Evan, can you open a bit that 50.000 mile cycles? How shallow or deep cycles you take?
"Overcharge" balancing was showcased in China already in 2006 or so. It works but kills cells. Check what yout voltages are at EOC. This would help us to understand your special conditions and success. Also there are chemical additived to activate shuffling when voltage threshold is met. This could be something CALB is using. It can add self discharging. Or maybe you have been able to get good pack and BMS did good job on the 1st years. Is it an agreement cells do not eventually die? Or when they do it's always happening with noticeable increments without any chance for accident? When BMS fails it should render further damage impossible/unlikely to occur. Many designs are drawing energy from cells even when off. That is bad idea. There is alot of shit for BMS. If you look at the statistics how many trips are done in car without collision and then in how many collisions there was any difference if seat belts were on or not. Can you still argue seat belts are not smart to have? BMS is there to deal with many variables and with accurate measures. It's the seat belt. -Jukka 22.4.2014 12.44 kirjoitti "Evan Tuer" <[email protected]>: > My experience differs. I have CALB 180AH blue cells in my car, which has > covered more than 50,000 miles in about 4 years. I haven't looked at the > pack once since installing it. I had a self-built BMS monitoring the pack > to start with, but it got water damaged and I never got around to fixing > it, so for the last 2 years the pack has looked after itself (effectively > it's been "top balanced"). > > > On Mon, Apr 21, 2014 at 12:05 AM, Cruisin <[email protected]> wrote: > > > After selling CALB cells for over 5 years and using them in my own > > conversion, I can tell you from experience the following. At least 15% of > > the cells will change so much in the first year the BMS will react to > your > > disadvantage of early charging termination and early over discharging. A > > one > > year warranty that is promised is hocus. the second year will experience > a > > 10% failure with no warning of a cell. This makes your car unusable. > > Further > > experience with other Chinese cells is no better, or worse. I now sell > and > > use the Nissan Leaf module that is half the price and so far no failures > > like the CALB. I would not ever recommend a CALB cell to any customer. > > Those > > that are pushing the cells like EVTV have inventory they want to unload > > before their is no more demand for Chinese cells. My customers who have > > converted to the Volt and Leaf cells, made by the same S Korean > > manufacturer, are really happier with the results. No more stagnant at > rest > > loses that you have experienced. Look at what cells are used in the > popular > > plugin cars that are required to provide a 8 year warranty in California, > > no > > Phosphate. CALB would be out of business if required to provide a 8 year > > warranty. They don't even recognize their one year warranty. You wonder > why > > you are having problems, wake up and smell the coffee. > > > > > > > > -- > > View this message in context: > > > http://electric-vehicle-discussion-list.413529.n4.nabble.com/self-discharge-of-CALB-180Ah-LiFePO4-cells-tp4669067p4669069.html > > Sent from the Electric Vehicle Discussion List mailing list archive at > > Nabble.com. > > _______________________________________________ > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > For EV drag racing discussion, please use NEDRA ( > > http://groups.yahoo.com/group/NEDRA) > > > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140422/72edaa01/attachment.htm > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140422/717f4241/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
