Search found 45 matches

by jimbo69ny
Feb 18, 2018 7:06 am
Forum: Battery Technology
Topic: 18650 questions - How does internal resistance relate to voltage?
Replies: 11
Views: 140

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 8:15 pm
Forum: Battery Technology
Topic: 18650 questions - How does internal resistance relate to voltage?
Replies: 11
Views: 140

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 6:43 pm
Forum: Battery Technology
Topic: 18650 questions - How does internal resistance relate to voltage?
Replies: 11
Views: 140

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 12:40 pm
Forum: Battery Technology
Topic: 18650 questions - How does internal resistance relate to voltage?
Replies: 11
Views: 140

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 10:58 am
Forum: Battery Technology
Topic: 18650 questions - How does internal resistance relate to voltage?
Replies: 11
Views: 140

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 11:49 pm
Forum: Items Wanted
Topic: Anyone want to send me free dead 18650 cells?
Replies: 24
Views: 319

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 6:31 pm
Forum: Battery Technology
Topic: Lithium Li-Ion 18650 capacity meter "Gas gauge"
Replies: 14
Views: 768

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 6:30 pm
Forum: Battery Technology
Topic: Best laptop battery tester? Opus?
Replies: 2
Views: 90

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 10:25 am
Forum: Items Wanted
Topic: Anyone want to send me free dead 18650 cells?
Replies: 24
Views: 319

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 9:55 am
Forum: Battery Technology
Topic: C Rating of 18650 cells in my project? Advice please.
Replies: 14
Views: 190

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 9:30 am
Forum: Battery Technology
Topic: C Rating of 18650 cells in my project? Advice please.
Replies: 14
Views: 190

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 8:33 pm
Forum: Items Wanted
Topic: Anyone want to send me free dead 18650 cells?
Replies: 24
Views: 319

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

Me too! Thanks everyone!
by jimbo69ny
Feb 14, 2018 6:59 pm
Forum: Items Wanted
Topic: Anyone want to send me free dead 18650 cells?
Replies: 24
Views: 319

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 4:41 pm
Forum: Items Wanted
Topic: Anyone want to send me free dead 18650 cells?
Replies: 24
Views: 319

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 10:25 am
Forum: Battery Technology
Topic: Best laptop battery tester? Opus?
Replies: 2
Views: 90

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 10:17 am
Forum: Battery Technology
Topic: The 3500mAh heavyweight division: Sanyo NCR18650GA vs Panasonic NCR18650GA vs LG MJ1 vs Samsung INR18650-35E
Replies: 25
Views: 1412

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 10:04 am
Forum: Battery Technology
Topic: Lithium Li-Ion 18650 capacity meter "Gas gauge"
Replies: 14
Views: 768

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...
by jimbo69ny
Feb 14, 2018 9:56 am
Forum: Battery Technology
Topic: C Rating of 18650 cells in my project? Advice please.
Replies: 14
Views: 190

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

I have been speaking with Liion Wholesale and he recommended the LG MJ1 cells over the Panasonic NCR18650B cells. Panasonic are around 3340 mah nominal at 6.7 amps peak and the LG's are 3400 mah nominal at 10 amps peak. He quoted me a price of only $3.80 per LG MJ1 cell! Panasonics were $1 more! Wha...
by jimbo69ny
Feb 13, 2018 10:46 am
Forum: E-Vehicles General Discussion
Topic: How do I know if I need a battery isolator?
Replies: 0
Views: 105

How do I know if I need a battery isolator?

Hey guys! I am working on a project to add a battery pack to my 2014 Rav4 EV to extend range. The OEM battery is made by Tesla and uses 2600 mah 18650 cells in a 92s48p configuration. My plan is to add 3400 mah 18650 cells in a second battery pack. My pack will be 92s31p. I thought I could simply ru...
by jimbo69ny
Feb 13, 2018 10:37 am
Forum: Items Wanted
Topic: Anyone want to send me free dead 18650 cells?
Replies: 24
Views: 319

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

The box is eventually going to a welder so he can copy it and make me one out of aluminum with the same dimensions.
by jimbo69ny
Feb 12, 2018 9:42 pm
Forum: Items Wanted
Topic: Anyone want to send me free dead 18650 cells?
Replies: 24
Views: 319

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

Yeah I’ll some! I hope it won’t be too much to ship. I bought 20 off eBay for $13 shipped. He sent them wrapped in a bag in a priority mail envelope. No stickers or signage.
by jimbo69ny
Feb 12, 2018 9:17 pm
Forum: Items Wanted
Topic: Anyone want to send me free dead 18650 cells?
Replies: 24
Views: 319

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

Freeville ny 13868. Just outside Ithaca.
by jimbo69ny
Feb 12, 2018 9:02 pm
Forum: General Discussion
Topic: Building a really big pack, could use some advice.
Replies: 12
Views: 179

Re: Building a really big pack, could use some advice.

A new potential issue was just brought to my attention. My OEM Tesla pack uses 2600 mah 18650 cells. It’s 92s48p. I want to add a 3400 mah 18650 cells. My pack would be 92s31p and it would be in parallel to the OEM pack. I haven’t considered resistance yet and someone told me that the 3400 mah cells...