On a sunny day (Mon, 28 Jul 2014 08:16:37 +0100) it happened Charlie+ wrote in :
Yes I am testing much the same way, but with lower current, and a stopwatch. I had 18- seconds before the 200 mA @ 16 V method. and now 25+ seconds after using that method for some weeks.
Hope this pulsing helps, if not I will try that AC variac method... Do not have the variac, but a 300 W audio amp with several transformers and PC as signal generator. Fun :-) Looking forward to it :-)
Here is my pulse charge impulse;
formatting link
5V / div. The top is at 17.5 or so.... 15 kHz epetition rate. Some voltage drop over the cable, not measuring directly at battery terminals.
Please note that NiFe-accumulators has high internal resistance compared to Lithium Iron Phosphate (LiFePO4).
-
Have you tried Edisons NiFe-accumulators?:
Oct 15, 2013, NiFe Batteries Said to Outperform VRLAs:
formatting link
"... When energy available over the entire cycle life of a battery is considered, the Atlas 160 product cost is one-tenth that of a lead acid battery with similar name plate capacity. ..."
formatting link
formatting link
formatting link
Citat: "... Battery Cycle Life 11,000 cycles Battery Life on Float 30yrs. Battery Storage Life 85yrs ...
...
..." Iron Edison USA Series Nickel Iron (NiFe) Battery:
formatting link
Citat: "... This battery is rated for 10,000+ cycles at 80% Depth of discharge. ... Optional integrated watering system ? makes maintenance fast and easy ..."
formatting link
Citat: "... Have Conducted Extensive Abuse and Accelerated Life Testing for 2 Years ... Encell Proprietary and Company Confidential ..."
formatting link
-
ironedison.com probably bought from:
formatting link
formatting link
NiFe producers:
formatting link
-
-
-
Now LiFePO4:
Baffled by batteries? CHOOSING THE RIGHT BATTERY:
formatting link
Lithium Iron Phosphate (LiFePO4) and A123 batteries:
formatting link
Quote: "... Imagine if we could combine the safety and durability of nicads with the capacity and light-weight of LiPos. Wouldn't that be the best of all worlds?
Well that's pretty much what you get with the latest battery technology known as Lithium Iron Phosphate (LiFePO4).
Batteries based on this technology have almost the same power to weight ratio as LiPos but are far more tollerant of over and under-charging.
In a situation where a LiPo might explode into flames, the LiFePO4 cell will probably just vent some harmless gas. ... The capabilities of an A123 battery are truly impressive -- with a
2300mAH pack being able to deliver currents of up to 100A for 10 seconds or more without damage. That's a 40C rating.
A standard LiFePO4 battery by comparison, may have only a 3-5C rating which is perfectly adequate for most RC applications but nowhere near as suited to hi-current applciations (such as electric power) as a true A123. ..."
lifebatt.com: Sandia report:
formatting link
formatting link
Citat: "... Test results have indicated, that the LiFeBatt battery technology can function up to a 10C discharge rate with minimal energy loss compared to the 1 h discharge rate (1C). ..."
Rick's Pic based Lead Acid battery pulser / desulfator V0.5 page:
formatting link
Lead Acid Battery Desulfation Pulse Generator Some help and information for builders:
formatting link
Chapter 10: Getting the Most from your Batteries:
formatting link
Lead Acid Battery Desulfation:
formatting link
The truth about desulfation:
Penn State (2013, January 4). Researchers seek longer battery life for electric locomotive. ScienceDaily:
formatting link
Quote: "... "We wanted to reverse the sulfation to rejuvenate the battery and bring it back to life," said Christopher Rahn, professor of mechanical engineering. ... "We desulfated it, and we increased its capacity," said Rahn. "We didn't increase it all the way to brand new. We weren't able to do that, but we did get a big boost."
The researchers increased the cell capacity by 41 percent and the overall battery capacity by 30 percent. Even better results might have occurred if sulfation were the only aging mechanism at play, but the researchers found other factors reduced capacity, as well. ..."
On a sunny day (Mon, 28 Jul 2014 12:36:03 +0200) it happened Glenn wrote in :
Yes I have a model airplane, 'Laser Arrow' that has same Lipo. Those guys make mistakes. You always need a very big pliers at hand to take out lipo if it burns....
So far no explosions here. Vertical takeoff:
formatting link
I have tried to make it hover, no luck so far...
Here a similar one in action:
formatting link
So far I have added GPS, multiple way points, enemy target tracking, FPV with Sony starlight camera (night flight), some other top secret stuff. Mainly use it to bring diamonds across the border ;-) PICs, some of the soft is on my site. Video down link is at 5 GHz,
Yes, sorta. I've had lousy luck with pulse desulfaters. What seems to happen is that chunks of lead fall off the mesh along with the lead sulfate (PbSO4). From the literature, I could not find any evidence of chemical action in the process, so I guessed(tm) that what was really happening is that the pulses were shaking the plates causing the brittle lead sulfate to fall off. I just happen to have a paint shaker available, so I put the failed batteries (wet cell and gel cells) in the paint shaker with the terminals pointing up, and let it vibrate for about 10 minutes. That destroyed several cheap automobile batteries when the plates fell apart, but managed to partly rejuvenate
3 out of about 8 or 10 UPS batteries, which were a mix of gel and AGM batteries. I think it worked for gel, but not for AGM. I suspect that the reason the shaker didn't work for AGM batteries is that the glass matt mesh traps the lead sulfate. The 10 minutes is arbitrary and probably not optimum. I ran a discharge test with my West Mtn Radio CBA-II on one of the paint shaker rejuvenated 12v 7A Panasonic gel batteries, which shows about 60% of normal capacity and a higher than normal self discharge rate. It ran my home UPS for an additional
2 years before I declared it dead (again).
Obviously more work is needed for this method. As I see it, the problem is that when the lead sulfate breaks off, it doesn't just settle to the bottom of the battery tank as it would with a deep discharge wet cell battery. To make that happen, I think a centrifuge might take care of transporting the lead sulfate to the bottom. Even so, there's no space in a gel cell for the lead sulfate to collect. By concentrating the conductive lead sulfate at the bottom, near the ends of the plates, I may have made the problem worse. The only way to know is to do an autopsy on a paint shaker and centrifuge treated battery and see what's really happening inside. Since I don't believe anyone would actually for a machine to automate the process, I haven't bothered.
Also, try to charge the battery BEFORE shaking. The idea is to get as much lead out of solution and back on the plates to strengthen the plates so that they survive shaking. I think that's what killed the wet cells as I shook them in a discharged condition with little lead on the plates.
Now that I've almost mastered raising the dead (battery), I'll work on the walking on electrolyte part. Good luck.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Not always. Sometimes the telcos donate the batteries to a worthy recipient, like our local ham radio club: I think these were donated by Pacific Bell in about 1990. They are a little low in voltage and capacity, but otherwise ok. Not bad for 25 year old batteries. I have no idea what are the current policies on battery recycling or donation.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
On a sunny day (Mon, 28 Jul 2014 08:14:43 -0700) it happened Jeff Liebermann wrote in :
Thank you, yes I noticed somebody else who did shake the batteries but I think once the sulfur is at the bottom they say it will no longer react.. They say then the battery is dead. Mine is still running on pulse now, in a few weeks? I will do a capacity test again. If this did not help I will try Robert Bear's method. Also I have, at the same time, some light bulb doing discharge (between pulses), somebody wrote that helps. It is just experimenting really...
Good to know. I thought I was the only one insane enough to try it.
Sorta. When a wet cell battery is discharged, lead sulfate is in the electrolyte solution. When recharged, you get metallic lead on the negative plate, and lead dioxide on the positive plate. On a dry charge battery, the manufacturer smears lead sulfate paste on the terminals. It's not like lead suflate is some kind battery poison. The problem is that solid lead sulfate can end up on the wrong place in the battery, like between the plates, causing a short circuit. What the various pulse electrical removal techniques do is try to break loose these shorts and hopefully have the lead sulfate drop to the bottom of the tank. The problem is that the lead sulfate contains lead needed to replate the plates, which is not going to happen if the lead is locked up as a solid on the bottom of the tank.
Note the large gap between the bottom of the plates and the bottom of the tank in 'DEEP CYCLE BATTERY CONSTRUCTION' exploded view.
His series capacitor and AC power method seems like a variation on the shake method, but running at 60 Hz instead of a much lower frequency in the paint shaker. I think I can transfer more energy with the paint shaker, but I'm not sure.
I would be interested in the results and your conclusions.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
One method I read about suggests that the drive frequency should match the mechanical resonant frequency of the plates to maximize shake. Stick a microphone on it and vary the frequency for max sound.
It's the view from the automobile battery perspective, but does include quite a bit on other types.
The section on sulfation gives important clues on what is happening. When a discharged battery starts to precipitate out lead sulfate, it starts by filling in the holes in the lead sponge plates. The sponge plate pores gives a larger surface area for the battery and therefore higher peak current and more capacity (Amp/hrs). Plug up the pores, and the battery capacity would be about the same as solid lead plates. Once the holes are plugged, the battery can work on precipitating lead sulfate on the surface of the plates, where the reduction in plate surface area has a much bigger effect on battery capacity. Eventually, the accumulated lead sulfate becomes large enough to short the plates, causing catastrophic self discharge and associated heating.
When rejuvenated or resurrected by various magical means, the surface lead sulfate is probably removed and hopefully the shorts removed. However, the lead sulfate that was initially plugging the holes in the lead sponge plates is probably permanent, resulting a functional, but nowhere near full capacity battery.
I've noticed that heavier batteries last longer than light weight battery of the same rated capacity. The common 12v 7A-hr UPS gel or AGM battery come in an odd range of weights. I like to buy the heaviest, which commonly is the most expensive. My guess(tm) is the heavier battery has more lead, smaller pores, and/or larger surface area. It takes longer to fill the pores in such a heavy battery than a light weight battery, so therefore it takes longer for sulfation shorts and self-discharge problems to appear.
How to get the lead sulfate out of the pores? You don't. Instead, you use a "deep cycle" battery that uses non-sponge lead for plates. You get lousy capacity and peak current (peak cranking amps) but much less sulfations and much longer life. You also get a much heavier and more expensive battery. The problem is that the buzzword "deep cycle" has been attached to all manner of batteries which do not deserve the label. Look for the heavy weight, price tag, and sump at the bottom to catch the lead sulfate droppings. Caveat emptor.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
I beg to differ. You do NOT want the plates flexing. They will break. If you tune for resonance, the plates will probably move sufficiently to break somewhere, probably near the supports at the top of the cell. The battery is made to handle substantial G forces, but little flexture because it is assumed that everything inside moves together. What methinks one wants is to produce a sloshing action of the electrolyte or gel, that mechanically pushes the accumulated lead sulfate off the surface of the plates.
Now, if I really wanted to clean the lead sulfate out of the pores in the plates, I would probably want cavitation. However, I'm not about to pour soap into the battery and hammer it with ultrasonics. Exploding bubbles have plenty of force, but on the scale of a car battery, I think it might be a bit much for a kitchen experiment.
Incidentally, exposing the lead plates to the air produces lead oxide. Mix that with sulfuric acid and you get a nice coating of more lead sulfate. This is why keeping the electrolyte level in a battery is important. It's also probably why pouring the electrolyte out of a wet cell battery, replacing it with water and soap, and doing the ultrasonic thing, may not to work very well.
Learn by Destroying(tm) and I have the hot acid burn mark on my Formica workbench to prove it.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
They're what the top brand power tool mfgrs use, DeWalt etc. I did a refit using cells from Hobby King. They warn that a lot of dodgy outfits are selling repackaged basically dead cells, so beware. My refit works well.
In one of your pictures there is a bare wire soldered to the positive terminal and routed down over the edge of the cell. That is a dangerous condition as the only insulation is the green plastic shrink wrap over the cell. If it breaches, it will directly short out the cell with lots of fun to follow.
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.