Author Topic: Alum battery conversion.  (Read 16800 times)

Offline DavidA

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Re: Alum battery conversion.
« Reply #25 on: February 28, 2015, 02:45:35 PM »
Here are the results of today's discharge test.  Load was the same 12 Volt 50 Watt lamp as before.

Note.

The battery had been charged for around 24 hours after the last test,  then left standing for 5 days.  The voltage across the battery prior to the test was 10.6.

12:30      7.3 Volt     3.3 Amp

12:45      11.2          4.2

13:02      11.6          4.3

13:16      11.7          4.3

13:30      11.7          4.25

13:45      11.5          4.25

14:00      11.8          4.2

15:00      11.4          4.2

15:20        8.4          3.5

15.30       11.7         4.2

15:45       11.3         4.15

16:00         8.7         4.15

16:30        11.3        4.1

16:45        11.3        4.1

17:00        11.3        4.1

17:15        11.2        4.15

17:30        11.1        4.1

17:45        11.3        4.1

18:00        11.2        4.1

18:15        10.8        4.1

18:30         10.7       4.1



Duration of test 6 hour.

This battery appears to be improving.
Notice how the measured voltage is higher when under load than it is when it was standing with no load connected.
There are a couple of occasions when the voltage drops,  but it recovers .
At the time the test was discontinued it was still providing 4.1 Amp although the voltage was beginning to drop off.

The next test is to use two lamps to double the current.

Dave.

Offline vtsteam

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Re: Alum battery conversion.
« Reply #26 on: February 28, 2015, 03:24:00 PM »
So that's something like 26 amp hours (so far), and 1.9 V per cell (more or less). Which is pretty good for a dead battery!

I don't know how the capacity holds up against a similar size lead acid battery in good condition. I do have some bigger deep cycle marine batteries, about 50% larger that have 100 amp hour capacity. I always assumed a regular car battery was up around 60, but I don't know for sure.

The rise from a lower resting voltage seems typical for these alum batts, and the ability to hold a charge for a longer period without self discharge. Also, somewhat lower cell voltage.
I love it when a Plan B comes together!
Steve
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Offline DavidA

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Re: Alum battery conversion.
« Reply #27 on: February 28, 2015, 03:59:03 PM »
VT,

...I don't know how the capacity holds up against a similar size lead acid battery in good condition...

I was wondering along the same lines.

I have a good battery off one of my cars that I will charge up and run a test (or two)on.

Next step with the alum battery is to investigate the Specific Gravity aspect.  Does it behave the same as when using Sulfuric acid ?.  Much measuring to be done.

But I really do need to automate the measuring process. Taking readings every quarter of an hour is ok if I'm in the shed,  but a bit of a chore if I have to make special trips.

I do have the data gathering and logging equipment,  just need to set it up.

Dave.

Offline awemawson

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Re: Alum battery conversion.
« Reply #28 on: February 28, 2015, 06:30:45 PM »
No problem, get the wife to take the readings when she's between ironing session  :lol:
Andrew Mawson
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Offline DavidA

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Re: Alum battery conversion.
« Reply #29 on: May 20, 2015, 03:54:25 PM »
Just need you guys to humour me for a bit.

During my trawl through the various desulphating offerings I found the following.



Some of you may have seen it.

But regardless,  I would like you to have a quick look at it,  the first minute is enough,  and see if you spot some thing odd.

Dave.

Offline Manxmodder

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Re: Alum battery conversion.
« Reply #30 on: May 20, 2015, 05:13:12 PM »
David, opening that link has just crashed my computer at about the 1 minute mark. I sincerely hope you didn't know that was what would happen......OZ.
Helixes aren't always downward spirals,sometimes they're screwed up

Offline tom osselton

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Re: Alum battery conversion.
« Reply #31 on: May 20, 2015, 06:27:36 PM »
Worked fine for me.

Offline Will_D

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Re: Alum battery conversion.
« Reply #32 on: May 20, 2015, 06:29:23 PM »
No problem for me! At 1 min in couldn't see owt wrong or odd!
Engineer and Chemist to the NHC.ie
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Offline Sea.dog

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Re: Alum battery conversion.
« Reply #33 on: May 20, 2015, 06:31:51 PM »
The only thing obvious to me was that he was talking Ohms when clearly the meter was showing milli-Ohms.

Graham

Offline Manxmodder

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Re: Alum battery conversion.
« Reply #34 on: May 20, 2015, 07:12:52 PM »
Yes,I did notice the Milli ohms reading.
Helixes aren't always downward spirals,sometimes they're screwed up

Offline vtsteam

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Re: Alum battery conversion.
« Reply #35 on: May 20, 2015, 09:46:33 PM »
I watched the whole series of 5 videos. Apparently, I can't stop watching  a bunch of predictable failures unfolding at a snail's pace.   :doh:
I love it when a Plan B comes together!
Steve
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Offline DavidA

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Re: Alum battery conversion.
« Reply #36 on: May 21, 2015, 06:17:19 AM »
Oz,

No,  I didn't find any problem with the link. I have watched it a couple of times without incident.

And congratulations to you others.  It was the way that he kept referring to Ohms when the meter was showing milliOhms that had me puzzled.

Makes you wonder a bit about the rest of the 'advice'.

Thanks for partaking in this little experiment.

Dave.

Offline vtsteam

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Re: Alum battery conversion.
« Reply #37 on: May 21, 2015, 10:16:25 AM »
One other point, among many about this series of videos, is that as he explains it, the Harbor freight meter he is using is measuring internal resistance of the battery in order to calculate "cold cranking amps", rather than putting the battery under starting load and measuring actual cranking amperage.

That may work okay if the electrolyte is standard sulfuric acid, the concentration is correct, the cells are filled, and the terminals have good contact, so the resistance is reasonably accurate.

But as soon as you change the electrolyte, its resistance changes. You have just changed the resistance of the solution, not necessarily "restored" a battery or somehow repaired a bad cell.

And his advice to spoon in wetted epsom salts (he actually spoons in dry salts at one point) with no attempt to measure ( a few cells he arbitrarily adds more to half way through his tests) is kind of like a kid making a mud pie, and pretending to be scientific about it.

Unlike other youtube epsom salt/lead acid battery conversion videos, this guy does not even empty out the old electrolyte first, or rinse with distilled water, he just spoons in odd amounts of epsom salts into old sulfuric acid electrolyte as the mood takes him.

Further on in the series this becomes an advertisement for a charger he builds (and apparently sells) with an open frame out of wood and sheetrock screws, a rectifier,  a monster filter capacitor, and a wall timer, and a $2 multimeter from Harbor Freight with a bad battery (as he explains) giving false readings. His "Capacitative' charger has exposed terminals throughout, a ball of wiring, and exposed alligator clamps for the battery, which he points and will charge with an output of 130V.  :zap:

After wading through the series, which begins with recommendations that people do what he does, his experiments produce poor results. Apparently, it was still worth putting up on youtube, so others could do the same thing.
I love it when a Plan B comes together!
Steve
www.sredmond.com