Search found 265 matches

by leffex
Jan 06 2020 3:11pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 576
Views: 74086

Re: Li-ion cells cycle ageing

. Nice charts I love them! Thanks alot for it! MJ1 so cool new cell that give you epic and long performance life. I'm stuck with my used PFs but it could be worse if I had used my used and old Sony V3 10A capable in my latest battery build, cells who have degraded down to only 1800-2100mah which wh...
by leffex
Dec 10 2019 9:08am
Forum: Large EV General Discussion
Topic: Ideas for EV farm machinery
Replies: 59
Views: 9754

Re: Ideas for EV farm machinery

Two ideas I got apart from starting small and then taking on the harder projects. (Free house energy first before doing it at work, or commuting to work for free) A portable tower / winch using electricity or grid by cable. Just move it sideways on one end of the field and drag out the cable and sta...
by leffex
Nov 30 2019 11:09am
Forum: Battery Technology
Topic: Resuscitating new Vtc6a from complete discharge
Replies: 7
Views: 1100

Re: Resuscitating new Vtc6a from complete discharge

... Most of the packs measure around 3-4V per cell, with several packs around the 1V range and one pack that is dead flat. Like 0.04V per cell. Maybe the BMS ran it flat? ... Any suggestions welcome. The 3-4 volt ones are OK, good. But do really let go of the bad cells or use them as "learning...
by leffex
Nov 23 2019 4:07am
Forum: EBike Technical
Topic: Can someone explain this to me?
Replies: 15
Views: 2112

Re: Can someone explain this to me?

Check all wires and connectors. Try check the fuse in the battery. Most batteries have a bms that monitor power outtake and charging so that may be why it shut off after over-current protection set in in your full throttle up a hill episode. Usually this function will reset itself after a few second...
by leffex
Nov 20 2019 9:12am
Forum: EBike Technical
Topic: Sabvoton Controller Modification
Replies: 8
Views: 2245

Re: Sabvoton Controller Modification

I really wonder what benefit this does in actual numbers So two of the phases has wires going outside the Amp-sensor. If the phase wire is the same thickness and length as the original "not phase wire being bypassed" then would it be true the power would be +50%. Does this mean peaks are 5...
by leffex
Nov 19 2019 6:47am
Forum: EBike Technical
Topic: Sabvoton 72150 stuck on hall sensor test.
Replies: 9
Views: 1556

Re: Sabvoton 72150 stuck on hall sensor test.

I re-ran the test, rather than using 15-25 amps for test given current for hall sensor test, I went all out and tried 45 amps. now it passed. I changed it after realizing that at 15-25 amps it wasn't even turning the stator, just a lot of coil whine. With the other controller, even at 15 amps hall ...
by leffex
Oct 31 2019 10:25am
Forum: Battery Technology
Topic: Making a small pack 5S24P
Replies: 16
Views: 2089

Re: Making a small pack 5S24P

Making another pack. This one has 25p because the cells should measure up to 66ah and so one more is needed in each group beacuse of lower cell capacity.
Difference with this module is that I'm trying more copper in the series connections. 8 instead of 4-5

Image
by leffex
Oct 18 2019 4:16pm
Forum: Battery Technology
Topic: Samsung 40T and other cells like it?
Replies: 106
Views: 12299

Re: Samsung 40T and other cells like it?

Check out VTC5A if you haven't. I came across a graph showing it had higher voltage all the way until emptied @ 20A

Graph here 2,39 in the video:
https://www.youtube.com/watch?v=fZC_bWXrACo
by leffex
Oct 14 2019 7:50pm
Forum: Battery Technology
Topic: Samsung 40T and other cells like it?
Replies: 106
Views: 12299

Re: Samsung 40T and other cells like it?

As for 30C rated cells, don't confuse C with A, many people call 25R a 20C cell when it's a 20A cell with 8C... Hey RG I have some cool info. I tried 10a rated cells, Panasonic 2900pf cells at 24p. Build with copper wire on the series connections. In comparison to some old turnigy multistar 12C 20a...
by leffex
Sep 21 2019 10:45am
Forum: EBike Reviews & Testing
Topic: Sabvoton SVMC072150 controller review, variable regen *PICS*
Replies: 393
Views: 97814

Re: Sabvoton SVMC072150 controller review, variable regen *PICS*

So the black on the high speed low speed dongle needs to be connected directly to the negative on the 72v battery? If anyone has their high speed low speed connected and working please let me know how you did it No I don't think so. I had to change some settings turning off some in the bluetooth Th...
by leffex
Sep 20 2019 3:35am
Forum: Battery Technology
Topic: Making a small pack 5S24P
Replies: 16
Views: 2089

Re: Making a small pack 5S24P

...So the cell specs call for a .22V voltage drop between .2C and 2C rate. For 5S, that's 1.1V. Interpolating the test results for .2C load, .2*72 = 14A. The observed pack voltage drop at 14A, about .2V, so the perfect world drop is 1.1+.2=1.3V versus the observed 1.9V, a .6V delta. Plus it's reall...
by leffex
Sep 19 2019 5:37pm
Forum: Battery Technology
Topic: Making a small pack 5S24P
Replies: 16
Views: 2089

Re: Making a small pack 5S24P

you need way more copper on your bus if you wat better performance. same goes for the inbalance during load. you need way more beefy series connections. What happends when I double or tripple the bus bars? Better performance... Pack module cable are short 10awg 20cm and battery cables are oversize ...
by leffex
Sep 19 2019 11:40am
Forum: Battery Technology
Topic: New 14s battery pack, US18650VTC6 vs NCR18650GA
Replies: 190
Views: 19065

Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Ok, so if we say that i will have the pack pre-heated to 20c or so before riding off, and ignoring the very few times i'll have to park it outside in the cold, does this change anything as far as what cells are recommended? I see some of you recommend NCR, and some say forget the GA, so i'm a bit c...
by leffex
Sep 19 2019 10:48am
Forum: Battery Technology
Topic: Making a small pack 5S24P
Replies: 16
Views: 2089

Re: Making a small pack 5S24P

Just tested module one 5s24p with panasonic PF cells. They have a delta voltage between cells in the module below 0,11v at 3,95v and 150a load. Maybe I didn't balance them so it could even be lower. (Delta voltage between cells at no load was 0,005v) However. Total pack voltage at testing was 19,75v...
by leffex
Sep 17 2019 1:51pm
Forum: Battery Technology
Topic: BMS broken, damaged cells, or both?
Replies: 59
Views: 3289

Re: BMS broken, damaged cells, or both?

It would be easier if you mesured one cell group at a time, to get the voltages. ... Hi Leffex, With this low voltages of my pack.. Except for the bms, do you think any of the batteries still can be used, or should I consider it as total loss? Greetings Bas I think you should double check voltages ...
by leffex
Sep 16 2019 2:32pm
Forum: Battery Technology
Topic: Making a small pack 5S24P
Replies: 16
Views: 2089

Re: Making a small pack 5S24P

I searched for a box that fits the space I want to use and put my battery into. I can put 4 of them into my space so I started with ordering 2 boxes to try. Ordered another two from here: https://www.aliexpress.com/item/33004388619.html?spm=a2g0o.cart.0.0.77773c00w03GYq&mp=1 How do you find the ...
by leffex
Sep 16 2019 1:06pm
Forum: Battery Technology
Topic: BMS broken, damaged cells, or both?
Replies: 59
Views: 3289

Re: BMS broken, damaged cells, or both?

In this picture, the iron connection part on top is a little loose, when I press it, I can see it touch and untouch. Could that.. Be.. The.. Reason? EDIT: More pics of other side of the Pack. You need to repair it if its broken or it may cause danger in the future if you let it be. You use alot of ...
by leffex
Sep 15 2019 11:37am
Forum: Battery Technology
Topic: Pen size spot welder
Replies: 3
Views: 432

Re: Pen size spot welder

I saw it too.

I guess you still need all the normal extras
by leffex
Sep 14 2019 1:34pm
Forum: Battery Technology
Topic: Making a small pack 5S24P
Replies: 16
Views: 2089

Re: Making a small pack 5S24P

Another pack mocked up for photos: https://i.imgur.com/7MzkxJc.jpg https://i.imgur.com/q5RSl0X.jpg Module 2 pack stats: 18,5cm*7,5cm*30cm = 4162cm^3 Volume = 4,162 L 5s*26p 26F nominal 1196wh 1196wh / 4,162 L = 287wh/L Power rating 26p x 5,2a = 135,2A I'm thinking about what these modules can give i...
by leffex
Sep 01 2019 3:42pm
Forum: Motor Technology
Topic: QS-motor phase wire upgrade + Sabvoton 350A
Replies: 6
Views: 994

Re: QS-motor phase wire upgrade + Sabvoton 350A

High average consumptions is 63w energy used per km in distance

But I like that I use alot less (I have a higher efficiency) while accelerating and when using higher power but not so much in slow riding conditions rather than other positive aspects.
by leffex
Sep 01 2019 1:49pm
Forum: Motor Technology
Topic: QS-motor phase wire upgrade + Sabvoton 350A
Replies: 6
Views: 994

Re: QS-motor phase wire upgrade + Sabvoton 350A

A sidenote ... Yeah that is pretty interesting. thanks! What I mean it is pretty good to get 5% more range after fixing new cables? estimate and guesses I have RC cells but replacing with 5s24p 18650pf block. So it will get 2,4x less resistance than you calculated :P https://endless-sphere.com/foru...
by leffex
Aug 30 2019 1:08pm
Forum: Motor Technology
Topic: QS-motor phase wire upgrade + Sabvoton 350A
Replies: 6
Views: 994

QS-motor phase wire upgrade + Sabvoton 350A

Hey I want to know what benefit I get from thicker phase wires vs original thin wire in performance measures. Also positive and negative battery wires are replaced. I know the resistance in the wire is less and the voltage drop is less because of that. What performance gain in power and effeciency d...
by leffex
Aug 27 2019 12:54pm
Forum: Battery Technology
Topic: Making a small pack 5S24P
Replies: 16
Views: 2089

Re: Making a small pack 5S24P

Something like cylindrical or 6squared plastic cell holders. The ones I used was 1x4p so I added them together and broke some to make smaller pieces were needed These are very alike but not the ones I have https://vruzend.com/product/hexagonal-18650-battery-holders-3-cell/ I first thought not of usi...
by leffex
Aug 24 2019 9:59am
Forum: Battery Technology
Topic: Making a small pack 5S24P
Replies: 16
Views: 2089

Re: Making a small pack 5S24P

Work table: https://i.imgur.com/o3WyCNJ.jpg 1 of 5 pieces https://i.imgur.com/8rObp1F.jpg 5 pieces fits inside one https://i.imgur.com/OHpeWNe.jpg Finished pack: https://i.imgur.com/ONDnoex.jpg https://i.imgur.com/6ZqiWck.jpg Module pack stats: 18,5cm*7,5cm*30cm = 4162cm^3 Volume = 4,162 L 5s*24p 2,...
by leffex
Aug 05 2019 1:09pm
Forum: EBike General Discussion
Topic: Noob expat in Sweden attempting a first build
Replies: 11
Views: 793

Re: Noob expat in Sweden attempting a first build

just search elcykelkit nor elcykelbatteri and you will find front wheel motor or battery in Sweden with warranty.

Tax for buying outside eu is + 3-8% for ebike parts into Sweden and +25% tax on that aswell as +100 sek fee for handling.