Hopefully Evan will respond. Good to see he has 50k miles with no noticeable change in range. I thought I would respond since I have similar cells. The car has about 4 years and 29k miles on it as an EV (http://www.evalbum.com/3060).
/- How many of the 180AH cells do you have./ 36 cells for nominal 115V. About the max you can use with the controller I am using. /- I assume you have the Blue CALB cells./ Yes, CALB SE / - Do you know the approximate converted weight of your vehicle./ 2260 lb / - Are you using a BMS, or the Jack Rickard bottom balancing technique./ I have run bottom balanced without a bms, with a bms with HVC and LVC only and no shunts, and for the last 3 years with minibms with shunts. All work, but require different amounts of attention. I prefer my current configuration: top balanced with shunts as I find it easier to control charging, it results in less risk of overcharging a cell with regen (I have an AC motor), and I never go below 25% charge, usually not less than 35%. I think David Nelson's (Gizmo) setup will work well also - no bms but a monitor showing half pack voltages. You need some way to check how the cells are behaving. If you go this route with bottom balancing and have regen you will have to charge the pack to a lower voltage to ensure regen doesn't overcharge the lowest capacity cell, unless you use an Orion bms with interface to the controller to cut back regen if a cell goes too high in voltage (see evmetro's build thread at diyelectriccar). With the pack top balanced you can just use a parameter in the controller to limit the voltage of the pack, since all cells are close enough in voltage that none will be overcharged with this method. /- What Voltage are you charging the cells to./ I charge the pack to about 125V, or 3.47V per cell, but actual cell voltages vary from around 3.45 to 3.52V at end of charge. / - What depth of discharge (DOD) do you normally take the cells down to./ Usually 35% to 50%, never below 25%. I also have not noticed a decrease in range. My test is each year to discharge down to about 28% SoC, floor the accelerator to draw max battery current (550A, ~3C) and see if that triggers the LVC alarm on the bms. Hasn't so far. -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Range-tp4665484p4665879.html Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. _______________________________________________ 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)
