On Sat, Aug 1, 2020, 23:46 John Lussmyer via EV <[email protected]> wrote:
> Comments on multiple postings... > > On Sat Aug 01 20:34:51 PDT 2020 [email protected] said: > >I wouldn't recommend using the Nissan Leaf busbars in pack locations that > >exceed 114 amps. The bars should be fine within the series strings, which > >is what I meant in my prior reply. The ends of each of the 5 parallel sets > >should be connected some other way. > > Note that with 5 modules in parallel - it's not JUST the between-groups > busbar that gets hi-current. The next busbar down will have 4/5 of the > current, etc.. > Maybe we are using different terminology? I am calling the Leaf's module to module jumpers busbars. I am recommending that within a single series string of 17 modules per your plan that you can use Nissan busbars and limit things to 114 amps per string. I am not recommending using the same Nissan busbars to parallel one string to the next. Leaf has 2 parallel strings. I have not looked to see how those strings are paralleled. > On Sat Aug 01 19:34:12 PDT 2020 [email protected] said: > >> stack several of them for the 5p17s pack > > > >because layering up multiple short busbars to parallel the modules > >will result in a large number of junctions between the busbars, > >resulting in even more resistance and a lot of clutter on the terminals. > > True, that is a problem. > > >The only purpose for the stock Leaf busbars was to tie the middle > >terminals of the paralleled modules together. > > Why would you bother doing that? All the center terminals are good for is > voltage monitoring to detect a module that is half-failing. Tieing modules > together there will just make it impossible to detect a problem - and > provide X times more power to dump through a failing cell. > > On Sat Aug 01 20:23:44 PDT 2020 [email protected] said: > >Gen 1 Leaf is rated at 80 kW. Pack is 96s2p. Leaf modules have 4 cells in > >each (48 modules x 4 cells each=192). > > > >Voltage is 96x 3.65 V=350.4 V > >80 kW / 350.4 V = 228.3 amps > >228.3 amps / 2 parallel strings = 114 amps per string > > Note that I am talking purely about Modules, not the cells they are made > of. > So, the 228.3 Amp number is the only one that is relevant. > So the Leaf can PEAK at 228A or so, good to know. > Likely cruises at more like 15KW, so about 43A. > The 114 A value is relevant as a per string limit. You probably do not want to exceed that. If you do, you will be drawing more current from each module than the Leaf did. Leaf used parallel strings to get up to ~228 A per PACK. Leaf highway cruising takes 15-20 kW depending on specific condtions. This is for a Chevy S10. (converted some years ago using Lead-acid, we are > updating it) > I THINK we can fit 85 Modules in the battery boxes, which should > significantly improve range over the old Golf Cart batteries. > Don't forget to account for the degradation many Leaf batteries have experienced. You might prefer used Tesla modulea. > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20200802/e1d46ba6/attachment.html> _______________________________________________ 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)
