Search found 1932 matches

by Hummina Shadeeba
Feb 26 2021 12:27pm
Forum: Battery Technology
Topic: 2020/21 What's the best 100A Peak Pack?
Replies: 77
Views: 2447

Re: 2020/21 What's the best 100A Peak Pack?

A couple steel screws doesn’t seem a big deal and was surprised to find the kweld uses them. If they’re big enough maybe the conductance creeps up to equivalent to a decent conductor.

Gotta buy that cheap precision resistance tester.
by Hummina Shadeeba
Feb 26 2021 10:21am
Forum: Battery Technology
Topic: 2020/21 What's the best 100A Peak Pack?
Replies: 77
Views: 2447

Re: 2020/21 What's the best 100A Peak Pack?

What’s wrong with using screws or threads as conductors? I’ve seen them used a lot
by Hummina Shadeeba
Feb 24 2021 6:59pm
Forum: E-Vehicles General Discussion
Topic: Program some anti theft?
Replies: 2
Views: 82

Re: Program some anti theft?

Be easy enough if its open source like you say. Just start to learn how to code. With the Vesc being open source how hard would it be to program it to require specific input from the motor when it first came on, such as going backwards three paces, otherwise would lock the wheel? I dont know how to...
by Hummina Shadeeba
Feb 23 2021 1:54pm
Forum: E-Vehicles General Discussion
Topic: Program some anti theft?
Replies: 2
Views: 82

Program some anti theft?

With the Vesc being open source how hard would it be to program it to require specific input from the motor when it first came on, such as going backwards three paces, otherwise would lock the wheel?
by Hummina Shadeeba
Feb 22 2021 2:38pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 192771

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

Hi yaw I just placed an order for the K-weld from Frank on the 12th and can’t wait to get it! Like a kid waiting on Christmas About how long does it take to a package from Germany to the US? I opted for the 2nd option that gives your package the Air ride vs the water ride but just curious how the C...
by Hummina Shadeeba
Feb 21 2021 11:19am
Forum: Battery Technology
Topic: getting cells up to 140f
Replies: 7
Views: 277

Re: getting cells up to 140f

I can’t find an example of nasa getting the cell to 140f in your link. 140f isn’t going to send a cell into thermal runaway. If I do an IR or capacity test before and after exposing it to the heat I’ll know if the cell has degraded enough to notice. I don’t need safety advice and know the danger of ...
by Hummina Shadeeba
Feb 20 2021 11:50am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 192771

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

Can weld .2mm copper if it’s slotted. Depends on the cell but the 30q 18650 were no problem at 80j.

Can do .1mm copper no problem with much less joules
by Hummina Shadeeba
Feb 20 2021 11:46am
Forum: Battery Technology
Topic: getting cells up to 140f
Replies: 7
Views: 277

Re: getting cells up to 140f

how much degradation would happen in ion or iron cells that maybe touch this temp for a couple minutes? Do you know the "BTU", friend? A British thermal unit is a measure of heat. Described as the amount of heat needed to raise one pound of water at maximum density (1/1) through one degre...
by Hummina Shadeeba
Feb 19 2021 2:52pm
Forum: Battery Technology
Topic: Battery design advice required
Replies: 19
Views: 514

Re: Battery design advice required

one nickel-plated copper bus bar measured 2.4mΩ ... doubling length only 2.6mΩ im confused by what youre saying...i assume doubling the length of anything is going to double the resistance produced by it. the connections maybe are a bigger loss than the distance but none the less doubling your wire...
by Hummina Shadeeba
Feb 19 2021 11:40am
Forum: Battery Technology
Topic: getting cells up to 140f
Replies: 7
Views: 277

getting cells up to 140f

how much degradation would happen in ion or iron cells that maybe touch this temp for a couple minutes? i imagine it's not good. id like to sink cells in https://www.instructables.com/DIY-Material-Guide:-Polymorph-Plastic--a-thermal-/ this seemingly lowest temperature meltable plastic. i think i cou...
by Hummina Shadeeba
Feb 19 2021 10:47am
Forum: Battery Technology
Topic: Battery design advice required
Replies: 19
Views: 514

Re: Battery design advice required

Yes, it is 30% more nickel and 30% more resistance. My calculations showed a 39% increase in losses (1.28 Watt vs 0.92 Watt). Are you sure? My AideTek SM8124A (4-wire) tests with nickel-plated copper confirmed that there would be nowhere near a 30% increase in resistance with a 30% increase in leng...
by Hummina Shadeeba
Feb 17 2021 4:52pm
Forum: Battery Technology
Topic: Weld 2P battery in an X pattern?
Replies: 8
Views: 286

Re: Weld 2P battery in an X pattern?

why you space your cells apart?
by Hummina Shadeeba
Feb 17 2021 4:23pm
Forum: Battery Technology
Topic: Battery design advice required
Replies: 19
Views: 514

Re: Battery design advice required

i dont think people make batteries in a rectangular pattern like the drawing of the original poster. maybe they do. a waste of space and not as strong as the triangular id think in most cases. rather make a solid smaller block unless had mounting posts between. if its triangular cant do the x patter...
by Hummina Shadeeba
Feb 17 2021 3:25pm
Forum: Battery Technology
Topic: Battery design advice required
Replies: 19
Views: 514

Re: Battery design advice required

looks like just as much nickel needed doing an "x" as done when doing the typical square IF you orient all the cells staggered instead of in rectangular pattern as in your pic. dont know why you write .07% which is a tiny amount. doing the x on the rectangularly arranged cells would be 30%...
by Hummina Shadeeba
Feb 17 2021 9:52am
Forum: Battery Technology
Topic: 18650 spot welding -how to- ULTIMATE REPOSITORY
Replies: 790
Views: 195758

Re: 18650 spot welding -how to- ULTIMATE REPOSITORY

it saves times and nickel. seems a good idea but never see people doing it.
by Hummina Shadeeba
Feb 17 2021 9:47am
Forum: Battery Technology
Topic: Weld 2P battery in an X pattern?
Replies: 8
Views: 286

Re: Weld 2P battery in an X pattern?

good idea. the amount of current going between paralleled cells is tiny, just one weld on the x is good enough.
by Hummina Shadeeba
Feb 16 2021 11:16am
Forum: Battery Technology
Topic: 18650 spot welding -how to- ULTIMATE REPOSITORY
Replies: 790
Views: 195758

Re: 18650 spot welding -how to- ULTIMATE REPOSITORY

You can get nickel in different widths, so .2x15 or something wider than typical .2x8 or around that. Or u can just stack thinner .15mm stuff and there’s no need to be able to weld thick stuff really
by Hummina Shadeeba
Feb 15 2021 3:56pm
Forum: EBike General Discussion
Topic: Best material for battery impact shock absorption?
Replies: 31
Views: 2455

Re: Best material for battery impact shock absorption?

If u sink them in resin then u don’t have to worry about them being banged around and I think you’ll be better able to transfer heat through the resin then stagnant air. U could add a mounting fixture to the potting. Could pot them in a low temp theroform resin and extract them for recycling later. ...
by Hummina Shadeeba
Feb 13 2021 4:42pm
Forum: EBike General Discussion
Topic: Figuring 0-30mph based on amperage ..
Replies: 3
Views: 145

Figuring 0-30mph based on amperage ..

With this esc doing 140 amps https://www.discoverzesc.com/raiden7-series I’m wondering how fast will it get a rider from 0-30mph. Assuming 200lbs rider. A kv that get you just up to that top speed. And the powered wheel a 20” bike wheel or an 84mm skate hub motor. I forget how to convert kv to kt to...
by Hummina Shadeeba
Feb 11 2021 3:31pm
Forum: Battery Technology
Topic: 18650 spot welding -how to- ULTIMATE REPOSITORY
Replies: 790
Views: 195758

Re: 18650 spot welding -how to- ULTIMATE REPOSITORY

how bad is it to have done this already?
by Hummina Shadeeba
Feb 11 2021 3:02pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 192771

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

Being America I don’t actually find metric stuff just imperial so really I’ve been doing 5mil or .005” sheet which is .127mm. No problem. Good enough and my quest for more copper is over.

I use the included probes and if they start getting stuck I file them to their original rounded point.
by Hummina Shadeeba
Feb 11 2021 2:38pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 192771

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

You can go to 100j but that might still not work since the reason why copper is so hard to weld is its ability to conduct the heat away from the weld spot. When you set more joules that basicly means longer pulse time and that means copper has longer time to spread the heat away so at some point yo...
by Hummina Shadeeba
Feb 11 2021 10:33am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 192771

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

thanks and i lowered battery soc and can now weld with half a meter of wiring including the probes and dont get an overcurrent. I have no problem getting good welds with .1mm copper using only 25 joules on the negative and 50 on the positive A123 green cells. i imagine .2mm copper wouldnt be too har...
by Hummina Shadeeba
Feb 09 2021 8:28pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1288
Views: 192771

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

I’m saying if i shorten my battery wires too much I get “over current”, but when I lengthen them, to like 2meters including probes now, I have too much inductance to do more than maybe 1200 amps as shows on their posted chart. I want to do more. How?
https://imgur.com/a/qu13QBy
by Hummina Shadeeba
Feb 09 2021 11:29am
Forum: Battery Technology
Topic: 18650 spot welding -how to- ULTIMATE REPOSITORY
Replies: 790
Views: 195758

Re: 18650 spot welding -how to- ULTIMATE REPOSITORY

Where’s the best spot to weld on the cell? Center or the edge?