Search found 52 matches

by jimbo69ny
May 25 2018 6:21pm
Forum: E-Vehicles General Discussion
Topic: How do I know if I need a battery isolator?
Replies: 3
Views: 626

Re: How do I know if I need a battery isolator?

They actually dont have to be the same. This has been tested by Jack Ricard from EVTV. My numbers might not be exact but roughly, he connected 1 Tesla 85kwh pack that was 90% charged to another Tesla 85kwh pack that was 30%. The packs shut down. It was too much current. So he got them a little close...
by jimbo69ny
Apr 26 2018 10:41pm
Forum: Battery Technology
Topic: Tesla module charging to full/degradation
Replies: 10
Views: 405

Re: Tesla module charging to full/degradation

With all due respect, I dont think that is it at all. I dont have the specs in front of me but the Rav4 Tesla motor isnt nearly as demanding as the Model S and X motors. The big important difference is that the Rav TMS only operates when the car is on and in "ready" mode or when charging. All of the...
by jimbo69ny
Apr 26 2018 5:20pm
Forum: Battery Technology
Topic: Tesla module charging to full/degradation
Replies: 10
Views: 405

Re: Tesla module charging to full/degradation

Oh good to know. I have a 2014 Rav4 EV. The car is made by Tesla and has a Tesla 41 kwh battery pack. I have noticed degradation after only 3.5 years. The peak voltage I have seen is 376 volts. The pack is a 92s40p. 4.1 volts x 92 cells = 377.2 volts so that makes sense. I was wondering why my pack ...
by jimbo69ny
Apr 26 2018 12:49pm
Forum: Battery Technology
Topic: Tesla module charging to full/degradation
Replies: 10
Views: 405

Re: Tesla module charging to full/degradation

oh ok. I was wrong. Thank you!
by jimbo69ny
Apr 25 2018 9:44pm
Forum: Battery Technology
Topic: Tesla module charging to full/degradation
Replies: 10
Views: 405

Tesla module charging to full/degradation

I have been thinking about this for a while now and I haven't read anything about it. This might be a stupid question but I need to know. It is no secret that 18650 cells/Tesla modules degrade with time. I assume that something inside the cars software knows how much degradation is there and how hig...
by jimbo69ny
Mar 19 2018 10:02pm
Forum: E-Vehicles General Discussion
Topic: Need thin, non conductive, fire retardent sheets. Mica?
Replies: 2
Views: 383

Need thin, non conductive, fire retardent sheets. Mica?

Hello, I am looking for thin sheets that are non conductive and fire retardant for my battery box. I've heard and seen that Tesla uses mica sheets in their battery box. I looked up prices on ebay and amazon and the stuff is expensive! Do you have any other recommendations? I need approximately 8 she...
by jimbo69ny
Feb 18 2018 7:06am
Forum: Battery Technology
Topic: 18650 questions - How does internal resistance relate to voltage?
Replies: 11
Views: 554

Re: 18650 questions - How does internal resistance relate to voltage?

Wow! Thank you Sunder!! You answered all of my questions in beautiful detail! Thank you so much!
by jimbo69ny
Feb 17 2018 8:15pm
Forum: Battery Technology
Topic: 18650 questions - How does internal resistance relate to voltage?
Replies: 11
Views: 554

Re: 18650 questions - How does internal resistance relate to voltage?

So measuring the resistance is creating a circuit? I guess technically maybe you are right because you are creating a path but never in any of my years of schooling did anyone claim measuring resistance was completing a circuit. Can you send me links on these threads? If using my DMM isnt the correc...
by jimbo69ny
Feb 17 2018 6:43pm
Forum: Battery Technology
Topic: 18650 questions - How does internal resistance relate to voltage?
Replies: 11
Views: 554

Re: 18650 questions - How does internal resistance relate to voltage?

Again, this doesn't answer any questions. lol

I know you cant measure the resistance of a live circuit. I was measuring the resistance of a single cell. Was I not clear? Let me know if I need to reword my questions.
by jimbo69ny
Feb 17 2018 12:40pm
Forum: Battery Technology
Topic: 18650 questions - How does internal resistance relate to voltage?
Replies: 11
Views: 554

Re: 18650 questions - How does internal resistance relate to voltage?

I appreciate that you took the time to comment but that isn’t my question. I already knew that.

My questions are about the relation of voltage to resistance and about amp hours.

If anyone else has answers I am very curious to know what you think.
by jimbo69ny
Feb 17 2018 10:58am
Forum: Battery Technology
Topic: 18650 questions - How does internal resistance relate to voltage?
Replies: 11
Views: 554

18650 questions - How does internal resistance relate to voltage?

Hello Everyone, I recently picked up a bunch of laptop batteries and I had a few questions. How does internal resistance relate to voltage? Does it? I want to test to see what happens when you put a low resistance cell and a higher resistance cell, in parallel, in a circuit. Lots of people have opin...
by jimbo69ny
Feb 15 2018 11:49pm
Forum: Items Wanted
Topic: Anyone want to send me free dead 18650 cells?
Replies: 24
Views: 1195

Re: Anyone want to send me free dead 18650 cells?

OK - I'm surprised none of the senior forum members have yet to chime in on this one but it can't go unsaid any longer. This is what we call a teachable moment. To be clear - this is no personal attack - so please don't take it as such. Any sarcasm (of which there will be much) is solely intended t...
by jimbo69ny
Feb 15 2018 6:31pm
Forum: Battery Technology
Topic: Lithium Li-Ion 18650 capacity meter "Gas gauge"
Replies: 14
Views: 1458

Re: Lithium Li-Ion 18650 capacity meter "Gas gauge"

Thats good news because I just bought one. :)

Should be here in 4 months
by jimbo69ny
Feb 15 2018 6:30pm
Forum: Battery Technology
Topic: Best laptop battery tester? Opus?
Replies: 2
Views: 252

Re: Best laptop battery tester? Opus?

I actually already owned this one so I dug it out of storage and used it to charge some 18650s. It worked great!

https://www.amazon.com/gp/product/B0109 ... UTF8&psc=1
by jimbo69ny
Feb 15 2018 10:25am
Forum: Items Wanted
Topic: Anyone want to send me free dead 18650 cells?
Replies: 24
Views: 1195

Re: Anyone want to send me free dead 18650 cells?

Wow, I am amazed at the overreaction of your post. I wasnt asking anyone to do anything illegal so dont get your panties in a bunch. People mail lithium ion cells all the time. As far as I know no one has gone to jail for this. I have no idea why you are so upset. As for "storing my cells in a woode...
by jimbo69ny
Feb 15 2018 9:55am
Forum: Battery Technology
Topic: C Rating of 18650 cells in my project? Advice please.
Replies: 14
Views: 518

Re: C Rating of 18650 cells in my project? Advice please.

Great points. I havent looked into pricing or any other BMS' yet. $1000 to cover a $14,000 battery doesnt seem that bad. Cheaper is always better though. I will look at that once I get closer to needing the BMS. I have another thread on this already but I am currently looking into the issues of runn...
by jimbo69ny
Feb 15 2018 9:30am
Forum: Battery Technology
Topic: C Rating of 18650 cells in my project? Advice please.
Replies: 14
Views: 518

Re: C Rating of 18650 cells in my project? Advice please.

Wow thats a good deal. Do you have any info on who to contact to buy them? Someone reliable hopefully? As for the rest of it, I dont know, that seems like a lot. I think my system will be pretty simple. 92s31p in parallel with the existing 92s48p Tesla pack. Because it will be in parallel the onboar...
by jimbo69ny
Feb 14 2018 8:33pm
Forum: Items Wanted
Topic: Anyone want to send me free dead 18650 cells?
Replies: 24
Views: 1195

Re: Anyone want to send me free dead 18650 cells?

Me too! Thanks everyone!
by jimbo69ny
Feb 14 2018 6:59pm
Forum: Items Wanted
Topic: Anyone want to send me free dead 18650 cells?
Replies: 24
Views: 1195

Re: Anyone want to send me free dead 18650 cells?

I am testing 6 of them now. Of those, some were close to dead, some were around 2.6 volts. I am charging each of them now. So far seems like they are maxing out at 3.99 volts. IDK what that means. Also, I thought resistance of them would be different. But pretty much everyone I tested is around 800 ...
by jimbo69ny
Feb 14 2018 4:41pm
Forum: Items Wanted
Topic: Anyone want to send me free dead 18650 cells?
Replies: 24
Views: 1195

Re: Anyone want to send me free dead 18650 cells?

JACKPOT! I went to 2 local computer repair places and scored about 30 laptop batteries. I just took them apart and I have about 200!

Image
by jimbo69ny
Feb 14 2018 10:25am
Forum: Battery Technology
Topic: Best laptop battery tester? Opus?
Replies: 2
Views: 252

Best laptop battery tester? Opus?

I searched but I didnt find an answer.

What tester/charger do you guys like? I have heard mixed reviews of the Opus. Also I have read that the Opus doesn't read internal resistance which is a feature that I want.

Any suggestions would be appreciated.
by jimbo69ny
Feb 14 2018 10:17am
Forum: Battery Technology
Topic: The 3500mAh heavyweight division: Sanyo NCR18650GA vs Panasonic NCR18650GA vs LG MJ1 vs Samsung INR18650-35E
Replies: 29
Views: 5588

Re: The 3500mAh heavyweight division: Sanyo NCR18650GA vs Panasonic NCR18650GA vs LG MJ1 vs Samsung INR18650-35E

Beautiful test! Good job! Have you considered retesting? I am wondering if you tried different cells if the brands would perform equally to the result of this test. Hopefully the cells are consistent though, just wondering. Also, if you still have these exact cells, I wonder how they have changed wi...
by jimbo69ny
Feb 14 2018 10:04am
Forum: Battery Technology
Topic: Lithium Li-Ion 18650 capacity meter "Gas gauge"
Replies: 14
Views: 1458

Re: Lithium Li-Ion 18650 capacity meter "Gas gauge"

Has anyone tried one of these before? https://www.ebay.com/itm/400V-300A-DC-Digital-Voltage-Meter-Ammeter-Voltmeter-Capacity-Coulomb-Counter/352245023429?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649 They come in all different variants. They seem nice for the money but I worry that they...