Back in 1976, The estimate range was calculated by the following method by Robert Aronsson CEO of Electric Fuel Propulsion Co. where I received my first EV call Transformer I which I still drive today. Bob Rice work at EFP at the time.
In a new battery pack, drive it at least to 50% DOD for about 50 cycles which increases the plate area allowing current to flow deeper into the cell plates. This is what is call the battery break in or conditioning. Next, After charging the battery pack to 100% at the ideal battery temperature, record the resting voltage and specific gravity if it's a lead acid battery. Drive the EV for five miles at a level grade at the same speed and temperature and record the resting voltage and SG again. If the battery pack new, torque the battery links. It is very common for the first series of 5 miles drives, the link torque may loss about 5 inch lbs. Run a graph of the voltage and distance travel until you reach the minimum voltage you want to establish. As the battery pack ages, you can record the diffusion time constant and voltage drop. Drive the EV for one minute and record the time it takes for the battery voltage recovers to its resting voltage. Then drive it again for one minute and record the data again. Graph the diffusion time and voltage recovery. The curved will then give you a estimate of range. Type in your search engine - Battery Diffusion - and there are several WEB sites that will show you how to do this method. There is also a instrument that calculates the range using the diffusion data. All I need is a another meter and indicator on my dash which is now going over 42 units. Roland ----- Original Message ----- From: Bill Dennis via EV<mailto:[email protected]> To: 'Electric Vehicle Discussion List'<mailto:[email protected]> Sent: Thursday, May 08, 2014 8:43 AM Subject: [EVDL] Miles Remaining Lee wrote: >But suppose you want to know how far you can go at a given speed (i.e. a given load). >That is a much more complex calculation I rented a Leaf recently, and I really don't like the "miles remaining" thing. It varies too much. If you're going uphill, it gives a smaller number of miles remaining. Then when you get back on level ground, miles go back up. Going downhill it changes again. Talk about range anxiety. I'd much rather have just as Empty-Full gauge as a regular car does. Then I can see just how fast the gauge is going down and estimate for myself. I think most people who have driving ICE cars all their lives have the same instinct. The "miles remaining" is only a rough estimate anyway, just like the rough estimate I'd make by looking at the Empty-Full gauge. I'd be interested to hear other people's take on it. Bill _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub<http://www.evdl.org/help/index.html#usub> http://lists.evdl.org/listinfo.cgi/ev-evdl.org<http://lists.evdl.org/listinfo.cgi/ev-evdl.org> For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/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/20140508/afdb0b12/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)
