I am hoping others that are more knowledgeable than I will post or contact you directly on this. But you do not give details that help define where your low-budget money is to be spent.
Detail on your EVent: http://targa.com.au/tc/page_full.asp?asset_id=1637 2013 Targa Tasmania Course http://www.swadeology.com/2013/04/targa-tasmania-gallery-and-awards/ 20% down the page shows http://www.swadeology.com/wp-content/uploads/2013/04/DSC_4214.jpg Datsun 1600 Targa Tasmania Please try to give the details on: -What model 1970's Datsun (truck, sedan, a Z?) -Define what is "enough performance"? (300VDC, 144VDC?, how much horsepower is enough?) -How many km/miles between pack swaps is enough?, etc. Using a search engine to look at Datsun's on evalbum.com gives trucks, sedans, Z's. But the most significant Datsun racer is John Wayland's. http://www.evalbum.com/35 1972 Datsun 1200 “White Zombie” http://evalbum.com/36 1972 Datsun 1200 “Blue Meanie” I have a couple pics of when he was racing (his configuration has change since these were taken): http://brucedp01.150m.com/lvnedra01/lvnedra01-06.jpg http://brucedp02b.150m.com/woodburn02/020901-113.jpg If you are using a similar Datsun sedan, perhaps a rear pack, where a lift mechanism could be fabricated to slide in under the pack from the rear (pack in the trunk area), to remove and replace the spent pack. Alternative: When John raced his EVs on the drag strip, he would use a dump pack arrangement (one higher voltage pack, transferring to the non-removable on-board pack) http://brucedp01.150m.com/lvnedra01/lvnedra01-12.jpg He was using agm batteries to dump from, and as the evalbum pages show, to an agm on-board pack. He started out at a lower voltage (not as many batteries in series), and incremented the voltage as the on-board pack's SOC increased. Starting out his transfer currents were high and quickly dropped down. He would disconnect the dump charge to add another battery to the string to bump the dump pack voltage up, and keep the DC transfer current high. This minimized the time spent dump-charging, and maximizing the time spent racing during the day. At what point he bumped the dump pack's voltage by including another battery in the string (he moved the jumper cables around) came with experience (it was a low-cost manual process) During the waiting period of being in line to race, the time used racing, and the time to get back to the pit, the dump pack was recharged using a (6kW ?) genset. The on-board agm pack with higher performance agm batteries, and the dump pack was made up of lower-cost agm batteries. AGM batteries cost less than li-ion. The way John used the on-board pack was like the way an ice- racer over extends their ice (over red-line) to get the most out of it. He would quickly recharge, and as the on-board pack heated up from repeated charges/uses, he got better/lower drag race numbers. Steaming the on-board pack was not the way to save agm battery life, but that was not his goal. John stated that when his on-board pack was beginning to steam (losing precious electrolyte that can not be replenished like a wet-cell battery), is when he knew he would get the most from that on-board pack. In the same way, an ice racer would plan to tear down & rebuild his ice after a race, John would know how many races he could get out of his (expendable) on-board agm pack, before replacing the entire on-board agm pack. {brucedp.150m.com} - On Thu, Jul 18, 2013, at 02:10 AM, James Massey wrote: ... > I have been invited to assist in the build-up of a vehicle that will > be entered in Targa Tasmania (road-rally touring race), at present I > have very little information, but as it stands their plan is: 1970s > Datsun (he mentioned the model, but I forget already). They have the > cage in the car already, and continue to prepare the non-EV systems. > DC motor, lithium batteries. > > At this point the plan all became a little vague, other than they > plan on using large-format cells, Thunder-Sky or similar. > > I'm leaning towards recommending they use a battery-swapping > arrangement, two or three lighter packs and one or two swaps instead > of one larger pack, as Targa includes some significant travel stages > as well as the race stages. a "refuel" at the start of the race > stages coupled with a lighter pack could be significant. > > Open to all ideas and opinions, but keep in mind that they are a > low-budget race team, so looking for enough performance with minimum > dollars spent, rather than maximum performance. - -- http://www.fastmail.fm - The professional email service _______________________________________________ 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)
