Power in Flux
Likes Likes:  31
Page 3 of 14 FirstFirst 1234513 ... LastLast
Results 21 to 30 of 136

Thread: Spaceweasel's GSX-V

              
   
   
  1. #21
    Seņor Member podolefsky's Avatar
    Join Date
    Oct 2010
    Location
    Boulder, CO
    Posts
    3,890
    Post Thanks / Like
    Have fun - be safe (not too safe).
    - Noah Podolefsky -
    The GSX-E

  2. #22
    Senior Member Spaceweasel's Avatar
    Join Date
    Oct 2012
    Location
    Denver, CO
    Posts
    380
    Post Thanks / Like
    How convenient. Someone wrote a DIY sheet for my build: http://www.cracked.com/blog/the-21-i...y-diy-project/

  3. #23
    Senior Member Spaceweasel's Avatar
    Join Date
    Oct 2012
    Location
    Denver, CO
    Posts
    380
    Post Thanks / Like
    I've been slacking on the build, but have recently been toying around with the idea of upping my 72v build to 84v or 96v. Any thoughts on the advisability of over-volting a D&D ES 15-6 with an Alltrax 7245 450a controller at those voltages?

  4. #24
    Seņor Member podolefsky's Avatar
    Join Date
    Oct 2010
    Location
    Boulder, CO
    Posts
    3,890
    Post Thanks / Like
    The 7245 has a 90V limit. There isn't really a way to make it work at more than 72V (which is actually 76.8V nominal). If you go to 84V (28s = 89.6V nominal), then the pack will sit at around 93V even after sitting for a while off the charger (figure about 3.3-3.4V per cell at rest).

    You could go with 26s, which would keep you under 90V resting. Finding a charger would be the tough part.
    - Noah Podolefsky -
    The GSX-E

  5. #25
    Senior Member Spaceweasel's Avatar
    Join Date
    Oct 2012
    Location
    Denver, CO
    Posts
    380
    Post Thanks / Like
    So.... I'm looking for suggestions. I have had to scale back the build budget (4 year olds are expensive and don't appreciate my prioritizing batteries over legos). But I still want to get this thing up and running. The 60ah 72v GBS system at $3,300ish is out, as nice as it is.

    My priorities are 1) cost 2) power 3) range - in that order.

    Working my way up that ladder, I have a 15 mile round trip commute, so lets set 20 mile range as a minimum. I don't want to drop down to scooter levels of acceleration - if I hand the keys to someone to show off the potential of Electric, I want them to smile. I'd like to keep my costs down to $1-1,500 (but I still need a charger and sundry other bits).

    Lead? $400ish for 35ah.
    Headways? $700ish for a self built 24s1p 15ah pack - could I just keep saving and build new packs to parallel as $ becomes available?
    Hi-Power 10ah (24s2P)? $720 http://www.thunderstruck-ev.com/hi-p...-closeout.html - oops, almost sold out.
    GBS 20ah cells? $1000 with balancers http://www.electricmotorsport.com/st...f_gbs_20ah.php
    2 A123 36v 20ah packs wired in parallel? $1,100 w charger and BMS http://endless-sphere.com/forums/vie...6395&start=100
    GBS 40ah package? $2,500 with everything - suck it up and save up for it?
    Other options?

  6. #26
    Seņor Member podolefsky's Avatar
    Join Date
    Oct 2010
    Location
    Boulder, CO
    Posts
    3,890
    Post Thanks / Like
    You'll need at least 30Ah to assure yourself 20 mi of range. I get 40-50 with my 60Ah cells...if there's much riding over 45mph, it's more like 40mi.

    I'd always say save up for GBS 40Ah, but easier said than done.

    If you buy lead, you'll be buying it again in a year because it just doesn't last.
    - Noah Podolefsky -
    The GSX-E

  7. #27
    Senior Member Spaceweasel's Avatar
    Join Date
    Oct 2012
    Location
    Denver, CO
    Posts
    380
    Post Thanks / Like
    Please tell me why I'm an idiot...
    I found 4 slightly used Headway packs that are 24v 40ah 4p8s each. Could three of these be linked together to form a 72v 40ah pack? Or upgrade my Altrax controller to a Kelly and run all 4 for a 96v 40ah system? Will my bike explode in a giant ball of flame if I try?
    I seem to recall someone saying that it was a bad idea to string batteries together in a mixed series/parallel set up, but I don't know why this is.

  8. #28
    Seņor Member podolefsky's Avatar
    Join Date
    Oct 2010
    Location
    Boulder, CO
    Posts
    3,890
    Post Thanks / Like
    You can string parallel sets together in series just fine, so putting those packs in series to make 72V or 96V would be fine. It is less advisable to take series strings and then parallel them.

    http://elithion.com/wp_parallel_cells.php
    - Noah Podolefsky -
    The GSX-E

  9. #29
    Senior Member Spaceweasel's Avatar
    Join Date
    Oct 2012
    Location
    Denver, CO
    Posts
    380
    Post Thanks / Like
    So would that be annotated 4x4p8s? Groups of 4 cells arranged in parallel (to get 40ah), 8 of those groups in series to get 24v, 4 of those packs in series to get 96v?
    And, secondly, what are your thoughts on selling the Altrax and picking up a Kelly rated for 96v? With your experience with the components, what might the performance difference look like?
    The Kellys are rated up to 350amps (http://kellycontroller.com/kbl96351e...en-p-1258.html), while the Altrax is 450. I'd lose some amperage but gain 24volts. Plus the possibility of regen.

  10. #30
    Seņor Member podolefsky's Avatar
    Join Date
    Oct 2010
    Location
    Boulder, CO
    Posts
    3,890
    Post Thanks / Like
    If you're using the D&D series motor, just stick with Alltrax 7245. You won't get regen with the series motor. Also, that motor is made for 72V, 450A. You won't gain anything by going to higher voltage / lower amps if the total power is the same (which it is with the 72V / 450A and 96V / 350A, roughly).

    Usually cell configuration is written XsYp, meaning Y cells in parallel and then X of those in series. If you put 8 of those 4s4p packs in series, you would write 32s4p. If you wrote 4x4s4p, that would be putting four 4s4p packs in parallel - which is the same as 4s16p.

    Make sense?
    - Noah Podolefsky -
    The GSX-E

  11. Likes Duck-Stew liked this post
Page 3 of 14 FirstFirst 1234513 ... LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •