Paul, Every time the cell is at the top of charge, it will expand. Don't compress and you will likely burst it in short order. I have taken apart packs that were used *with* the Leaf BMS so charging has always kept them under 4.115V max but when I remove the nuts that hold a stack in compression, I cannot get the nuts back on unless I use heavy clamps to compress the stack back to original size. If Nissan was happy to add heavy steel end plates to an EV that needs to be as light as possible, just to keep the modules compressed, then who am I to decide that I should omit those? But don't take my word for it, try it yourself. And let us know how you fare.
BTW, I have seen what happens to modules that are overcharged to 4.3 Volts. Even with the heavy compression, some cells managed to generate enough pressure to buckle some of the module walls and the guys that took the pack apart had to make sure they were not in the line of "fire" when they undid the nuts of the end plate - nut and wrench went flying! At the normal 4.115V max, this excess will not happen, but the pressure can easily be enough to damage the thin module sheet metal walls that are not design to contain pressure, only to keep the cells aligned. You can also pull the bus bars off the cells due to the working of the stack of cells when uncompressed. Take your chances or follow the Nissan design, it is your own choice and your own quality of work. Regards, Cor van de Water Chief Scientist Proxim Wireless office +1 408 383 7626 Skype: cor_van_de_water XoIP +31 87 784 1130 private: cvandewater.info http://www.proxim.com This email message (including any attachments) contains confidential and proprietary information of Proxim Wireless Corporation. If you received this message in error, please delete it and notify the sender. Any unauthorized use, disclosure, distribution, or copying of any part of this message is prohibited. -----Original Message----- From: paul dove [mailto:dov...@bellsouth.net] Sent: Saturday, September 03, 2016 12:46 PM To: Cor van de Water; Electric Vehicle Discussion List Subject: Re: [EVDL] Alternatives for Golf Cart and Forklift batteries > Lithium stack to the frame of the lift, you are aware that the Leaf > cells (and probably other Li cells as well) must remain under > compression or risk bursting the cell pouches open, inside the modules? I don't believe that at all what proof do you have the cells need to be compressed? A cell should only expand when it's damaged. _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
