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Well I have heard that, but this cell looks, feels and smells like A123... sure doesn't perform bad either. I wonder how the genuine cells perform? better, worse?
I think I know what video you are talking about, I saw the video posted on EndlessSphere forum about 2 years ago abouts. Those 20Ah cells are beasts, they say they are meant for energy applications, but the cell resistance is so low, you could use it for any application. I saw a video of a 600+ amp discharge of that 20Ah cell onto a steel flat bar, and something like 2.6 volts? If they ARE counterfeit, then I wonder what this means for cycle life, or calender life? I shall find out if I keep cycling this thing, I am nearing 100 cycles now. |
If you can't buy genuine A123 cells from online distributors, then where do you buy them?
I really want to test one of those 32157 cells |
The response I got from A123 Systems is that there is no way for an individual to buy genuine real MC Coy A123 Systems cells of any kind.
I found the video of that crazy Irish dude Damian MC Guire:yes: I thought he was testing some A123 cells but he's not. He's testing a CALB CA180 LiFePO4 cell. A big cell good for cars and trucks but not really for motorcycles or bikes. Still the testing is fun to watch. Go to http://www.evtv.me/vidarch.html Then scroll down to the July 27, 2012 video titled ''Cadillac Escalade - IT'S ALIVE! First run'' The video takes a bit of time to load. The testing starts at 4 min. 37 sec. but there's a lot of tlaking about it. The good parts I saw are at 21 min. 30 sec., 24 min. 40 sec. and 25 min. 50 sec. |
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I mean an electric bicycle. If I only hand the money to build me one. Maybe if I sold all my RC stuff........ |
Hey, I have been busy the last week, sry I haven't posted in a while. I am currently at 100 cycles on that 32113 cell, but I am currently cycling all the cells in my 52 volt (16s) 15Ah ebike battery as I thought there was a problem with some cells, but it turns out that I have too much de-ox mineral paste on the connections that it was making a high resistance point at every cell. I have been checking every cell, cycling them 3 times and they all come out as 15+Ah and 720i reports 0 mOhm for all cells.
I will get back on the 32113 cycling when I can, and make a video of different discharge loads. Snell, I would like to make a cheap electric bike conversion as well. It would be nice to use a small power pack enough for daily commute, PLUS a trailer with a gen set for long trips. |
125 cycles now and still reporting the same max 4360mah when it was new from A123rc.com. I did a few mixed discharges with 10Amps and 80amps pulsed, for a 3 min discharge. This thing might not have the best energy density but it sure is tough.
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I will post a high discharge test tonight.
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Thanks for the work you're doing here with those cells. So how many cycles are these cells good for you think? I looked at the datasheet and from what it says, they drop to 80% capacity just after 300 cycles? Or maybe I just don't understand the graphic because it doesn't really show the same thing you are experiencing after 125 cycles.
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No problem, I figured since there is no videos or discharge tests on this thing, I thought I would do a half rigged setup to cycle it and abuse it.
What datasheet are you looking at? IIRC, they are the most cycle tolerant cell that A123 makes. So far, I see 0% loss in capacity at this point, capacity loss from cycles is pretty linear graph, so I can see this thing lasting thousands... if used for a strictly power pack buffer (micro cycles) then it could last tens of thousands. I can't post that high rate discharge today like I said. BTW, I was doing a high rate discharge and forgot about it and the cell was brought down to 0.7volts. I quickly pulled the cable off and I immediately started charging at 0.4amps until it reached 3.0volts. IR check at Dschg. # 125 cycle - 1mOhm and reporting 4330mah |
All IR checks done with 720i NET charger, BULK discharges done with MIXED 720i 10amp discharge, or 13C wire constant resistance discharge, a few heavy discharges of 30C or more.
Dschg#1 - 4300mah IR check: 3mOhm Dschg#60 - 4315mah IR check: 2mOhm Dschg#110 - 4350mah IR check: 2mOhm Dschg#130 - 4340mah IR check: 2mOhm DSCHG # 131..... Discharge load 16FT of 6awg booster cable shorted Cell temp before & after: 111F - 138F Cell voltage before: 3.425v. fully charged Cell voltage on load: 3.053v. Total discharge time: 2:04 mins = 30+ C discharge = 132amps AVERAGE DISCHARGE Discharge rate would be higher than 30C at start of discharge, and lower at end of discharge. |
cool stuff man.
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I was looking at the pdf file I got from A123 Systems about those cells. See it here. Man you are beating that cell like there's no tomorrow. That is one tough cell up to now. Did you say that you brought that cell down to 0.7V and it came back up with practically no increase in IR?
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Yeah we know Bondo.
mistercrash, the only graph about 300 you are thinking about is cell level capacity vs. kWh throughput... so after 300kWh have been cycled through the cell, it is at 80% capacity. That is ALOT of energy throughput. It looks like my cell I bought is on the bottom of the cell capacity range at roughly 4.36Ah, range is 4.3 - 4.5Ah.... maybe the rejects of less than 4.4Ah are sent to resellers in China? |
I am finding this thing doesn't have a very linear cell IR, seems to hold a narrow voltage range under load regardless of discharge current. Report back tomorrow for heated discharge test, cell temp will be 170 F. :whistle:
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