Endless Sphere

DogDipstick wrote: ↑

Oct 24 2020 8:52am

I built one arger than DrBass.


Alot more powerful. Some 30 Kw. i used a CA3 datalogger, 500A shunt, and 30kw of ( 1100w-1700w) strip heaters. About 30 of them.

Oh man, I'm so glad i asked all of you guys.

DogDipstick, what ohms are your heater loads?

It doesnt look like that rheostat will stress your 60v packs to 3kW ? ..(50A) For that 3kW you would need a 1.2ohm resistance load, but that site doesnt list a 1 ohm resistor above 2kW capacity.. ( 34A max @ 60V)...but fine for the 0.2 C tests. Maybe another vendor ? Or,..this is another option.. h...

Bump anyone?

I have large battery packs, up to 60v@36Ah and output around 2000-3000w, which i would like to troubleshoot by loading them. I'm thinking a variable rheostat + Battery Coulometer https://www.aliexpress.com/item/33003268665.html?spm=a2g0o.productlist.0.0.1e486bf7G9ytVD&algo_pvid=900dedeb-d0b5-45c...

imho those are the best crimpers you can get: http://www.amazon.com/Engineer-PA-09-Micro-Connector-Crimpers/dp/B002AVVO7K/ref=sr_1_1?ie=UTF8&qid=1432123464&sr=8-1&keywords=jst+crimp+tool they make excellent crimps. no ratching mechanism or other goofy stuff. just plain crimping. but hig...

imho those are the best crimpers you can get: http://www.amazon.com/Engineer-PA-09-Micro-Connector-Crimpers/dp/B002AVVO7K/ref=sr_1_1?ie=UTF8&qid=1432123464&sr=8-1&keywords=jst+crimp+tool they make excellent crimps. no ratching mechanism or other goofy stuff. just plain crimping. but hig...

And sincpower is also not all that bad. http://www.sincbattery.org/index.html What evidence do you have for that statement? They are in many ebikes and scooters and have been around for many years and they don't try to hide their brand like other fake chinese factories. But yes, i haven't seen any ...

It's ok, i will try myself.
I'm not expecting any help, i only appreciate any help i get.
I'm learning and i think this is the best way to learn. I wouldn't do the same on a big pack with loads of MJ1's.

And sincpower is also not all that bad.
http://www.sincbattery.org/index.html

docware wrote: ↑

Apr 12 2020 5:49am

Well, this lesson brings advice : don´t waste your time with noname chinese cells and throw them to the hazardous scrap.

Are you in a bad mood?
Please don't take it out on me.

docware wrote: ↑

Apr 12 2020 4:03am

Eikido, it seems to me that your effort to build battery from noname chinese cells is wasting of money and time.

I'm not building it, i'm troubleshooting it for a friend.
It's a great way to learn.
Everybody starts from 0.

I'm having issues finding the bad cell(s). Here is a video: https://www.youtube.com/watch?v=pVJT2L6f1Vg I load the battery pack and monitor two cell groups. The bad cell group 11 (which is actually group 3) and some random one. It is very clear that cell group 3 (11) is going out of balance when loa...

I came to read this thread just to look for this question and you answered it. But i would like to know what pulse you and the rest of you find is acceptable (for let's say 0.15 mm nickel)? The longer the pulse=the lower burst current the battery provide. Would you say, the higher the current the l...

Cell group 11 confirmed bad. I'm lucky and managed to borrow a DC electronic loader. When i reach ~3.488v then cell group 11 starts to get too much out of balance from the rest cell groups. Like 0.16-0.20v below the strongest cell group and the BMS shuts off. Everything is fine from full charge (4.1...

tatus1969 A couple questions to tatus1969: 1. With the kweld the adjustment for different welds is in energy J. I'm just wondering if there will be a difference in the weld energy used in each weld when your battery is fully charged and when the battery is close to the LVC? or will the setting of 2...

zeccato wrote: ↑

Mar 22 2020 1:17pm

eikido wrote: ↑

Mar 22 2020 3:25am

I think that after 3 or 4 unloaded charges it will normalize, if charged up to at least 4v is fine, the difference is minimal.
In my opinion, I wouldn't do anything,
just sometimes the balance.
You use it for ebike?

It's for a 500w electric scooter. Burst >1000w.

Does the battery do less miles (km) than before? Brand new. Charged full one time. I do have warranty but it's going to cost more to get it shipped back. Plus I have all equipment to rebuild it. K weld, pure nickel, kapton tape etc. Plus it's fun and educational so I appreciate all your guys help. ...

After i fully charged the pack (cell 11=4.04v) and waited one day, cell 11 dropped to 4.00v (compared to highest cell voltage of 4.13v). So i balanced cell 11 to 4.13v and after one day, it dropped to 4.06v. The other cells have held their voltage for two days (one cell dropped 0.02v which should b...

Is that a cell or a group? Yes indicates weakness, IMO needs atomized load testing likely replacement unless you're willing to let that cell / group capacity dictate the (much reduced) range of the whole pack It's a group. It's 6P. I will disassemble the whole pack, find the bad cell and rebuild it...

After i fully charged the pack (cell 11=4.04v) and waited one day, cell 11 dropped to 4.00v (compared to highest cell voltage of 4.13v). So i balanced cell 11 to 4.13v and after one day, it dropped to 4.06v. The other cells have held their voltage for two days (one cell dropped 0.02v which should be...

john61ct gave me some nice tips about those active balancers and i'm very eager to get one. Thank you john61ct!! I've been investigating a little bit and found out that those cheaper ones are not really good since they transfer energy between each cells, so cell 1 cannot transfer to cell 6. Yes afte...

ginekolog wrote: ↑

Mar 20 2020 4:53pm

Buy 4 50W 12V halogent bulbs, connect in series and you get 200W 48V 5A load. Thats how I test my batt.

Awesome! I will try this It will be a cheap test. Thanks.
So the resistance over one 12v, 50w halogen bulb is really low?
Something like 2.5 ohms (2.5x4=10 ohms)?

I=48v/10ohms=4.8A

I'm very sorry @john61ct, i missed those balance chargers in the previous post, sorry Those aren't "balance chargers". They are "balancers" or sometimes "not protective BMS". Some do not require working with a charge source at all, they shuttle excess energy from the h...

Thanks all. I'm very sorry @john61ct, i missed those balance chargers in the previous post, sorry. I will try to get one of them. Here are measurements fully charged. 1: 4.13 2: 4.12 3: 4.11 4: 4.10 5: 4.13 6: 4.12 7: 4.12 8: 4.13 9: 4.13 10: 4.12 11: 4.04 12: 4.12 13: 4.13 I guess 11 doesn't look g...

Might be best to leave the BMS alone and use a dedicated balancer unit that will do a better job at that function anyway I see. Since there aren't any 13s balancers, what is your recommendation to balance? Use something like the IMAX B6 and balance 6 cell parallels at a time? https://www.skyrc.com/...

Thanks for everything.
Yes i'm from Sweden