Search results

Date Relevance Most replies

  1. A

    supercap battery boosting

    example: 24v, 20ah, 3C <-----> 24v, 5ah, 100C -----> load batteries are series-connected direction of energy flow>>>>>>>>>>>>>>> As the load is presented to the batteries, current flows from the 100C battery to the load. As the 100C battery is depleted, current flows from the 3C battery to the...
  2. A

    supercap battery boosting

    Instead of expensive supercapacitors, use a relatively large, low C-rate battery to trickle charge a relatively small, high C-rate battery. Connect the high C-rate battery to the load.
  3. A

    CF or Glass Fiber over PVC Pipe

    Fiberglass laid up on a balsa wood dowel core may be a good strength to weight compromise.
  4. A

    Easiest to convert alternators?

    If it's not too late, before you purchase and install your N45 paperweight of doom, you may want to carefully listen to https://www.youtube.com/watch?v=vp44tW1VDGg starting at 5:00.
  5. A

    Safety Gear

    Things are not always what they appear to be: http://www.onestreet.org/images/stories/pdf/Efficacy_of_Bicycle_Helmets.pdf http://crag.asn.au/?p=67
  6. A

    Sodium Sulfate lead/acid extender

    Not necessarily. About 80% of "dead" lead acid batteries have heavily sulfated and/or dendrited plates. The preferred method of revival is to desulfate the battery with a high-quality desulfator. After the battery is desulfated, SLOWLY and totally discharge it with a small load, such as an...
  7. A

    Sodium Sulfate lead/acid extender

    Very interesting. Excellent explanation!
  8. A

    Sodium Sulfate lead/acid extender

    I know, I know, Luke. But there seems to be a lot of anecdotal evidence of lead acid batteries spontaneously reversing their polarity, especially after sitting unused for a while: http://www.modelboatmayhem.co.uk/forum/index.php?topic=6677.0...
  9. A

    Sodium Sulfate lead/acid extender

    He should reverse the connections. However, as an interesting aside, a lead acid battery will sometimes spontaneously flip polarity. If it does, you should clearly mark the new polarity on the terminals and reverse the connections to the battery terminals.
  10. A

    Sodium Sulfate lead/acid extender

    There are a few methods of increasing the life of lead acid batteries. Putting additives in the electrolyte is not one of them. A well-designed high-power desulfator will remove PbSO4 from the plates. The PbSO4 will be reconstituted in the electrolyte. Another method, used on Allied...
  11. A

    Changes to forum categories - comments/suggestions invited.

    Subcategories may facilitate navigation and search.
  12. A

    Things that break in the rain...

    http://boeshield.com/
  13. A

    Rolling Resistance Calculator

    Formulae attached, as requested.
  14. A

    Rolling Resistance Calculator

    Which spreadsheet and version are you using? Perhaps that has something to do with the problem that you're having.
  15. A

    Rolling Resistance Calculator

    I apologize if my reply sounded sarcastic. It wasn't meant to be that. The error trapping was meant to prevent more than one field to be populated in each of the three records. Has anyone else had the same problem as Fizzit?
  16. A

    Rolling Resistance Calculator

    ...all of which are virtually inconsequential in regard to rolling resistance. Inflation pressure is, by far, the most important factor.
  17. A

    Rolling Resistance Calculator

    Apparently you had an entry in another load input field at the same time.
  18. A

    Rolling Resistance Calculator

  19. A

    Light Rail Projects

    http://www.worldtransitresearch.info/research/3693/ http://cts.virginia.edu/docs/UVACTS-5-14-68.pdf http://skytrainforsurrey.org/2012/03/15/104th-ave-congestion-growth-higher-than-all-other-surrey-corridors-lrt-would-be-infeasible/
  20. A

    Light Rail Projects

    Light rail transit (LRT) generally increases traffic congestion. LRT vehicles are given priority at at-grade crossings and signalized intersections, thereby delaying street traffic.
  21. A

    Light Rail Projects

    In the past, I've been a project manager on well over $5 billion in light-rail transit projects. I'm sad to say that, to my knowledge, there has not ever been any public transit system that has broken even on fare box revenue, much less "paid off".
  22. A

    Oil cooling your hub- NOT snake oil!

    That would be my choice for cooling a hub motor. Mineral oil has been used for many years to cool transformers. It is a dielectric fluid and is readily available. Transformer manufacturers generally pull nitrogen and then pull vacuum to remove any water vapor prior to filling the tank with...
  23. A

    world's fastest ebike?

    Very good point. The down tube generally absorbs about 45% of the total energy stored in the frame. Roughy 60% of that is torsional and 40% out-of-plane. I would think that the semicircular geometry of the downtube would greatly compromise the inherent strength of a circular downtube.
  24. A

    Anyone know of good compact DC fuses?

    If you're only concerned about short-circuit protection and not overcurrent protection, you may consider cable limiters: http://www.cooperindustries.com/content/dam/public/bussmann/Electrical/Resources/Data%20Sheets/Bus_Ele_DS_1042_K_Series.pdf They only provide short-circuit protection and...
  25. A

    Lipo not so dangerous....

    Install the LiPo battery pack in a liquidtight container. Fill the annular void with a dielectric fluid. The fluid will serve a dual function. It will quench sparks or fire from the batteries. It will also serve to cool the batteries.
Back
Top