A couple of photo-sets that show the kind of crazy things that we do in Bristol -- just for fun, of course! Firstly, we have some shots of Russ and Nikki fitting new wheel bearings in a City-El:
http://www.flickr.com/photos/anachrocomputer/sets/72157604028399531/
And now one that's a whole lot more hazardous, sawing open a (duff) lithium-ion cell. Kids, don't try this at home:
http://www.flickr.com/photos/anachrocomputer/sets/72157604409956712/
Lithium-Ion Cell and City-El Bearings
-
- Posts: 120
- Joined: Thu May 24, 2007 9:17 pm
- Location: Bristol, UK
- Contact:
Lithium-Ion Cell and City-El Bearings
1994 Suzuki Cappuccino
1992 Mini-El electric bubblecar
1992 Mini-El electric bubblecar
-
- Posts: 38
- Joined: Wed Apr 30, 2008 5:03 pm
- Location: Bristol, UK
Interesting to inside one of these LCPs. I have a set of 7 90Ah ones - no intension of sawing them open yet though. What do the materials look like? Can you take it apart further and see the individual plates? What is the history of the cell, how long did it last and how did it fail?
Is the electrolyte like an oil?
Presumably there is no way to rejuvenate the cell with fresh electrolyte or something.
Doesn't look that complex and therefore expensive construction. Much the same as wet Nicad. One wonders where the cost is.
Is the electrolyte like an oil?
Presumably there is no way to rejuvenate the cell with fresh electrolyte or something.
Doesn't look that complex and therefore expensive construction. Much the same as wet Nicad. One wonders where the cost is.
- retepsnikrep
- Posts: 1387
- Joined: Sat May 26, 2007 4:50 pm
- Location: North Yorkshire England
- Contact:
Looks like a few layers of interleaved electrolyte/plates and seperator from the photo.
Agreed doesn't look that expensive, but don't forget if we tried to build them here H&S would mean we neded facilities akin to the uranium enrichment processing facility at Sizewell B before we could start, whereas in China some little old bloke sitting on a stool in his front room with a pair of marigolds and a face mask (if he's lucky) is putting them together for us! His Mrs will be in the kitchen mixing the electrolyte in the magimix/wooden bowl as well.
Agreed doesn't look that expensive, but don't forget if we tried to build them here H&S would mean we neded facilities akin to the uranium enrichment processing facility at Sizewell B before we could start, whereas in China some little old bloke sitting on a stool in his front room with a pair of marigolds and a face mask (if he's lucky) is putting them together for us! His Mrs will be in the kitchen mixing the electrolyte in the magimix/wooden bowl as well.
Last edited by retepsnikrep on Wed May 14, 2008 1:01 pm, edited 2 times in total.
Regards Peter
Two MK1 Honda Insight's. One running 20ah A123 Lithium pack. One 8ah BetterBattery Nimh pack.
One HCH1 Civic Hybrid running 60ah A123 Lithium pack.
Two MK1 Honda Insight's. One running 20ah A123 Lithium pack. One 8ah BetterBattery Nimh pack.
One HCH1 Civic Hybrid running 60ah A123 Lithium pack.
-
- Posts: 120
- Joined: Thu May 24, 2007 9:17 pm
- Location: Bristol, UK
- Contact:
I should explain a bit more about the lithium-ion cell. The oil-like fluid that we drained out was not an electrolyte, and the "plates" that you can see are not the actual working parts of the cell. I think the oil was either an electrical insulator, a heat conductor, or a way to keep water out of the cell.
The "plates" are plastic-wrapped units with two foil electrodes coming out of them. The foils are stacked up and bolted to the sides of the cell's terminals. So, it looks like what we have is a stack of thin, sealed cells connected in parallel and surrounded by a fluid, in a white plasic box.
As for the costs, I understand that the actual plates/electrodes unside the plastic packets must be manufactured in a multi-step process. Unlike, for instance, lead plates for a Plante cell which are little more than two pieces of lead, dipped in acid. The time taken to go through all the manufacturing steps in a lithium-ion cell is one reason for its cost.
Will attempt to cut the box open lengthways and investigate further!
PS: granada203028, if you're in Bristol, do let me know if you want to see the thing in person! And smell it...
The "plates" are plastic-wrapped units with two foil electrodes coming out of them. The foils are stacked up and bolted to the sides of the cell's terminals. So, it looks like what we have is a stack of thin, sealed cells connected in parallel and surrounded by a fluid, in a white plasic box.
As for the costs, I understand that the actual plates/electrodes unside the plastic packets must be manufactured in a multi-step process. Unlike, for instance, lead plates for a Plante cell which are little more than two pieces of lead, dipped in acid. The time taken to go through all the manufacturing steps in a lithium-ion cell is one reason for its cost.
Will attempt to cut the box open lengthways and investigate further!
PS: granada203028, if you're in Bristol, do let me know if you want to see the thing in person! And smell it...
1994 Suzuki Cappuccino
1992 Mini-El electric bubblecar
1992 Mini-El electric bubblecar
Very interesting. I'd guess the main reason for filling the cells with oil would be to conduct heat to the casing. If these are made up of smaller cells connected in parallel it says something about the need for balancing; either that parallel strings are self-balancing, or that they balance sufficiently well for the manufacturer not to worry about it.
Edit: Just realised how daft that sounds. Of course parallel strings are self-balancing, since they're at the same voltage. Making up large cells from parallel strings of smaller cells must mean a higher risk of quality problems though.
Edit: Just realised how daft that sounds. Of course parallel strings are self-balancing, since they're at the same voltage. Making up large cells from parallel strings of smaller cells must mean a higher risk of quality problems though.
Who is online
Users browsing this forum: No registered users and 10 guests