Correct, the article mentions that he uses a large number (48 cells) of Lithium cells, which only makes sense if he uses them as long string of series cells, probably about 160 Volts of pack and all packs are in parallel. If you just parallel them without control, then they all discharge more or less equally, depending on internal resistance. If you control them and can discharge just one at a time, then each needs to be capable of delivering the full power, if he gets Leaf type performance which is 80kW then at 160V he needs each string to be capable of delivering 500A which is likely not what they are capable of, also seeing the Anderson connector type that he is using that typically has a max 75 Amp current capacity, as well as the typical capacity of a suitcase sized module with 48 cells indicate that he has no more than 20Ah pouch cells in there, 48 in series. If the pouch cells allow 4C discharge then that is 80 Amps of current, the max that his connectors can do. So no, unless he is limiting his power draw to ~12kW, which is barely sufficient to maintain 55 MPH steady speed on a flat freeway (I measured it) there is no way that he is discharging his modules one at a time. He may be able to discharge half of them at a time so if you expect a stop halfway and you need to get more charge to make the next hop, then it makes sense to discharge 5 modules completely and only swap those out for 5 full modules while the other still almost full modules stay in the car. 5 Modules would give in the order of 400A max discharge so that is a usable amount of power of around 60kW to be able to safely drive a car on a freeway. I have an EV that can send about 30kW to the motor and it is barely enough to safely get on the freeway, but I can manage with planning long enough in advance when to start accelerating and keeping enough space in front of me - just like a semi driver should be doing at all times.
Again, his statements do not reflect what is possible and he probably knows that, that is why he still claims that they need to figure out what works, but it is simply physics to see what is possible and what not. 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: EV [mailto:[email protected]] On Behalf Of paul dove via EV Sent: Monday, May 02, 2016 10:42 AM To: John Lussmyer; Electric Vehicle Discussion List Subject: Re: [EVDL] EVLN: ?L3 quick charging or pack swaps,on long EV trips? (v) Ok, So I looked it up to verify my statement. It looks like all the modules are in parallel. This way you can just remove one or two modules to increase the capacity of the pack. As opposed to the way everyone else does it with small voltage modules or cells in series they use high voltage modules connected in parallel. http://sygma.sdsc.edu/sites/swat.sdsc.edu.sygma/files/file_fields/article/XinIFAC2014_0.pdf From: John Lussmyer <[email protected]> To: Electric Vehicle Discussion List <[email protected]>; dovepa <[email protected]> Sent: Monday, May 2, 2016 11:55 AM Subject: Re: EVLN: ?L3 quick charging or pack swaps, on long EV trips? (v) On Mon May 02 05:22:27 PDT 2016 [email protected] said: >He says: >Imagine that now you're driving your car, and let's say its 40 percent or >50 percent empty," de Callafon said. "You would have to charge it. Here you >could actually take, if you have 10 modules in your car, and take five out ? >those are the ones that are empty ? and put five in and you're completely >replenished." >-So, he is using all the modules at once to power the vehicle. Actually, since you only need to replace SOME modules to bring the car back up to full charge, it means that ONLY those modules were used to power the car. AND since you aren't going to tell the car "Just use 3 modules for now", the car would be pulling power from 1 module at a time. -- Bobcats and Cougars, oh my! http://john.casadelgato.com/Pets -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20160502/b61d68b5/attachment.htm> _______________________________________________ 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) _______________________________________________ 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)
