the voltage -- it now read 11.3V . Didn't have time to test it with the B&D or the restored watgas circuitI'll check it again in the morning. I still have to get a hydrometer too.

Ungrounded Lightning Rod · « **Reply #8 on:** May 11, 2006, 01:07:41 AM »

sounds like you just blew the sulfation off the surface.

Ungrounded Lightning Rod · « **Reply #9 on:** May 11, 2006, 01:11:13 AM »

Is that measured with the charger connected? Or disconnected?

If measured while charging, a voltage drop indicates that you're breaking through or dissipating the sulfation on the surface of the plates, which is a pretty good insulator and causes a resistive voltage drop that ADDS to the battery potential during charging to produce the voltage you measure.

If measured after turning off the charging you need to be consistent about dissipating the "surface charge" before measuring, or your measurements won't be comparable.

dinges · « **Reply #10 on:** May 11, 2006, 02:26:40 AM »

Fully agreed here!

I hate smart chargers. The kind that won't let you charge if they think that there's no (or the wrong) battery connected. So that, if your battery voltage dropped to 6V, they won't charge because they expect a 12V battery to be connected.

Let the charger do the charging. I'll do the thinking, thank you.

Peter.

Foolproof isn't.

commanda · « **Reply #11 on:** May 11, 2006, 03:03:06 AM »

I have long held to the belief, that if you make something idiot-proof, then only an idiot will use it.

Amanda

BT Humble · « **Reply #12 on:** May 11, 2006, 03:30:58 AM »

I have long held to the belief, that if you make something idiot-proof, then only an idiot will use it.

I heard this one being related to software engineering, but it'd probably apply to any kind:

"Software engineering is an ongoing battle between software engineers, trying to make idiot-proof software, and the universe, which is trying to make better idiots. So far the universe is winning."

BTH

pepa · « **Reply #13 on:** May 11, 2006, 06:44:08 AM »

hi alan, my third and last smart charger died and i will not buy another one. i have a old 14v cordless drill that the battery died on and another battery would cost more than the drill, so i made a set of jumpers to run it off the charger, and use it as a spare shop drill. this same set of jumpers and charger will also charge 12v batteries or run my 19v cordless tools while their batteries are charging in their regular chargers, if i need them. makes a nice little cheap battery charger. pepa

Norm · « **Reply #14 on:** May 11, 2006, 08:03:57 AM »

For about $10.99 plus tax you can get a spot

light 12volt rechargable battery and trickle

charger included...the longer I look the cheaper

they get ....

( :>) Norm.

Norm · « **Reply #15 on:** May 11, 2006, 08:24:04 AM »

Once you get the hang of bringing dead batteries

back to life you may discover that junk dealers

have deep-cycle batteries that they are willing

to part with for a buck or two more than they'd

get for junk win win for both parties...after

awhile they may even set the more promising

candidates aside for you ...been there ...done that!

as have others..

After awhile you get the

feeling you're ripping them off...LOL !

( :>) Norm.

asheets · « **Reply #16 on:** May 11, 2006, 08:27:35 AM »

This is measured with the charger disconnected and about after a minute. I will keep this in mind, though, for consistancy.

asheets · « **Reply #17 on:** May 11, 2006, 08:31:36 AM »

SOunds like it. I ran it for an hour on the watgas circuit, then checked again. 11.9V. I hooked up the B&D "smart" charger, set it to 1A, and it is cycling between "yellow" and "green" about every 5 minutes (before, it was cycling every 5 seconds). The B&D still won't work at 2A, though.

Anybody think there'd be any harm to "buzzing" the thing one more time?

asheets · « **Reply #18 on:** May 11, 2006, 08:37:41 AM »

from despair.com...

"In the battle between you and the world, bet on the world."

Ungrounded Lightning Rod · « **Reply #19 on:** May 11, 2006, 01:01:37 PM »

It's a good idea to discharge it for a few minutes before measuring, to remove the "surface charge" and get down to the basic charge of the plates. If you just measure the voltage a minute or two after the charge you'll see surface charge and get readings that are also confused by cell-to-cell leakage variations as well, which will pull off some of it and rapidly drop the voltage on any leaky cells. So you'll be measuring a mix of things, with minor matters making large differences in your readings.

I don't recall the recommended time and discharge rate (as a percentage of capaicty rating) but there are plenty of battery sites out there with suggested values.

hvirtane · « **Reply #20 on:** May 11, 2006, 01:33:55 PM »

Why not trying with the 'watgas' circuit

some hours? I think that without the capacitor

it might break the whole battery...

- Hannu

asheets · « **Reply #21 on:** May 11, 2006, 01:36:11 PM »

I haven't wanted to leave the battery unwatched - -and so far the longest stretch I've been able to watch the thing is 2 hours. Maybe this weekend I'll leave the thing hooked up.

elvin1949 · « **Reply #22 on:** May 12, 2006, 06:56:35 AM »

HAHAHAHA

How true.

later

elvin

hobot · « **Reply #23 on:** May 12, 2006, 09:01:18 PM »

Sediment can collect at bottom of plates to short out.

Sometimes must phsyically invert and shake this out, a few goes,

then refill and charge. Acid part does not evapoarte away with

the water just gets more concentrated till sulfur salts that reconvert

to 'lyte as charged back up.

Migtht monitor the specific gravity also.

hobot

BT Humble · « **Reply #24 on:** May 12, 2006, 09:22:17 PM »

I've thought about it, but I doubt anything I could put together would match the robustness of my dad's old unit. I used to hook up a battery-powered air compressor to the thing and pumped up thousands of bike tires doing it (I was a dumb kid).

Nah mate, you were a LAZY kid! ;-)

BTH

(Not that there's anything wrong with that!)

asheets · « **Reply #25 on:** May 30, 2006, 11:36:38 AM »

I just wanted to give everybody who was interested an update on this.

I got the thing charged and holding to just shy of 13 volts, and could start a car with it. However, two of the cells would not hold a charge. Further runs of the desulphator would trip the circuit breaker.

Looking at the 'lyte in those two cells, after charging it would be frothy and brown. Considering where the battery sat for who-knows-how-many years, I figured that the 'lyte was full of dirt or other contaminates.

I was correct. In 4 of the cells the 'lyte was clear to purple-clear. In the other two the 'lyte was brown. While the 'lyte was out, I took the opportunity to wrinse the insides of the cells with pleny of distilled water -- and got lots of "gunk" out of all 6 cells.

So, two new questions:

How does one go about filtering used 'lyte?
Or, since I charged the battery to rated voltage before dumping the 'lyte (so that the lead plates are as acid free as possible), should I just put in a fresh batch of 'lyte?

BTW, I've heard and read that one should never put fresh 'lyte in a discharged battery. What is the exact problem if you do that, though?

News:

Author Topic: What did I do to this battery? (Read 5106 times)