Ummm, actually you failed to ask a question... The principle behind what you are talking about is that in an EV Volts X Amps is equal to Power (Watts) and it requires a certain amount of power to maintain a certain speed. If you drop the voltage of your pack it will then require more amps to maintain the same speed. In this case, it takes 85 x 120 = 10.2 kw to drive 55 mph. If you lower your pack voltage to 70 then 10200 / 70 = 145.71 amps to maintain 55 mph.
This is the straight math. There are other factors involved as well. Can your overall system maintain 70 volts at 145 amps. My guess is that it can because most of the components that people build EVs with work fine in this range, but it is generally harder on all of your components. Without more specifics that is the best I can answer your implied question. Damon Damon ________________________________ From: EV <ev-boun...@lists.evdl.org> on behalf of ken via EV <ev@lists.evdl.org> Sent: Thursday, September 13, 2018 11:18 PM To: Electric Vehicle Discussion List Cc: ken Subject: [EVDL] decreasing pack voltage I have a 85 volt system that draws 120 amps at 55 mph, but want to lower my pack count (I found brand new cells ) but to do only top speed of 40 mph . at 40 mph my voltage is 70 volts and 40 amps, Am i asking a oboius ? the cells are 70 ah . _______________________________________________ UNSUBSCRIBE: https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.evdl.org%2Fhelp%2Findex.html%23usub&data=02%7C01%7C%7C95d6bc500de44a4d03b208d61a09f33a%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636725027361552683&sdata=Q%2Bs3sACO0XmugvJaLq6Z%2BnOZETq5XyaRU2g3q4zpNRg%3D&reserved=0 https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.evdl.org%2Flistinfo.cgi%2Fev-evdl.org&data=02%7C01%7C%7C95d6bc500de44a4d03b208d61a09f33a%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636725027361552683&sdata=ZyYpltnHO%2BQNs9SdcJlIF5Z08nnon4Vu9ViJcLnxmQ8%3D&reserved=0 Please discuss EV drag racing at NEDRA (https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fgroups.yahoo.com%2Fgroup%2FNEDRA&data=02%7C01%7C%7C95d6bc500de44a4d03b208d61a09f33a%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636725027361552683&sdata=FxLPkagjqBQ%2B4xJz%2Fy8ZDgQPRaoJNcF8YlcaLl44cHs%3D&reserved=0) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180914/a75625d2/attachment.html> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
