Search found 1397 matches

by Hummina Shadeeba
Apr 08 2019 5:11pm
Forum: General Discussion
Topic: Discharge unbalanced battery
Replies: 8
Views: 343

Re: Discharge unbalanced battery

I’d like to discharge at maybe 10 amps from the single 4v packs to balance. https://www.ebay.com/itm/New-6x-5-Ohms-50W-Aluminum-Housed-Wirewound-Power-Resistor-5ohm/141006406040?epid=1307735573&hash=item20d4a30198:g:9CsAAOxyi3FRzaAv .5 ohm resistor w 4v battery should get about 8 amps current draw a...
by Hummina Shadeeba
Apr 01 2019 10:16pm
Forum: Motor Technology
Topic: Why never see metal cast around wound stators?
Replies: 61
Views: 1733

Re: Why never see metal cast around wound stators?

It is better to get thinner laminations! Also, if you can find some (more like make some) square or triangle magnet wire, get way more copper fill and copper cross sectional area. Always good! Then its all about heat management, so perhaps more metal, which adds more weight to soak up the heat to t...
by Hummina Shadeeba
Apr 01 2019 1:10pm
Forum: Motor Technology
Topic: Bending magnetic flux
Replies: 0
Views: 91

Bending magnetic flux

I don’t see much info on the transverse flux design here or anywhere and hoping someone can link me. Tell me am I wrong in thinking the magnetic field of a “tooth” could be in a direction different from where bare coils would produce the field and maybe limitless: so you can redirect or bend the fie...
by Hummina Shadeeba
Apr 01 2019 12:15pm
Forum: Motor Technology
Topic: Why never see metal cast around wound stators?
Replies: 61
Views: 1733

Re: Why never see metal cast around wound stators?

It is better to get thinner laminations! Also, if you can find some (more like make some) square or triangle magnet wire, get way more copper fill and copper cross sectional area. Always good! Then its all about heat management, so perhaps more metal, which adds more weight to soak up the heat to t...
by Hummina Shadeeba
Apr 01 2019 12:11pm
Forum: Motor Technology
Topic: Why never see metal cast around wound stators?
Replies: 61
Views: 1733

Re: Why never see metal cast around wound stators?

Soon as the room temp super conductor becomes a reality at a price that's cheaper than a neo magnet then we will see some serious shit. Think of the current handling capability of such a beast but does it still have a decent bemf I would have though no so even at high speed the torque load could ri...
by Hummina Shadeeba
Mar 31 2019 1:37pm
Forum: Motor Technology
Topic: Why never see metal cast around wound stators?
Replies: 61
Views: 1733

Re: Why never see metal cast around wound stators?

But I haven’t gotten the indium yet as I’m beyond broke. Definitely plan to do it since I haven’t found any info of anyone doing similar and fear of increased eddy currents seems not a big deal. In my mind the controllers market has advanced a lot. Over the last maybe 5 years the Vesc was developed ...
by Hummina Shadeeba
Mar 21 2019 12:13am
Forum: E-Vehicles General Discussion
Topic: Motor kv and efficiency
Replies: 5
Views: 289

Re: Motor kv and efficiency

With the 100 pieces of copper in parallel being each fed with a 10 amp supply then the total current before split into the parallel strands would be 10,000 amps to get the same torque as the single 100 turns of the single wire doing 10 amps. The motor constant km. Same ohmic loss to torque. I guess ...
by Hummina Shadeeba
Mar 20 2019 1:33pm
Forum: E-Vehicles General Discussion
Topic: Motor kv and efficiency
Replies: 5
Views: 289

Motor kv and efficiency

It makes senses that a lower kv would be more efficient as it will have less switching in the esc maybe but would it be any less efficient in the motor? It seems the grim simulator incorporates the whole system and not possible to isolate the motor. while it’s said a motor will have the same km rega...
by Hummina Shadeeba
Mar 20 2019 1:17pm
Forum: E-Bike Technical
Topic: MeanWell Mods - S-150-24
Replies: 51
Views: 17211

Re: MeanWell Mods - S-150-24

I’ve got many meanwell copies I got off amazon or alibaba that are broken and wondering if someone around the bay are would want them or help me fix some. Is it possible to alter some of these similar power sources for a lower current output as I imagine they would be able to survive longer. Ive got...
by Hummina Shadeeba
Mar 18 2019 8:44pm
Forum: General Discussion
Topic: using voltage sag as indication of bad battery
Replies: 11
Views: 314

Re: using voltage sag as indication of bad battery

Mark I guess with that method you would be comparing the voltage by eyesight of the different p groups. that would work and be pretty simple but I figured a computer that knew what sag to expect and incorporated the temperature effects and the cycles of the battery would be better than me looking at...
by Hummina Shadeeba
Mar 18 2019 3:52pm
Forum: General Discussion
Topic: using voltage sag as indication of bad battery
Replies: 11
Views: 314

Re: using voltage sag as indication of bad battery

the bms and even the vesc will typically shut down when the whole pack gets to a certain low voltage but it doesn't take into account the amp discharge that's being done to hit that low voltage cutoff so I could go up a mountain with a crappy battery and have huge sag and the vehicle will shut down,...
by Hummina Shadeeba
Mar 18 2019 3:30pm
Forum: General Discussion
Topic: using voltage sag as indication of bad battery
Replies: 11
Views: 314

Re: using voltage sag as indication of bad battery

it seems a simple program (to someone who doesn't know how to program). If it were to work it would save space, time, money possibly replacing a bms if it were good enough, no? No. The primary reason you need a BMS on a li-ion battery is to monitor for cell imbalance, not for remaining life. it wou...
by Hummina Shadeeba
Mar 18 2019 12:34pm
Forum: General Discussion
Topic: using voltage sag as indication of bad battery
Replies: 11
Views: 314

Re: using voltage sag as indication of bad battery

it seems a simple program (to someone who doesn't know how to program). If it were to work it would save space, time, money possibly replacing a bms if it were good enough, no? surprised no one has tried making it or probably someone has. what happens with current and voltage in the WHOLE battery wh...
by Hummina Shadeeba
Mar 18 2019 12:18am
Forum: General Discussion
Topic: using voltage sag as indication of bad battery
Replies: 11
Views: 314

using voltage sag as indication of bad battery

can cells be relied on to perform consistently enough that a software program could pick up on an increased voltage drop under a given current draw from a complete battery and indicate a problem? It would first have to get to know how the battery behaved then if a cell or cells were damaged or disco...
by Hummina Shadeeba
Mar 16 2019 8:05pm
Forum: General Discussion
Topic: Discharge unbalanced battery
Replies: 8
Views: 343

Re: Discharge unbalanced battery

Say toaster is 1000w. 1000w / 115vac = 8.69 amps 115v / 8.69a = 13.23ohms 4.2v / 13.23 ohms = 0.313a So discahrge will be pretty slow for a big back, but fairly quick for a single small cell. parallel more loads for faster discharge. would you use the full 115 in the equation or would it be the roo...
by Hummina Shadeeba
Mar 14 2019 10:26am
Forum: General Discussion
Topic: Discharge unbalanced battery
Replies: 8
Views: 343

Re: Discharge unbalanced battery

Aha. There’s the math. Thank you.
by Hummina Shadeeba
Mar 13 2019 8:50pm
Forum: General Discussion
Topic: Discharge unbalanced battery
Replies: 8
Views: 343

Re: Discharge unbalanced battery

I hooked the overcharged pack up to my toaster! Nothing happened that I noticed and don’t think they were discharging, maybe they were. 4v. And then I tried to hook it up to a couple different bulbs and nilch. Is the voltage too low? I’m surprised. Maybe need a much higher wattage bulb? Thanks Luke....
by Hummina Shadeeba
Mar 13 2019 7:24pm
Forum: General Discussion
Topic: Discharge unbalanced battery
Replies: 8
Views: 343

Discharge unbalanced battery

I’m forgetting. Can I hook an incandescent bulb (or something that will discharge faster than leds) directly to my p groups to balance them? I’m
Remembering a toaster. Can I directly hook the toaster up to the 4.2v pack to get it down to 3.9?
by Hummina Shadeeba
Mar 06 2019 2:38pm
Forum: Motor Technology
Topic: Why never see metal cast around wound stators?
Replies: 61
Views: 1733

Re: Why never see metal cast around wound stators?

Galvanic corrosion would be possible between the indium and the nickel plated steel of the motor case but the copper wouldn’t be in contact as it would of course be insulated. Supposedly nickel will cover with oxides which should be removed for best thermal transfer but that seems nitpicking. Indium...
by Hummina Shadeeba
Mar 04 2019 1:38pm
Forum: Motor Technology
Topic: Why never see metal cast around wound stators?
Replies: 61
Views: 1733

Re: Why never see metal cast around wound stators?

But what short? There’s no short I’m finding indium easily gotten on Amazon and not tooo expensive but strangely all the indium stores I’ve called haven’t heard of using it in this way and seems Ill have to do it myself to find out zamac3 I see. There’s a bunch of options it seems with indium maybe ...
by Hummina Shadeeba
Mar 03 2019 9:19pm
Forum: Motor Technology
Topic: Why never see metal cast around wound stators?
Replies: 61
Views: 1733

Re: Why never see metal cast around wound stators?

The tin alloys would be cheap and maybe straight tin would work with a melt temp of 400f, soft, thermal expansion less then indium at least, great thermal transfer. 400f is no problem for the amount of time the coils would be at that temp with the cast metal around it and can use standard 200c wire....
by Hummina Shadeeba
Feb 27 2019 1:02pm
Forum: Stand-up E-scooters and E-skateboards
Topic: AT-One electric inline skates (quick update Feb 2019)
Replies: 211
Views: 32937

Re: AT-One electric inline skates (quick update Feb 2019)

Id like having a tiny battery so less weight. I see panels for sale today are able to capture about 22% of the sun energy and the best panels designed capture about 44%.
by Hummina Shadeeba
Feb 27 2019 12:50pm
Forum: Motor Technology
Topic: Why never see metal cast around wound stators?
Replies: 61
Views: 1733

Re: Why never see metal cast around wound stators?

No spinning stator so no added spinning mass.
by Hummina Shadeeba
Feb 26 2019 9:15pm
Forum: Motor Technology
Topic: Why never see metal cast around wound stators?
Replies: 61
Views: 1733

Re: Why never see metal cast around wound stators?

Those resins if any good are expensive. I think the best thing u could do, and it would be easily stripable if it fails, as apposed to resin, is solder. Or some other metal. https://www.google.com/amp/s/www.electronics-cooling.com/2006/08/thermal-conductivity-of-solders/amp/ https://www.engineeringt...