Search found 77 matches

by eikido
Oct 27 2020 2:14am
Forum: Battery Technology
Topic: DC Load test large battery packs. Rheostat?
Replies: 13
Views: 820

Re: DC Load test large battery packs. Rheostat?

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?
by eikido
Oct 23 2020 2:58am
Forum: Battery Technology
Topic: DC Load test large battery packs. Rheostat?
Replies: 13
Views: 820

Re: DC Load test large battery packs. Rheostat?

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...
by eikido
Oct 18 2020 4:52am
Forum: Battery Technology
Topic: DC Load test large battery packs. Rheostat?
Replies: 13
Views: 820

DC Load test large battery packs. Rheostat?

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...
by eikido
Jun 12 2020 9:45am
Forum: E-Bike Technical
Topic: JST-SM Crimp Tool
Replies: 43
Views: 4386

Re: JST-SM Crimp Tool

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...
by eikido
Jun 12 2020 7:18am
Forum: E-Bike Technical
Topic: JST-SM Crimp Tool
Replies: 43
Views: 4386

Re: JST-SM Crimp Tool

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...
by eikido
Apr 13 2020 2:35am
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 2037

Re: Help me troubleshoot this pack please. How are these voltages?

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 ...
by eikido
Apr 12 2020 3:28pm
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 2037

Re: Help me troubleshoot this pack please. How are these voltages?

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
by eikido
Apr 12 2020 6:23am
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 2037

Re: Help me troubleshoot this pack please. How are these voltages?

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.
by eikido
Apr 12 2020 4:11am
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 2037

Re: Help me troubleshoot this pack please. How are these voltages?

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.
by eikido
Apr 12 2020 2:49am
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 2037

Re: Help me troubleshoot this pack please. How are these voltages?

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...
by eikido
Mar 24 2020 6:04am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1220
Views: 181724

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

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...
by eikido
Mar 23 2020 5:29pm
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 2037

Re: Help me troubleshoot this pack please. How are these voltages?

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...
by eikido
Mar 23 2020 4:39am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1220
Views: 181724

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

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...
by eikido
Mar 22 2020 4:16pm
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 2037

Re: Help me troubleshoot this pack please. How are these voltages?

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.
by eikido
Mar 22 2020 12:28pm
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 2037

Re: Help me troubleshoot this pack please. How are these voltages?

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. ...
by eikido
Mar 22 2020 10:41am
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 2037

Re: Help me troubleshoot this pack please. How are these voltages?

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...
by eikido
Mar 22 2020 8:21am
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 2037

Re: Help me troubleshoot this pack please. How are these voltages?

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...
by eikido
Mar 22 2020 3:25am
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 2037

Re: Help me troubleshoot this pack please. How are these voltages?

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...
by eikido
Mar 21 2020 4:05am
Forum: General Discussion
Topic: Active energy transfer balancing
Replies: 38
Views: 3317

Re: Active energy transfer balancing

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...
by eikido
Mar 20 2020 5:46pm
Forum: Battery Technology
Topic: Test a battery pack. How can i easily create a high amp load?
Replies: 15
Views: 1241

Re: Test a battery pack. How can i easily create a high amp load?

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
by eikido
Mar 20 2020 5:05pm
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 2037

Re: Help me troubleshoot this pack please. How are these voltages?

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...
by eikido
Mar 20 2020 11:28am
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 2037

Re: Help me troubleshoot this pack please. How are these voltages?

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...
by eikido
Mar 20 2020 7:38am
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 2037

Re: Help me troubleshoot this pack please. How are these voltages?

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/...