Search found 568 matches

by serious_sam
Apr 20 2021 3:56am
Forum: EBike Technical
Topic: Modifying a Hub Motor
Replies: 46
Views: 1109

Re: Modifying a Hub Motor

fatty wrote:
Apr 19 2021 8:24am
serious_sam wrote:
Apr 19 2021 8:16am
Power.
I never made any claims about power.
If you never admit when you've put your foot in your mouth (and you never do), you'll never get rid of that bad breath.

And your breath stinks bad.

I'm out.
by serious_sam
Apr 19 2021 8:16am
Forum: EBike Technical
Topic: Modifying a Hub Motor
Replies: 46
Views: 1109

Re: Modifying a Hub Motor

The OP didn't specify a controler. So you're cherry picking a case to try to prove your point. I just used a different controller spec to disprove your point. Here it is with your battery and motor combo, but a different controller. https://ebikes.ca/tools/simulator.html?motor=MX4506&batt=cust_...
by serious_sam
Apr 19 2021 7:53am
Forum: EBike Technical
Topic: Modifying a Hub Motor
Replies: 46
Views: 1109

Re: Modifying a Hub Motor

Ahem... Different motor winding, same everything else. 7kW vs 8.5kW peak power available, winding dependent. https://ebikes.ca/tools/simulator.html?motor=MX4504&batt=cust_84_.02_15&cont=cust_150_250_0.01_T&hp=0&cont_b=cust_150_250_0.01_T&motor_b=MX4503&batt_b=cust_84_.02_15&...
by serious_sam
Apr 19 2021 6:51am
Forum: EBike Technical
Topic: Modifying a Hub Motor
Replies: 46
Views: 1109

Re: Modifying a Hub Motor

To be clear, you are not rewinding the motor to be more "powerful" unless you achieve more copper density but you are changing the amount of voltage and current to suit your power supply This is nonsensical. Motor winding is independent of supply voltage and current. As explained above, r...
by serious_sam
Apr 14 2021 5:16am
Forum: EBike General Discussion
Topic: Best Phase Wire Connectors & MXUS 3kw stock wires
Replies: 10
Views: 220

Re: Best Phase Wire Connectors & MXUS 3kw stock wires

I changed my V3 3T motor wires out to 8AWG and regularly run 10kW. But you can't run that level of power sustained anyway. The motor just can't shed heat that fast. Short bursts with time to cool in between. So if you keep the original 12AWG motor wires as short as physically possible, they'd probab...
by serious_sam
Apr 06 2021 8:09pm
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 505
Views: 86252

Re: Spot Welding Copper Strips to 18650 Battery Cells

Better to have a rigid battery pack with compliant mounting to the board. A flexible battery pack is a terrible idea. IMO.
by serious_sam
Mar 23 2021 6:37am
Forum: EBike Technical
Topic: Modifying a Hub Motor
Replies: 46
Views: 1109

Re: Modifying a Hub Motor

Does anyone have any resources on how to rewind a motor for increased current draw? The controller is the thing that dictates current flow, not the motor. You can rewind the motor to produce more torque per amp (Kt=Nm/Amp), at the cost of a lower speed per volt (Kv=rpm/Volt). https://endless-sphere...
by serious_sam
Mar 20 2021 4:17am
Forum: Battery Technology
Topic: Why isn't "node charging" through the balance leads more common?
Replies: 44
Views: 1275

Re: Why isn't "node charging" through the balance leads more common?

The problem is that you don't need much deltaV to get 8A. Say your group has an IR of 10mOhms. 0.01x8=0.08V True. But I absolutely guarantee your balance wires + connector do not have a resistance of less than 10mOhms. That limits current as well. Which is fine - because the primary charge current ...
by serious_sam
Mar 17 2021 3:53pm
Forum: Battery Technology
Topic: Why isn't "node charging" through the balance leads more common?
Replies: 44
Views: 1275

Re: Why isn't "node charging" through the balance leads more common?

*If the pack is balanced... Even if it isn't balanced. It's very rare, for example, for one cell to take full charge current and the neighboring one to take zero. That's the only case in which you'd see full charge current through a balance lead. More often cells are somewhat out of balance, and th...
by serious_sam
Mar 16 2021 4:37pm
Forum: Battery Technology
Topic: Why isn't "node charging" through the balance leads more common?
Replies: 44
Views: 1275

Re: Why isn't "node charging" through the balance leads more common?

JackFlorey wrote:
Mar 16 2021 4:35pm
fatty wrote:
Mar 16 2021 12:01am
Are you referring to node charging each individual cell through the balance leads? Or traditional bulk charging with trickle balance through the balance leads?
Specifically I am saying that from the battery's perspective - those two are identical.
*If the pack is balanced...
by serious_sam
Mar 14 2021 6:38pm
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 505
Views: 86252

Re: Spot Welding Copper Strips to 18650 Battery Cells

I just tried the above, nickel plated steel with the 01.mm copper, and it works pretty well. You think that 0.1mm copper is enough for 30A ? I was looking at the ampacity chart i had found on a thread in this forum from Matador and it says that a 10mm by 0.1mm copper is good for 15 amps only. I jus...
by serious_sam
Mar 13 2021 10:13pm
Forum: EBike Technical
Topic: Nucular Electronics owner's thread (setup infos, FW updates, links etc.)
Replies: 485
Views: 47993

Re: Nucular Electronics owner's thread (setup infos, FW updates, links etc.)

HTTR wrote:
Mar 13 2021 2:05pm
What makes the Nucular controllers so good. Hadrware ? Software ?
Yes.
by serious_sam
Mar 13 2021 10:11pm
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 505
Views: 86252

Re: Spot Welding Copper Strips to 18650 Battery Cells

I have some 0.1 copper sheet. I just tried an infinite slit with it and it welds much better than the 0.2mm copper. The problem is that the battery is putting out 60 amps continuous and so the 0.1mm copper is not enough as far as i know. I could order some 0.15mm and try with that but I would need ...
by serious_sam
Mar 12 2021 10:41pm
Forum: Battery Technology
Topic: Amazon load testers, Magic Smoke
Replies: 11
Views: 332

Re: Amazon load testers, Magic Smoke

FWIW, that'[s WAAAAAAAYYYYY too much thermal paste, and will help insulate the heat from passing out of the FET. It makes no practical difference (to thermal performance) how much thermal paste you use, as long as: 1. It is actually thermal paste. 2. There is enough to cover the surface of the comp...
by serious_sam
Mar 06 2021 3:50am
Forum: Motor Technology
Topic: What controller for 72v, 100+ amps?
Replies: 12
Views: 686

Re: What controller for 72v, 100+ amps?

Ah - good to know. I was told the battery will produce 350 phase amps, so believed I needed to base it on that! I would not put 350Ap through a MXUS3k. Depending on the wind, that could be more torque than the axle (or frame) could handle. The 4T is approx 1Nm/A. The 5T is higher. Maybe the 3T woul...
by serious_sam
Mar 06 2021 3:15am
Forum: Motor Technology
Topic: What controller for 72v, 100+ amps?
Replies: 12
Views: 686

Re: What controller for 72v, 100+ amps?

PRW wrote:
Mar 04 2021 1:20pm
I ended up booking a Nucular 24F - wait is supposedly 5 months.
Nucular is well worth the wait.

FWIW, 12F would be fine for your setup. 84V (20S). 150Ab. 250Ap. MXUS3k.
by serious_sam
Mar 05 2021 4:51am
Forum: Battery Technology
Topic: 'on board' 1.5kW charger. Which alibaba supplier?
Replies: 170
Views: 4195

Re: 'on board' 1.5kW charger. Which alibaba supplier?

CC stage AKA Bulk, is before the batt hits the max-V setpoint. the battery does not decide the voltage, the charger does. No, it is negotiated, at start of Bulk depends in chemistry resistance SoC and current rate. I mean, it's crystal clear by this statement that john has absolutely zero understan...
by serious_sam
Mar 04 2021 4:25pm
Forum: Battery Technology
Topic: 'on board' 1.5kW charger. Which alibaba supplier?
Replies: 170
Views: 4195

Re: 'on board' 1.5kW charger. Which alibaba supplier?

the sooner you stop after the CC-to-CV transition point the better. You keep talking about this transition like it means something to the cell. It does not. You do know that it is a completely arbitrary thing right ? Totally dependent on the cell IR and charge current. Absolutely nothing to do with...
by serious_sam
Mar 03 2021 11:23pm
Forum: Battery Technology
Topic: 'on board' 1.5kW charger. Which alibaba supplier?
Replies: 170
Views: 4195

Re: 'on board' 1.5kW charger. Which alibaba supplier?

Really, it's fcking stupid to argue about this. The bottom line is if it can be used to put charge into your cells, then it is a charger , as far as the cell is concerned. Might not be "good". Might not be "smart". Might not even be "safe". But if it can be used to char...
by serious_sam
Mar 03 2021 4:18am
Forum: Battery Technology
Topic: CarettaBMS, Open Source BMS
Replies: 4
Views: 185

Re: CarettaBMS, Open Source BMS

Hrastovc wrote:
Mar 03 2021 3:25am
Digital outputs, WiFi, Bluetooth are available on the master module,
Awesome.
Hrastovc wrote:
Mar 03 2021 3:25am
only when powered from the external source.
Isolated SMPS to run off full pack voltage ?
by serious_sam
Mar 02 2021 7:05pm
Forum: Battery Technology
Topic: CarettaBMS, Open Source BMS
Replies: 4
Views: 185

Re: CarettaBMS, Open Source BMS

I am looking for some feedback and any feature requests. Sounds really good. What is the sleep/monitor state current draw for each module ? Are those isolators and master module powered from the end cell/group(s) only, or from full pack voltage (all cells drained equally) ? Powering the system from...
by serious_sam
Mar 02 2021 5:06am
Forum: Battery Technology
Topic: Why isn't "node charging" through the balance leads more common?
Replies: 44
Views: 1275

Re: Why isn't "node charging" through the balance leads more common?

every second or third thread in this subforum is for a misbehaving (or incorrectly-spec'd) charger or failed BMS. Please stop exaggerating and perpetuating the BMS myth. There's no particular reason that BMSs should be any less reliable than any other electronic hardware. Think about it logically. ...
by serious_sam
Mar 01 2021 7:11pm
Forum: EBike General Discussion
Topic: Build pack onto and around frame tube, rather than inside?
Replies: 27
Views: 541

Re: Build pack onto and around frame tube, rather than inside?

How many cells would you get in a string, along the short length of the downtube? You'd be limited to something like 10S.
by serious_sam
Mar 01 2021 7:03pm
Forum: Battery Technology
Topic: Why isn't "node charging" through the balance leads more common?
Replies: 44
Views: 1275

Re: Why isn't "node charging" through the balance leads more common?

I would say just from a reliability standpoint, a single bulk charger plus BMS is an order of magnitude more reliable than an individual charger per cell group (I.e. node charging). A charger is a relatively complex circuit with many points of failure, whereas a BMS usually has relatively few compon...
by serious_sam
Feb 27 2021 6:05pm
Forum: EBike General Discussion
Topic: Build pack onto and around frame tube, rather than inside?
Replies: 27
Views: 541

Re: Build pack onto and around frame tube, rather than inside?

fatty wrote:
Feb 27 2021 5:43pm
-No cell holders or pack structural members necessary -- strong and light.
If you don't have cell holders, what is the structure ? I.e. how are the cells held to the frame ? Would this method work for non-cylindrical tube frames ?