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  1. M

    Thread for new battery breakthrough PR releases

    they should make 40 & 60 ah ones, it would cost way too much to get useable voltage levels with that 600 ah one.
  2. M

    1,000lb "Elec-tow’d” Electric Tow’d Dune Buggy Build Thread

    the whole problem with manufacturers trying to market a new car is that they have to meet the expectations of the federal government, as well as the public. So, the fed wants a car that is crash safe and has low emissions. got the emissions part, but that car is dead in a crash. the general...
  3. M

    Thread for new battery breakthrough PR releases

    Managed to get more detailed specifications for the 15ah cell: according to this its capable of 90 amps and 20,000 cycles which makes it much more worth the 60$, but not sure how many seconds its capable of doing those amps. cell 单体电芯 Model 规格型号 TK2012-2.4/15　 Capacity 容量 15Ah...
  4. M

    Thread for new battery breakthrough PR releases

    theres some here with a higher C rate: http://www.alibaba.com/product-gs/627190393/2_3V_11Ah_Lithium_Titanate_Battery.html *edit* got a responce for pricing apparently the model i just linked is stopped (cant imagine why its a much better model) they now sell the 2.4v 15ah cell capable of 3C...
  5. M

    a123 anr26650m1a

    I bought some of these cells, but they didnt come with tabs attached. Does anyone know where in florida i might be able to get tabs attached? I tried batteries plus and they dont do lithium ion only primary lithium chemistries.
  6. M

    gaia ltc

    http://www.gaia-akku.com/en.html so anyone manage to contact them or know a reseller? emailed, but so far no responce - hoping this isnt another company who only deals with manufacturers
  7. M

    Hipower cells

    Anyone here have hipower lithium iron phosphate cylindrical cells? If so, care to share your thoughts on them?
  8. M

    closed loop sinusoidal current control

    So, ive been looking for a controller that does this and im not really sure which ones do or not. The kelly controllers listed as recommended for the PMAC 0913 motenergy motor say they do a control loop but dont say if its closed loop or open loop. From an article ive read it seems as though you...
  9. M

    lithium iron phosphate shelf life

    ok so it sounds like the 2008 stock (3 years) has lost its theoretical 10ah and is stuck at 9.5/9.6 which would put it at 1.33% to 1.66% permanent capacity loss per year. But thats just theoretical, wish we had data on batteries actually tested 3 years ago and tested again today. I am asking...
  10. M

    lithium iron phosphate shelf life

    So does anyone here have some lithium iron phosphate cells that they tested the capacity of 2-3 years ago that could redo the tests now to see how much of their capacity was lost? Trying to find out the average capacity loss per year. Lithium cobalt for example loses capacity depending on...
  11. M

    Motor efficiency

    those links dont seem to explain why i need 180 amps to go into the controller in order to get 125 amps into the motor. Wouldnt this mean im using 44% more DC amps in order to get the AC amps, therefore reducing the efficiency? edit, also: in the link i found: V = E + IR = 8 + (4 x .5) = 10...
  12. M

    Motor efficiency

    Ok, found an interesting equation: Efficiency = {(torque*rpm)/9549} kw / {volts*amps/1000} kw Using this equation plugging in numbers from that chart i get some interesting results... For example: at the 80 pound inches mark (9.03 Nm) it looks to be about 3800 rpm 74 v 60 amps So...
  13. M

    Motor efficiency

    an electric hybrid lightweight vehicle; eg 1400# car. Is efficiency related to the rpm as well as the torque? I found a document for a brushless DC motor (not sure if its perm magnet or not) www.powertecmotors.com/aeffe3.doc this seems to indicate that the percent of efficiency is worst at low...
  14. M

    Heinzmann SL-EC 180 Type 22B Brushless motor

    these look neat; cant find any sellers or graphs for efficiency etc though; but a water cooled bldc oooo
  15. M

    Motor efficiency

    how would i run this motor at its highest efficiency? You say it starts at 0%, goes to max, and then back down to 0%? So how can you keep it out of the low efficiency best? If im reading the chart correctly, then it looks like 60-200 pound inches 4000 rpm 3200 rpm So for every 5.7 rpm lost i...
  16. M

    Motor efficiency

    Im a bit confused as to the efficiency curve; your theory says max power should be at 50% efficiency, but i guess i dont understand the graphs for certain motors then because according to the pmac-ds graphic http://www.electricmotorsport.com/store/pdf-downloads/PMAC-DS.pdf i found here, it looks...
  17. M

    Why pay big bucks for batteries?

    the controller for that motor is not 1255 its 400-500$ http://kellycontroller.com/kbl4830124v-48v300abldc-controllerwith-regen-p-257.html http://kellycontroller.com/kbl7230124-72v300abldc-controllerwith-regen-p-263.html with that kit your paying for a bunch of other stuff than the controller...
  18. M

    Batteries that last 20 years.

    Chart in this shows the effect of SoC on lifecycle among other things. http://ecee.colorado.edu/~ecen2060/materials/lecture_notes/HEV_batteries.pdf According to this one: http://www.fmadirect.com/support_docs/item_1229.pdf Pg 4 "In general, cycle life is about flat up to an operating...
  19. M

    Batteries that last 20 years.

    only lasts that if your very careful with the C rate and the charge/discharge percentages. Its very dependent on temperature.
  20. M

    Batteries that last 20 years.

    sweet; i hope it comes to market at a reasonable price it sounds even better than the SCiB batteries by toshiba which only get 6000 or so cycles and cost too much.
  21. M

    Thread for new battery breakthrough PR releases

    http://endless-sphere.com/forums/viewtopic.php?f=14&t=27750 theyre were tested, and found to be awesome. too bad they wont sell them to the general public
  22. M

    emerging battery technology

    anyone heard of the ultrabattery? http://www.alabc.org/research-areas http://www.axionpower.com/profiles/investor/fullpage.asp?f=1&BzID=1933&to=cp&Nav=0&LangID=1&s=0&ID=10298 or maybe lead acid/carbon http://www.fireflyenergy.com/index.php?option=com_content&task=view&id=204&Itemid=81 so many...
  23. M

    Doc GOT 100 samples of Titanate LTO cells update 6june 2011

    Does anyone know of any source for LTO cells? I know: altair nano wont sell SCiB wont sell ener1 wont sell Rumored pricing i have found: 2400$ for a 1.3 kwh altair nano module 675$ for a 100 wh SCiB module
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