Search found 6055 matches

by john61ct
Apr 20 2021 12:53am
Forum: Motor Technology
Topic: Oil cooling a motor with transformer oil/dielectric fluid - the next frontier?
Replies: 39
Views: 1320

Re: Oil cooling a motor with transformer oil/dielectric fluid - the next frontier?


TDB wrote:Do you have shares in Opticool? :)
He's not claiming it would work, just cheerleading for people to try testing it

by john61ct
Apr 19 2021 11:38pm
Forum: Items Wanted
Topic: Prodecotech 48 Volt (51.2V Nominal) 12 Ah LiFeP04 battery - Good or bad Want to buy one
Replies: 26
Views: 2707

Re: Prodecotech 48 Volt (51.2V Nominal) 12 Ah LiFeP04 battery - Good or bad Want to buy one

tblakeng wrote:Does it need to be that brand? Why not just any 48v lion plug it right in
And although LFP at 3.2V nominal, is in the LI family of chemistries, li-ion usually means those specifically rated 3.6-3.7V
by john61ct
Apr 19 2021 11:04pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1330
Views: 204102

Re: kWeld - "Next level" DIY battery spot welder

Just LFP's lower voltage brings 6S down quite a bit.

4S will be 12-13.3V
by john61ct
Apr 19 2021 11:00pm
Forum: EBike Technical
Topic: Ampy: Open source python display/interface project for ASI controllers
Replies: 21
Views: 1604

Re: Ampy: Open source python display/interface project for ASI controllers

On behalf of the community and my future self,

Thank You!
by john61ct
Apr 19 2021 4:12am
Forum: EBike General Discussion
Topic: Any way to verify AH on a battery?
Replies: 12
Views: 342

Re: Any way to verify AH on a battery?

Yes I meant finished packs, normal IRL usage

charged to 4.05-4.10Vpc

LVC set at 3.4-3.6V not 2.8Vpc

discharged at maybe hundreds of amps peak, not CC at the 10-20 hour rate

by john61ct
Apr 19 2021 4:07am
Forum: EBike Technical
Topic: Ampy: Open source python display/interface project for ASI controllers
Replies: 21
Views: 1604

Re: Ampy: Open source python display/interface project for ASI controllers

Very sensible approach not trusting cheap BMS for high currents. I do not even use them for charge control nor balancing, RC Hobby chargers are faster and more reliable. As a failsafe backup HVC maybe. Dual port means one for charge control HVC, separate path for discharge LVC, while single port one...
by john61ct
Apr 18 2021 9:31pm
Forum: Battery Technology
Topic: "desulfate" 40T and 30Q and VTC6 and P42a
Replies: 59
Views: 2076

Re: "desulfate" 40T and 30Q and VTC6 and P42a

if i need to leave a battery charging for days to try and top balance it, thats plain moronic in my opinion and probably kills weak battery packs faster than anything else actually i should say, top balancing older packs to 4.2v is plain moronic and only balance at one point, top, bottom or your lv...
by john61ct
Apr 18 2021 9:09pm
Forum: Motor Technology
Topic: Oil cooling a motor with transformer oil/dielectric fluid - the next frontier?
Replies: 39
Views: 1320

Re: Oil cooling a motor with transformer oil/dielectric fluid - the next frontier?

Other relevant http://www.cnqsmotor.com/en/article_read/Statorade%20Ferrofluid/680.html http://www.cnqsmotor.com/en/article_read_668.html http://www.cnqsmotor.com/en/article_read/HubSink%20Set/681.html http://www.cnqsmotor.com/en/article_read_853.html http://www.cnqsmotor.com/en/article_read_381.htm...
by john61ct
Apr 18 2021 8:53pm
Forum: EBike Technical
Topic: Ampy: Open source python display/interface project for ASI controllers
Replies: 21
Views: 1604

Re: Ampy: Open source python display/interface project for ASI controllers

Wow fantastic! Yes the lower range stop-charge setpoint 3.42V to 3.48V is for "normal daily-use" cycling in production, depends on charging C-rate and cell temperatures. Periodic "maintenance cycling" balancing / cap testing etc will use cell mfg datasheet values, maybe annually ...
by john61ct
Apr 18 2021 7:40pm
Forum: Motor Technology
Topic: Oil cooling a motor with transformer oil/dielectric fluid - the next frontier?
Replies: 39
Views: 1320

Re: Oil cooling a motor with transformer oil/dielectric fluid - the next frontier?


markz wrote:I believe there is a solid reason
Yes statorade is his thing. I just meant as to his not investing time into experimenting with other options.

by john61ct
Apr 18 2021 7:17pm
Forum: Battery Technology
Topic: "desulfate" 40T and 30Q and VTC6 and P42a
Replies: 59
Views: 2076

Re: "desulfate" 40T and 30Q and VTC6 and P42a

that's a stretch higher pricing does not imply better quality usually just higher demand or tighter supply 99.9% of prospects still see 30Q as a good battery. If the maker thought the problem worth fixing they likely would have done so a ling time ago A more profitable and IMO likely strategy would ...
by john61ct
Apr 18 2021 4:56pm
Forum: EBike General Discussion
Topic: Any way to verify AH on a battery?
Replies: 12
Views: 342

Re: Any way to verify AH on a battery?

Even with the best quality cells and a purely honest vendor

a bank accurately rated at say 40Ah

would only deliver say 30-35Ah in real-life conditions aimed at good lifecycle longevity.
by john61ct
Apr 18 2021 4:54pm
Forum: EBike Build Threads
Topic: leaning trike cargo bike front end kit
Replies: 177
Views: 32337

Re: leaning trike cargo bike front end kit

OK, I can see that multiple wheels allows for better stopping power. So given a cargo bike, heavy-load out in front rather than to the rear is that the use case? Does the tilting increase the **speed** at which you can safely operate? I can't imagine actually tilting that much of an angle at the 15-...
by john61ct
Apr 18 2021 3:31pm
Forum: Motor Technology
Topic: Oil cooling a motor with transformer oil/dielectric fluid - the next frontier?
Replies: 39
Views: 1320

Re: Oil cooling a motor with transformer oil/dielectric fluid - the next frontier?

Pushing for heat shedding modifications to get more power out of a lighter smaller motor may not fit Grin's business model Those customers concerned with utility, focus on transportation, getting a load from A to B, maybe daily commuting are radically different than those out for fun, sporty use cas...
by john61ct
Apr 18 2021 5:14am
Forum: EBike Build Threads
Topic: leaning trike cargo bike front end kit
Replies: 177
Views: 32337

Re: leaning trike cargo bike front end kit

I have read the whole thread, and still don't understand the purpose.

Also, why is the EU different from the US?
by john61ct
Apr 17 2021 10:41pm
Forum: EBike General Discussion
Topic: Any way to verify AH on a battery?
Replies: 12
Views: 342

Re: Any way to verify AH on a battery?

Yes, if you have or get a load device that pulls a constant very low C-rate, traditionally over 20hrs If strictly constant amps then just use a timer otherwise put a coulomb counting wattmeter in between, a bit less accurate Draw down from 100% Full to 0% empty as defined by the battery data sheet. ...
by john61ct
Apr 17 2021 12:21pm
Forum: Battery Technology
Topic: Multi-BMS Setup! Will it work?
Replies: 9
Views: 249

Re: Multi-BMS Setup! Will it work?

A pack-voltage LVC can work but should be adjustable both based on the C-rate (higher amps means lower voltage) and on how well-matched or relatively healthy the cells are. Best used with bottom balancing, and intimate familiarity so intuition kicks in. Otherwise really best for the LVC to be based ...
by john61ct
Apr 15 2021 8:32pm
Forum: Items for Sale - New
Topic: QSMOTOR,0.5-12kW Electric Hub Motor & Mid Drive Motor Manufacture China
Replies: 1418
Views: 307115

Re: QSMOTOR,0.5-12kW Electric Hub Motor & Mid Drive Motor Manufacture China

LFP is much lower density.

A123 makes NMC pouches should deliver same level of energy and power in a lighter smaller form factor.

But much shorter lifespan and much more thermally risky.
by john61ct
Apr 15 2021 7:47pm
Forum: EBike Technical
Topic: Ampy: Open source python display/interface project for ASI controllers
Replies: 21
Views: 1604

Re: Ampy: Open source python display/interface project for ASI controllers

Works with LFP voltage values?

Still 21S max?

24s LFP for many is 87V, but for me more like 82V maximum
by john61ct
Apr 15 2021 9:01am
Forum: Battery Technology
Topic: Super fast charge
Replies: 18
Views: 475

Re: Super fast charge

Actually, one way to do this correctly would be to charge through the motor using a suitable controller. Adaptto and Nucular can do this: " Charge mode through the motor with the controller, plug any DC supply to the controller to charge your battery " Yes if you can figure it out, that's...
by john61ct
Apr 15 2021 9:00am
Forum: Battery Technology
Topic: Super fast charge
Replies: 18
Views: 475

Re: Super fast charge

I'd expect current limits are deliberately ignored with any charging method. I'm an advocate of safety, but due to the dynamics of equalization (and because it would be supervised) I actually don't see this as being that dangerous. Depends on resistance of the source side chemistry. From Lead to LI...
by john61ct
Apr 15 2021 7:39am
Forum: EBike Technical
Topic: Programming APT AE96600 controller (update: NOT recommended, unstable program)
Replies: 218
Views: 29993

Re: Programming APT AE96600 controller (update: NOT recommended , unstable program)


bingbwy wrote:Motor QS 5000w 12 inch
What model motor?

Wattage does not designate that. QS138, QS205?

by john61ct
Apr 14 2021 3:41pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1330
Views: 204102

Re: kWeld - "Next level" DIY battery spot welder

Yes better to rig a current-limiting circuit that does not vary so much as voltage / SoC drops. Of course a PSU / charger powerful enough to "just barely almost" keep up with the welder's Ah/minute consumption would allow for a smaller battery, just using it as a short-term buffer, maintai...