Search found 30 matches

by takyka
Dec 24 2019 5:14pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46909

Re: Li-ion cells cycle ageing

Docware,

When you decide to finish cycle testing, could you please make a full cycle test as per datasheet (for me at least on the PF )? Would be good to see if full capacity will have the same degradation than the voltage limited one...

Thank you for all your efforts doing these tests!

T.
by takyka
Dec 03 2019 3:05am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46909

Re: Li-ion cells cycle ageing

Thank you!

T.
by takyka
Dec 01 2019 11:24am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46909

Re: Li-ion cells cycle ageing

Docware,

What is your DCIR measurement methodology? I want to check my 4 years old battery for comparison.

Thx,


T.
by takyka
Nov 26 2019 9:29am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46909

Re: Li-ion cells cycle ageing

Cephalotus wrote:
Nov 26 2019 6:36am
I do not believe that. PF always lost 10-15% capacity early and stabilised after that.
This is what I'm hoping, but yet to see...

T.
by takyka
Nov 26 2019 9:27am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46909

Re: Li-ion cells cycle ageing

170 cells, that´s different story. If possible try to have lower DOD and charging current. DOD for PF in this testing is cca 73 %, which is quite high. Both PF and GA are now slowing down capacity decline. We should also realize the we are comparing PF and GA to 29E and M36, members „Best of“ team....
by takyka
Nov 25 2019 4:51pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46909

Re: Li-ion cells cycle ageing

takyka, those parameters are behind gentle utilization, so no such big surprise. PF is obviously not the best choice, don´t understand your nostalgia for it. You have better options like 29E or newly M29. Or M36. I don’t have nostalgia, just arround 170 cells in two packs. With (the original) life ...
by takyka
Nov 25 2019 3:16am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46909

Re: Li-ion cells cycle ageing

Docware, First, I would like to thank you for your efforts, I follow it with great interest! I would vote for longer test run, as I'm not the one who willing to spend on new batteries as long the present one works, just because in a few years a better, fancier is out... For me, would be good to see ...
by takyka
Apr 03 2019 3:31am
Forum: Battery Technology
Topic: Cell level fuse: Different awg wire on positive and negative?
Replies: 7
Views: 636

Re: Cell level fuse: Different awg wire on positive and negative?

Because you should not think about 24AWG as fuse wire for low current cell. It would melt only over 30A I guess.
In the video he was using glass fuses on positive terminal for overcurrent protection purposes...

T.
by takyka
Apr 01 2019 5:49am
Forum: Battery Technology
Topic: Esk8 battery build 12s7p
Replies: 6
Views: 714

Re: To fuse or not to fuse? Evaluate my build plan please

Using fuse wire helps you to keep heat exposure and can temperature low during construction. This is important on negative side. Also important to solder far from the center, as it is considered the most sensitive area.

T.
by takyka
Mar 09 2019 4:09am
Forum: Battery Technology
Topic: DIY HI POWERED PACK: First time, General questions
Replies: 60
Views: 3762

Re: DIY HI POWERED PACK: First time, General questions

Hello, I prefer fuse wired battery instead spot welding rigidly the cells. If it is made carefully, no evidence, spot welding would be less harmful solution on the cells, but results a less safe pack. Here is my 2nd build: https://endless-sphere.com/forums/viewtopic.php?f=14&t=92645 More info you ca...
by takyka
Jan 24 2019 7:02am
Forum: Battery Technology
Topic: 18650 Battery Pack Build
Replies: 8
Views: 667

Re: 18650 Battery Pack Build

The thick wire you can safely solder to the positive terminals directly. Then you solder the thin wire from negative terminals to this "bus bar". This way you can eliminate half of the fuse wires.

T.
by takyka
Nov 10 2018 1:56pm
Forum: Battery Technology
Topic: Tesla Model S battery upgrade
Replies: 0
Views: 485

Tesla Model S battery upgrade

Hello,
Just find a fresh video about P90D to P100D battery pack upgrade:
https://youtu.be/cUyIsejp0cE

T.
by takyka
Oct 14 2018 12:35pm
Forum: Battery Technology
Topic: DIY ajustable current source : test cell fuse wire
Replies: 18
Views: 1531

Re: DIY ajustable current source : test cell fuse wire

I use dia 0,3mm copper wire as fuse, for my packs, built from Panasonic PF cells. My design criteria was, individual cells should be able to blow their own fuse any case. My boundary conditions were: 1. At 10A (max current of PF) the wire should be warm, but still touchable by naked fingers. 2. At r...
by takyka
May 30 2018 9:27am
Forum: Battery Technology
Topic: Yet another 18650 battery build.
Replies: 77
Views: 7874

Re: Yet another 18650 battery build.

Flippy, You are wrong! Appropirately dimensioned fuse wire does not generate significant losses. My fuse wires are 0,3mm diameter and 10mm long. The measured resistance is 3,5mOhm. In comparison, the Pana PFs I use, has ~30mOhm internal resistance. ( by the way, how much is a spot welded nickel stri...
by takyka
Feb 18 2018 4:01pm
Forum: Battery Technology
Topic: My 2nd Fuse link 18650 battery build
Replies: 6
Views: 1476

Re: My 2nd Fuse link 18650 battery build

After assembling the pack, I made preparations for a real life test run of the battery. I added temporary main wires and simple car fuses. I placed the pack in a 16" plastic toolbox. To monitor the cells, I used a temp meter and a Lipo alarm. IMG_2568(1).JPG The load is a Haswing Protruar 2HP 1,2kW ...
by takyka
Feb 18 2018 2:53pm
Forum: Battery Technology
Topic: My 2nd Fuse link 18650 battery build
Replies: 6
Views: 1476

Re: My 2nd Fuse link 18650 battery build

Thx!

I use dia 0,3mm copper wire for fuse link.
by takyka
Feb 06 2018 9:13am
Forum: Battery Technology
Topic: My 2nd Fuse link 18650 battery build
Replies: 6
Views: 1476

Re: My 2nd Fuse link 18650 battery build

I machined the holder plates from some leftover pieces of plastic. akkufedlap.jpg Batteries are placed to "bottom" half: akkuk_a_tartoban.jpg Here things were happening so fast, I forgot to take more pictures during building. akku2.jpg As you can see, thick wire "busbar" soldered to the + terminals,...
by takyka
Jan 31 2018 9:49am
Forum: Battery Technology
Topic: My 2nd Fuse link 18650 battery build
Replies: 6
Views: 1476

Re: My 2nd Fuse link 18650 battery build

So dia 0,3mm fuse wire will be fine. This case I decided to use BMS. I need a carefree battery. As the cells don't have willingness to drift away much, I ordered a basic 60A 2,5-4,2V BMS with 50mA ballancing capability. I ordered a battery switch and a circuit breaker, but undecided yet, to use the ...
by takyka
Jan 31 2018 9:49am
Forum: Battery Technology
Topic: My 2nd Fuse link 18650 battery build
Replies: 6
Views: 1476

My 2nd Fuse link 18650 battery build

Hello, After almost three years of my first battery taken into use, I started to build a new battery. https://endless-sphere.com/forums/download/file.php?id=215011&mode=view I consider the 1st attempt as a great success. It is a 6S4P NCR18650PF pack soldered with fuse links at the negative terminal....
by takyka
Sep 02 2017 8:33am
Forum: Battery Technology
Topic: soldering vs spot welding debate
Replies: 75
Views: 17399

Re: soldering vs spot welding debate

qwerkus wrote: Do you happen to have any build fotos of that configuration ? would love to see how it looks like before diving into it.
Take a look on this:
https://endless-sphere.com/forums/viewt ... 9#p1286723

T.
by takyka
May 10 2017 2:01am
Forum: Battery Technology
Topic: Fuse-wire for individual cells, DIY Tesla style
Replies: 186
Views: 40127

Re: Fuse-wire for individual cells, DIY Tesla style

The PFs has no extra protection built in.

Looking like this:
http://www.bazaargadgets.com/image/cach ... 00x800.jpg
You can see how the cap is made...

T.
by takyka
May 09 2017 6:50am
Forum: Battery Technology
Topic: Fuse-wire for individual cells, DIY Tesla style
Replies: 186
Views: 40127

Re: Fuse-wire for individual cells, DIY Tesla style

Spinningmagnets, I'm quite sure. At least in case of PFs. The positive terminal "button" is not solid one, but the contacting surface is connected to the main body by the means of three tabs equally spread along the circumfence. Very small mass to heat up and cool down during soldering, so it is a f...
by takyka
May 09 2017 1:53am
Forum: Battery Technology
Topic: Fuse-wire for individual cells, DIY Tesla style
Replies: 186
Views: 40127

Re: Fuse-wire for individual cells, DIY Tesla style

Hello, I built my kick scooter pack exactly like in the title. 6S4P Pana PF cells. Max. current draw (in line with cell capability) is 40A. Added benefit of the fuse wire is the lowest possible solder heat impact on the cells negative terminal. kickscooter_battery2.jpg kickscooter_battery1.jpg T.
by takyka
Dec 19 2015 2:23pm
Forum: Stand-up E-scooters and E-skateboards
Topic: Converting my Oxelo Town 9 EasyFold Scooter
Replies: 56
Views: 15983

Re: Converting my Oxelo Town 9 EasyFold Scooter

Hello, Try download from here: http://s3.toldacuccot.hu/letoltes?sid=c1c60aa7af2bb7b2c8c8aac5c33c0aa3&ros=8f14e45fce I'm using HTD-5 belt, width is 9mm. Yes, I drilled holes to wheel "spokes". If you check the big sprocket, you see there is a middle part. I used it for alignment, then cuted it out. T.
by takyka
Dec 17 2015 4:00am
Forum: Stand-up E-scooters and E-skateboards
Topic: Converting my Oxelo Town 9 EasyFold Scooter
Replies: 56
Views: 15983

Re: Converting my Oxelo Town 9 EasyFold Scooter

Hi,

Sorry for long silence. I have tried to upload step files here, no luck. Is anybody know how to do it?
T.
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