Search found 307 matches

by garolittle
Nov 16 2019 4:23pm
Forum: Battery Technology
Topic: Internal Resistance for pack of LG HG2 cells
Replies: 22
Views: 321

Re: Internal Resistance for pack of LG HG2 cells

john61ct wrote:
Nov 16 2019 3:59pm


But phase changing sure takes things to another level.

We strongly recommend AllCell Technologies. Great product and excellent customer service. 8)
by garolittle
Nov 16 2019 3:55pm
Forum: Battery Technology
Topic: Internal Resistance for pack of LG HG2 cells
Replies: 22
Views: 321

Re: Internal Resistance for pack of LG HG2 cells

Got an idea. If you can measure charging current or if you know the charging current, you can calculate internal resistance from the charging current value and voltage difference on the cell. You just need to have DMM with resolution mV or better 0,1 mV and connect to any cell´s balance wiring. So ...
by garolittle
Nov 16 2019 2:25pm
Forum: Battery Technology
Topic: Internal Resistance for pack of LG HG2 cells
Replies: 22
Views: 321

Re: Internal Resistance for pack of LG HG2 cells

john61ct wrote:
Nov 15 2019 12:16pm
can you link to where you bought that pack?
www.allcelltech.com.
by garolittle
Nov 15 2019 4:00pm
Forum: Battery Technology
Topic: Internal Resistance for pack of LG HG2 cells
Replies: 22
Views: 321

Re: Internal Resistance for pack of LG HG2 cells

Yes sir. I will run the test on Sunday and post the results by Sunday night or Monday morning. Thank you again for all of your ideas.
by garolittle
Nov 15 2019 9:12am
Forum: Battery Technology
Topic: Internal Resistance for pack of LG HG2 cells
Replies: 22
Views: 321

Re: Internal Resistance for pack of LG HG2 cells

I really appreciate all of the responses. I have learned many things and will use the “charger method” references above. Good point about the individual cells. Also, it is true I am only looking for the IR of the cell string (with 20 in parallel). Either way, I appreciate the responses from both of ...
by garolittle
Nov 14 2019 8:32pm
Forum: Battery Technology
Topic: Internal Resistance for pack of LG HG2 cells
Replies: 22
Views: 321

Re: Internal Resistance for pack of LG HG2 cells

john61ct wrote:
Nov 14 2019 8:21pm
DMM is a Digital Multi-Meter

Getting IR for benchmarking changes from now vs later is very useful.
Roger that and thanks!
by garolittle
Nov 14 2019 8:13pm
Forum: Battery Technology
Topic: Internal Resistance for pack of LG HG2 cells
Replies: 22
Views: 321

Re: Internal Resistance for pack of LG HG2 cells

Got an idea. If you can measure charging current or if you know the charging current, you can calculate internal resistance from the charging current value and voltage difference on the cell. You just need to have DMM with resolution mV or better 0,1 mV and connect to any cell´s balance wiring. Hey...
by garolittle
Nov 14 2019 5:58pm
Forum: Battery Technology
Topic: Internal Resistance for pack of LG HG2 cells
Replies: 22
Views: 321

Re: Internal Resistance for pack of LG HG2 cells

I do not believe the 2.81 is correct but I want to double check to be sure. Thanks for any ideas. Gary
by garolittle
Nov 14 2019 5:57pm
Forum: Battery Technology
Topic: Internal Resistance for pack of LG HG2 cells
Replies: 22
Views: 321

Re: Internal Resistance for pack of LG HG2 cells

docware wrote:
Nov 14 2019 5:51pm
garolittle,what is purpose of this pack measurement ?
I want to verify the BMS data regarding the internal resistance. I have an Orion jr. BMS and it is showing a higher reading than normal. Typical IR for this pack has been .8 to .9 but the recent reading was 2.8.
by garolittle
Nov 14 2019 2:49pm
Forum: Battery Technology
Topic: Internal Resistance for pack of LG HG2 cells
Replies: 22
Views: 321

Re: Internal Resistance for pack of LG HG2 cells

PaulD wrote:
Nov 14 2019 2:41pm
To be clear, you want to measure the resistance of each 14S1P string? Or each 1S20P group? Not sure how your pack is configured.
My apologies. Since the 20 in parallel act as a single cell in terms of voltage, I want to measure the internal resistance of each sting of 20
by garolittle
Nov 14 2019 1:13pm
Forum: Battery Technology
Topic: Internal Resistance for pack of LG HG2 cells
Replies: 22
Views: 321

Internal Resistance for pack of LG HG2 cells

Background: I have a 14S/20P pack of LG HG2 cells and need to measure the internal resistance of each cell string. Can I use the process discussed at the 4-minute mark of the YouTube link below except use a 20-olm resistor instead of a 1-olm resistor? Thanks!

https://youtu.be/av38iBxcOgQ
by garolittle
Nov 01 2019 12:02pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 949
Views: 108203

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

flippy wrote:
Oct 31 2019 11:27am
garolittle wrote:
Oct 31 2019 11:11am
I am one of those who dumped the Sunkko after using the kWeld. 8)
i stopped using after the transformer blew up all over the workbench.
Wow. Glad you were not hurt!
by garolittle
Oct 31 2019 11:11am
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 949
Views: 108203

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

My POS dead Sunnko was $250. My new KWeld will be $234. The real question is will they perform better? Never owned a Sunkko, but I can tell that I have quite a few customers who told me that they have dumped their Sunkko after having used kWeld 8) I am one of those who dumped the Sunkko after using...
by garolittle
Oct 22 2019 7:15pm
Forum: Battery Technology
Topic: Charging and Balancing Questions for LG HG2 pack (14S/20P)
Replies: 10
Views: 398

Re: Charging and Balancing Questions for LG HG2 pack (14S/20P)

No, really separate parameters. Ah capacity will help support amps discharge rate, lower stress on the cells, and of course range. The loads - in this case motor + controller - will determine what voltage you want, taking desired top speed into account. But going faster drastically lowers range. So...
by garolittle
Oct 22 2019 12:05pm
Forum: Battery Technology
Topic: Charging and Balancing Questions for LG HG2 pack (14S/20P)
Replies: 10
Views: 398

Re: Charging and Balancing Questions for LG HG2 pack (14S/20P)

Thanks again for all of the great responses. Would higher numbers of cells in Parallel make lower voltage strings acceptable? For example, if I used 14S/30P instead of 14S/20P, would this allow for lower voltages per cell string? Just curious. Thanks. Gary
by garolittle
Oct 21 2019 7:38pm
Forum: Battery Technology
Topic: Charging and Balancing Questions for LG HG2 pack (14S/20P)
Replies: 10
Views: 398

Re: Charging and Balancing Questions for LG HG2 pack (14S/20P)

Thank you. I really do appreciate the response. Gary.
by garolittle
Oct 21 2019 5:40pm
Forum: Battery Technology
Topic: Charging and Balancing Questions for LG HG2 pack (14S/20P)
Replies: 10
Views: 398

Re: Charging and Balancing Questions for LG HG2 pack (14S/20P)

The minimum cell voltage of 2.9V isn't conservative enough for my taste. I would say around 3.0V - 3.1V per cell for the BMS and 3.2V - 3.3V per cell or 44.8V total pack voltage for the controller's low voltage cutoff. I know it is not a perfect analogy, but Tesla recommends keeping the State of Ch...
by garolittle
Oct 19 2019 1:58pm
Forum: Battery Technology
Topic: Charging and Balancing Questions for LG HG2 pack (14S/20P)
Replies: 10
Views: 398

Re: Charging and Balancing Questions for LG HG2 pack (14S/20P)

cell variance at .01V should be the trigger for balancing to start. 20-30mV should be where they end up. LVC really should be higher if at all possible for longevity, voltage sag depends on your peak loads should end up no lower than 3.4Vpc after resting bounceback. Thanks Sir. Really appreciate th...
by garolittle
Oct 18 2019 2:12pm
Forum: Battery Technology
Topic: Charging and Balancing Questions for LG HG2 pack (14S/20P)
Replies: 10
Views: 398

Re: Charging and Balancing Questions for LG HG2 pack (14S/20P)

You haven't mentioned it but if you also charge to a max of 4.05 to 4.1V per cell, that will also net you more cycles. A cell string voltage difference of .03V to .05V seems high. I would shoot for 0.01V difference or less. Good luck with the build. Thanks for the response. I typically charge to a ...
by garolittle
Oct 18 2019 1:05pm
Forum: Battery Technology
Topic: Charging and Balancing Questions for LG HG2 pack (14S/20P)
Replies: 10
Views: 398

Charging and Balancing Questions for LG HG2 pack (14S/20P)

Hello. I am using a 14S/20P pack of LG HG2 cells (“18650 lithium ion”) for my prototype electric go kart. What is a safe charging rate for a 20P configuration? I typically charge at 15-20 amps (CCCV) What is a normal “Minimum Voltage per cell”. I have an Orion JR. BMS that is set for 2.9V minimum bu...
by garolittle
Sep 26 2019 8:45pm
Forum: Battery Technology
Topic: Battery options for electric kart
Replies: 29
Views: 749

Re: Battery options for electric kart

Upperfoot wrote:
Sep 25 2019 2:02am

I will be using the Orion JR bms on the pack, and using an Eltek charger alongside it (they both communicate together via CAN)

Very nice! :thumb:
by garolittle
Sep 26 2019 5:51am
Forum: Battery Technology
Topic: Battery options for electric kart
Replies: 29
Views: 749

Re: Battery options for electric kart

Hillhater wrote:
Sep 26 2019 5:43am
garolittle wrote:
Sep 25 2019 7:54pm
We use two separate 14S/20P modules of LG HG2 cells ("18650") connected in series for 51.8Vs nominal.
So is that 28S when connected ?....and 104 v ?
My apologies. I intended to say that it was two modules of 7S/20 P connected in series
by garolittle
Sep 25 2019 7:54pm
Forum: Battery Technology
Topic: Battery options for electric kart
Replies: 29
Views: 749

Re: Battery options for electric kart

We use two separate 14S/20P modules of LG HG2 cells ("18650") connected in series for 51.8Vs nominal. Paired with an AC-9 Alternating Current motor and a Curtis 1236SE controller, this makes for a fun ride. Check it out.... https://www.facebook.com/VenomKarts/
by garolittle
Sep 13 2019 1:36pm
Forum: Large EV General Discussion
Topic: Help me decide: Motor/Charge Controller for 55-MPH Go Kart (PICS)
Replies: 22
Views: 3109

Re: Help me decide: Motor/Charge Controller for 55-MPH Go Kart (PICS)

Wow this is an older topic. I actually did something very similar with a manco go kart. I went with a Motenergy ME1004 Motor, paired with an Alltrax SR48400 controller with Chevy Volt battery modules. I was able to find a high output balancing bms from AliExpress. I was able to purchase most of the...
by garolittle
Sep 02 2019 8:08pm
Forum: Large EV General Discussion
Topic: Go Kart Update
Replies: 74
Views: 7343

Re: Go Kart Update

Great video! Your kart gets better each time I see pictures or videos.