I don’t know what Lee drives but the loss in the I-MIEV is not near that high maybe 10% or so. It heats a fluid for cabin heat and this uses power very fast. Would not work in my car
Sent from my iPhone > On Sep 10, 2019, at 3:45 PM, Peri Hartman via EV <[email protected]> wrote: > > I'm really surprised the "balance" is so poor. If the battery has reasonable > insulation, how much power would it take to keep it warm - e.g. 50F - for, > say 8 hours ? Let's say the outside temp is 0F average. > > I don't expect anyone to do calculations. But Lee gives an approx metric of > 30-40 miles when cold and 60-70 miles when the battery is 50F, both with 0F > temp outside. It seems fair to surmise that the difference in range is due to > the temp of the battery. For the 2013 model, I think it has a 30kWh battery. > That means that roughly half of the battery's kWh is not usable when the > battery is at 0F, or about 15kWh. Really, for an insulated battery, it would > take that much energy to keep it warm while you're out doing something ? > > Let me give a real life example. Let's say I buy a Bolt and want to use it to > go skiing. It's 160 miles RT. The average temp while at the ski area parking > might be 25F (hopefully not 0 :). I want to be sure I can get home without > stopping to charge somewhere. If I can heat the battery while skiing, I > should have no problem. If not, I'm probably ok in this scenario, but not > with too much margin. (A lot of hand waving calcs going on, I know.) > > For this wave of early adopters, it's not that big a deal. My guess is that > there's virtually no insulation and the manufacturers are skimping because it > won't matter so much to the current buyers. But if the manufacturers want to > sell mainstream, I think this will come back as a serious red flag for many > buyers. Of course, in the mean time, we're getting better technology... > > Peri > > ------ Original Message ------ > From: "Robert Bruninga" <[email protected]> > To: "Electric Vehicle Discussion List" <[email protected]>; "Peri Hartman" > <[email protected]> > Cc: "Lee Hart" <[email protected]> > Sent: 10-Sep-19 12:05:06 PM > Subject: RE: [EVDL] li ion battery in cold weather > >>> Ok, then why don't battery heaters - which I thought the Bolt & Tesla >>> have - give a good winter range ? >> >> Because there is a balance temperature point above which you are burning >> more kW just warming up the battery than you get in better range for the >> same kWh.. In either case range in winter is less because the battery is >> cold or you are using up kWh for warming the battery. Either way, reduced >> range. >> >> bob > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/index.html > INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) > _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
