Recent content by Dougt

I don't think that is right. Adding another battery of equal capacity and voltage (in this case 48V 10ah SLA) in parallel doubles the Amp-hr capacity and current capability. There is no need to tie the individual cells together, as this is SLA chemistry and I doubt very much his bike has any...

I think you are confusing parallel with series. Putting them in parallel would mean the same voltage, but double the capacity and double the battery current capability (but current is likely limited by your controller). You need to check your controller, but it is likely about 50-60V max...

From your original post I gather your goals are primarily increased range, and secondly increased speed. Your idea of using a rheostat doesn't sound appropriate at all, even if you knew your controller could handle more volts. Also know that other systems on your moped are likely made for the...

Thanks, Rix. 18x6.4mm nipples seems too small for my wheel. The nipple holes in the rim are 8.1mm diameter. I'm guess your ERD is about right though. I plan to buy the spokes from Buchanan and the aluminum nipples from either Buchanan or Prowheel (prowheel cheaper and they are available...

I have no doubt that the cromotor is one of the best motors out there (that doesn't require extensive modification to use), but it is also one of the more expensive and there is a long wait to get one. I would like to compare it to others, and the only way to objectively do that is using...

Does anybody have a performance test report for the cromotor at 72V (or so) they could post here? I see there is one for 48V posted early in this thread, but not sure how well that scales...current should scale linearly, and input power as V^2, but that isn't exactly true, since the magnetic...

I disagree - I think it could possibly lead to problems. Not saying this is happening, but the shape of the hysteresis loop of steel undergoing flip-flops in magnetization polarity, such as the stator steel does in a operating motor, is very important in regard to energy losses. Any changes...

Folks, after doing some reading, I think I have found the answer. The phenomena is called "magnetic aging". from wikipedia article on electrical steels: "...The presence of carbon has a more detrimental effect than sulfur or oxygen. Carbon also causes magnetic aging when it slowly leaves...

I agree, so why would a vendor even bring it up? Usually people don't want to say their products will wear out in 3 years, especially if that isn't true. I am just wondering if we are missing something, or if the design or materials of the particular motors listed are problematic. It would...

I agree with most of what you posted. As for hard/soft, sorry I should have made it clear that by "soft" steel, I mean't magnetically soft - which means it doesn't retain much magnetization (low remanence) and the magnetic orientation is easily changed (low coercivity). An example of a...

I would add that a permanent magnet can be partially demagnetized by strong external fields. I don't have any idea if the fields from say putting 200a in the phase wires is enough, but I doubt it (although the demagnetization also gets easier with elevated temps). I agree though, a well...

Vito, I have questions about the 3-5 year lifetime. What steel are you talking about? Do you mean the permanent magnets? I don't want to hijack your for-sale posting with technical questions, so could you go to this thread and answer them...

In the for sale new section, a guy that is selling QS motors is claiming that they only last 3-5 years before the "steel" "loses its magnetization" and the steel needs to be replaced to bring back efficiency. Since QS builds a large percent of the motors that are re-branded and sold for...

I'm really getting confused now. Does anybody have a graph of the performance test curves of a cromotor? Looking at the the two QS motors I linked to in my post above, the v3 is only 5% better than the v2. But then I compared to another cromotor looking clone, the evel gt4000...

Hi Cromotor guys, In the "for sale section" there is a guy selling QS motors that he says are identical to the cromotor, in both form and performance. http://endless-sphere.com/forums/viewtopic.php?f=31&t=65929 Is this true? He posts two performance curves, on for V2 and one for V3...