Search found 6185 matches

by john61ct
Jul 20 2021 8:59am
Forum: Motor Technology
Topic: QS203 3T Sabvoton 72100 need more low speed power?
Replies: 6
Views: 188

Re: QS203 3T Sabvoton 72100 need more low speed power?

never heard of twitchy being desirable

Do you mean delivering more torque at lower rpm?
by john61ct
Jul 19 2021 1:33pm
Forum: EBike Technical
Topic: Noob Question re BMS
Replies: 60
Views: 952

Re: Noob Question re BMS

A BMS is just a collection of functionalities to protect a battery and differ widely between various instances and price ranges. LVC is to stop discharging before voltage gets so low as to cause damage HVC is to stop voltage going too high while charging Either or both can be based off the lowest/hi...
by john61ct
Jul 17 2021 7:13pm
Forum: Items for Sale - New
Topic: TIG torch for battery spot welding
Replies: 32
Views: 764

Re: TIG torch for battery spot welding

Wow seems like a solid way to go for solid copper handling high amps! What would be a good petrol powered unit to get that 150A max off-grid? Also looking to do structural aluminum welding and ideally also handle high-current charging of large storage banks, worst case feed mains-style AC to AC-DC c...
by john61ct
Jul 17 2021 2:44pm
Forum: EBike General Discussion
Topic: Are fans needed to cool down battery packs?
Replies: 9
Views: 272

Re: Are fans needed to cool down battery packs?

High temperatures from outside Ambient may reduce longevity, but they do not do "damage".

Using the pack at a C-rate that causes heat rise internally is 1000x worse
by john61ct
Jul 17 2021 2:39pm
Forum: EBike General Discussion
Topic: float charging lifepo4
Replies: 19
Views: 294

Re: float charging lifepo4

I think overall, ridiculous.

But to be constructive, expand one LFP pack at the one desired system voltage.

Nothing but downside using voltage converters or keeping packs separate.
by john61ct
Jul 17 2021 2:08pm
Forum: E-Vehicles General Discussion
Topic: full charge voltage for a123.
Replies: 1
Views: 121

Re: full charge voltage for a123.

Have you been triple posting?
by john61ct
Jul 17 2021 2:01pm
Forum: EBike Technical
Topic: Programming ASI Bac 8000
Replies: 52
Views: 8071

Re: Programming ASI Bac 8000

Tony01 wrote: no support really
Hence my suggestion to check out Martin.

Sevcon is the same, worse.

Nucular has a 1-year wait it seems and only one model.

So what do you reco for high-amp FOC with variable regen?

by john61ct
Jul 17 2021 1:59pm
Forum: EScooters/EMotorcycles
Topic: My new electric motorcycle
Replies: 29
Views: 1369

Re: My new electric motorcycle

Albie72 wrote:Yes 1300 hundred USA dollars
means $130,000
by john61ct
Jul 17 2021 1:38pm
Forum: EBike General Discussion
Topic: full charge voltage for a123.
Replies: 3
Views: 109

Re: full charge voltage for a123.

Are you talking a 12S LFP pack? Anything above 41V will get you to Full. Getting closer to 43V will not accomplish anything, and reduce cell longevity. Your BMS may require a certain minimum to start balancig, IMO if higher than say 41.5V for mor than an extra half hour once a week, that means do no...
by john61ct
Jul 17 2021 1:32pm
Forum: EBike General Discussion
Topic: float charging lifepo4
Replies: 19
Views: 294

Re: float charging lifepo4

>a 3.3V charge input, at an Amps level slightly higher than your average Load consumption will work just fine. Note, if the amps output of the genset is even slightly below the average discharge rate you will inevitably run down your SoC to hit your LVC. So factor in a heavier load, higher headwind ...
by john61ct
Jul 17 2021 1:28pm
Forum: EBike General Discussion
Topic: float charging lifepo4
Replies: 19
Views: 294

Re: float charging lifepo4

I agree the big picture is foolish, but setting that aside, thought experiment assuming everything is reliable. 3.32V to 3.35Vpc is your 100% Full target for sitting isolated at rest 3.0V is your 0% for minimum security 3.1V for decent longevity, same conditions. So, a 3.3V charge input, at an Amps ...
by john61ct
Jul 17 2021 1:03pm
Forum: Motor Technology
Topic: Grin Motor Simulator and the back of my fag packet don't agree
Replies: 6
Views: 211

Re: Grin Motor Simulator and the back of my fag packet don't agree

For those who don't know

a packet of fags means cigarettes, "seat of the pants" calculations
by john61ct
Jul 16 2021 3:12pm
Forum: EBike General Discussion
Topic: Challenges of Securing Products
Replies: 5
Views: 151

Re: Challenges of Securing Products

Everybody and every company is facing the same challenges.

Not just in eBikes.

And getting worse not better
by john61ct
Jul 15 2021 1:13pm
Forum: EBike Technical
Topic: Any noticeable upgrade options for the cheap 1500w rear hub kits?
Replies: 3
Views: 151

Re: Any noticeable upgrade options for the cheap 1500w rear hub kits?

A truly good quality bigger battery can cost more than the total so far But totally worth it, in fact long term becomes required and more economical on an amortized basis. Get a controller compatible with CAv3 and it will derate amps/power when the motor starts overheating. Build everything so you c...
by john61ct
Jul 15 2021 2:40am
Forum: Battery Technology
Topic: Charging at less than 1/3C
Replies: 6
Views: 213

Re: Charging at less than 1/3C

0.4C is the lowest you need to go at 77°F / 25°C for longevity.

When the cell is hot you can go higher.

Close to freezing, then you must go much slower.

And other factors like discharge C-rate, and avg DoD% have a much higher impact

if those are abusive then the charge rate won't have much effect.
by john61ct
Jul 14 2021 6:05pm
Forum: Items for Sale - New
Topic: QSMOTOR,0.5-12kW Electric Hub Motor & Mid Drive Motor Manufacture China
Replies: 1437
Views: 317496

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

Every model motor you sell should have a specific model# to uniquely identify it from the start into the future.

Using a text description makes things confusing for your customers.
by john61ct
Jul 14 2021 6:02pm
Forum: Motor Technology
Topic: Low Speed, High Torque Hub Motor?
Replies: 32
Views: 759

Re: Low Speed, High Torque Hub Motor?

use gearing
by john61ct
Jul 14 2021 1:15pm
Forum: Battery Technology
Topic: Safe Lowest batteryvolyage
Replies: 8
Views: 287

Re: Safe Lowest batteryvolyage

Very few EEs actually know much about batteries
by john61ct
Jul 13 2021 7:32pm
Forum: Battery Technology
Topic: How to charge bike battery to only 80% ?
Replies: 34
Views: 859

Re: How to charge bike battery to only 80% ?

Yes when storage voltage is the goal, no precision is needed, ballpark no problem.


But the topic here is a lowered Full charge for longevity

That requires precision in the termination voltage regulation.
by john61ct
Jul 12 2021 8:46pm
Forum: Battery Technology
Topic: How to charge bike battery to only 80% ?
Replies: 34
Views: 859

Re: How to charge bike battery to only 80% ?

HVC cutoff does the same

no CV stage is needed with LI.

Poorly designed balancing circuits may need a longer finish but that's another matter.
by john61ct
Jul 12 2021 2:37pm
Forum: Items for Sale - New
Topic: ASI BAC Controllers Worldwide Vendor
Replies: 168
Views: 22147

Re: ASI BAC Controllers Worldwide Vendor

Good to hear, sounds almost too good to be true.

We really needs vendors like these to be able to use ASI.

Hey Martin how about taking on Sevcon as well?
by john61ct
Jul 10 2021 9:20pm
Forum: Battery Technology
Topic: Acceptable voltage difference in 22S/22P lithium ion pack?
Replies: 8
Views: 245

Re: Acceptable voltage difference in 22S/22P lithium ion pack?

how long is a piece of string? up to you, so long as LVC / HVC are triggered by cell voltages, it's just a matter of small reduction in pack capacity Often the delta when balancing stops is hard coded in the BMS Target for most good balancers is 5-10mV, some even claim 3mV. within ~10-20mv (.01V) of...
by john61ct
Jul 08 2021 9:39pm
Forum: EBike General Discussion
Topic: 1500w direct drive hub motor or 750w geared hub motor
Replies: 22
Views: 749

Re: 1500w direct drive hub motor or 750w geared hub motor

Sorry how do you know one is for "fat bikes"?

I see that nowhere in the listing for either motor
by john61ct
Jul 08 2021 1:34pm
Forum: EBike General Discussion
Topic: 1500w direct drive hub motor or 750w geared hub motor
Replies: 22
Views: 749

Re: 1500w direct drive hub motor or 750w geared hub motor

It's really the hill gradients on your route that are key.

The DD is stronger simpler more likely to last longer

so long as you don't have climbs that will burn it up.

Adding a CAv3 into the mix may be needed if your controller does not have a cutoff based on motor temp sensing.
by john61ct
Jul 08 2021 8:10am
Forum: Battery Technology
Topic: Charging a 72v pack from a 96v pack?
Replies: 22
Views: 556

Re: Charging a 72v pack from a 96v pack?

LFP powered Teslas are being exported to both Oz and Europe, Elon has stated in many tweets and interviews this will be expanded worldwide, otherwise Nickel will become a huge bottleneck. And I'm not saying the US **will** get smart enough fast enough on EVs, green tech, leaving FF in the ground jus...