I think this might help:
P.S. Biology is all greek to me.
Thanks!
Yes, my part did start with the Greeks. Aesculapius to be exact, as mentioned in the Iliad.
http://premiumcaremd.com/wp-content/uploads/2013/08/Staff-of-Aesculapius.pdf
:tongue:
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I think this might help:
P.S. Biology is all greek to me.
Most long term graphs that I've seen show capacity loss pretty much leveling off around 70%-80%
Yes I'm talking single cell graphs and normal capacity loss. I'd say allowing an excessively degraded group of paralleled cells to cripple a pack is a maintenance issue, like running with a bad spark plug.
You can still find them on eBay if you search "Sanyo 18650". Or you can go to Alibaba, but it's harder to vet what's real and what's not and probably not worthwhile unless you are buying in bulk.Wish I could replace a brick or sheet in the time it takes to replace a spark plug!
JRP3 you know a lot about where to buy cells. Suppose I had all the right tools and removed a sheet from my ESS and tried to replace the cells in a brick. Where would I buy them? Is it even possible to buy those 2200 mAh cells anywhere? Not that I plan to try this at home or anything...
Probably one of the most interesting threads on here....
I have had a chance to go over some of the logs of my 4 Roadsters and to my surprise the highest mileage one (22k miles) has the highest CAC. The others have 1/10th to 1/5th the amount of mileage as the one with 22k miles but are almost always charged on a 70A or 40A. I religiously charge the high mileage one on 110v and have had great results (192 ideal miles after a full balance). This could be just luck of the draw but it is interesting nonetheless. Would love to see some data for charge rates and how they relate to battery longevity.
Another possibility is to use a higher amp hour cell. Since balancing takes place at the top of SOC those cells will simply never be as deeply discharged and the BMS shouldn't notice any difference. As long as the finish voltage of the cell chemistry is the same as the rest of the pack it shouldn't matter.Wish I could replace a brick or sheet in the time it takes to replace a spark plug!
JRP3 you know a lot about where to buy cells. Suppose I had all the right tools and removed a sheet from my ESS and tried to replace the cells in a brick. Where would I buy them? Is it even possible to buy those 2200 mAh cells anywhere? Not that I plan to try this at home or anything...
It may be that the more frequently cycled Roadster simply gives the BMS more opportunities to balance the pack.I think its just a coincidence or just by chance that the BMB managed the higher milage Roadster better and possibly mismanaged the lower miles Roadsters.
This is exactly what we have seen on here with roadster packs. 110V charging balances the battery better, and therefore you get a higher CAC, and ideal range. From my experience, my model S is following this same exact path(I charge it on 120V a lot).Probably one of the most interesting threads on here....
I have had a chance to go over some of the logs of my 4 Roadsters and to my surprise the highest mileage one (22k miles) has the highest CAC. The others have 1/10th to 1/5th the amount of mileage as the one with 22k miles but are almost always charged on a 70A or 40A. I religiously charge the high mileage one on 110v and have had great results (192 ideal miles after a full balance). This could be just luck of the draw but it is interesting nonetheless. Would love to see some data for charge rates and how they relate to battery longevity.
Who at Tesla said this?Tesla say's that if you charge off of 110V it doesn't give the pack to properly balance and recommend 240V at 20+ Amps.
Yes. Using higher amp hour cells would just make each ideal mile last longer.Another possibility is to use a higher amp hour cell. Since balancing takes place at the top of SOC those cells will simply never be as deeply discharged and the BMS shouldn't notice any difference. As long as the finish voltage of the cell chemistry is the same as the rest of the pack it shouldn't matter.
Who at Tesla said this?
I can see the partial charges being an issue, but as long as you do a standard/range charge every once in a while, cannot see the drawback of charging on 110, other than a slightly higher electric bill.The service manager @ Menlo park.
Is it true what he said? I don't know but he did imply seeing Roadsters which have been charging off of the 110V circuit are typically out of balance. Possibly people are doing partial charges and the SOC is below 80% since 110v is very slow. Personally I don't see a difference with the balancing as long as the Roadster gets 30 min to 1 hour to balance after an 80%+ SOC charge.
Another possibility is to use a higher amp hour cell. Since balancing takes place at the top of SOC those cells will simply never be as deeply discharged and the BMS shouldn't notice any difference. As long as the finish voltage of the cell chemistry is the same as the rest of the pack it shouldn't matter.