So here we have examples of how a typical bms install without prior balancing leads to ruined cells, and other people with no bms, 50,000+ miles and no trouble. The pro-bms folks to be loosing this one. I was initially skeptical of no-bms until hearing similar stories as Evan Tuer. No BMS and no issues.
However, the bigger question here is "what is a BMS?" If my controller has low-voltage cutoff, is that a bms? If my charger has a high-voltage cutoff, is that a bms? Is a bms only a bms if it uses shunts to top-balance? What about a bottom-balancing bms? If you had success using a bms then you are convinced every EV needs one. If you had success without one then you are convinced they are unnecessary. Both are right. On Tue, Apr 22, 2014 at 3:43 AM, Evan Tuer <[email protected]> wrote: > 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) > > -- Marcus Reddish -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140422/48fa8e06/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)
