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thaiceman

New member
Joined
Jun 8, 2021
Messages
3
I hate you all, this is your fault & now I am going to be playing with the forbidden AA till I figure out something to do with the ones I harvest.
Ive got another opus, an 8 bay charger, shrink wrap, insulators, & my 3d printer is making a holder as I type this.

 

OffGridInTheCity

Active member
Joined
Dec 15, 2018
Messages
2,032
Welcome. The founders of this site + some others got me addicted - and now I'm here pay it forward. Whether the payments are saintly or devilish is TBD. If you want to avoid battery addiction leave this site now and never return!
 

floydR

Member
Joined
Aug 23, 2017
Messages
1,443
:)Welcome enjoy you need more tools. at the very least an Internal resistance meter, spot welder, maybe three or 4 multimeters, autobody trim tools( hard plastic to pry open battery cases), kapton tape, silicone tape and or plain eleictrical tape, heat shrink for wires multiple sizes, heat gun, thermal camera or Infra red thermometer
Later floyd
 

thaiceman

New member
Joined
Jun 8, 2021
Messages
3
:)Welcome enjoy you need more tools. at the very least an Internal resistance meter, spot welder, maybe three or 4 multimeters, autobody trim tools( hard plastic to pry open battery cases), kapton tape, silicone tape and or plain eleictrical tape, heat shrink for wires multiple sizes, heat gun, thermal camera or Infra red thermometer
Later floyd
I've got tools unfortunately one can never have enough tools there is always something else you can get, buy, build to make live easier.
 

MBF Dan

Member
Joined
May 14, 2021
Messages
35
Welcome from another newbie. I will say definitely get a way to test the internal resistance of the cells. It will save you some serious head scratching when that charger doesn't want to charge cells. I put it aside and only use the zonflare chargers now. They allow me to check the resistance when I load the cells. As soon as I popped the questionable cells into that charger and checked I all the sudden knew why the other charger didn't seem to like them. Would have saved a ton of time if I could have checked the resistance first.
Oh and you will need to keep the cell database on here open at all times I keep opening cells and jumping in there to see what goodies I just got...
 

floydR

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Joined
Aug 23, 2017
Messages
1,443
I've got tools unfortunately one can never have enough tools there is always something else you can get, buy, build to make live easier.
I see. All but the internal resistance meter I was only half serious about needing. I use an YR1030+. Read upon wolf's posts he has done extensive testing and comparison of the various IR meters. His build thread is a good read. Looks like you have a good supply of tools.

later floyd
 

thaiceman

New member
Joined
Jun 8, 2021
Messages
3
I see. All but the internal resistance meter I was only half serious about needing. I use an YR1030+. Read upon wolf's posts he has done extensive testing and comparison of the various IR meters. His build thread is a good read. Looks like you have a good supply of tools.

later floyd
Any reason not to use the internal resistance reading from the Opus at least for the time being?.. If anything I can always use my fluke and some resistors if I need an hyper accurate reading & believe me I understand the value of a good meter I keep one for car batteries around so I can test UPS batteries.

Conveniently I run a computer repair shop here in my town so I have a fairly endless supply of 18650's of questionable quality lol
 

Korishan

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Joined
Jan 7, 2017
Messages
6,835
Greetings @thaiceman. Always welcome and room for more victims, I mean friends.

Nice looking shop you got there. Plenty of space to work with. Maybe another thing you can add to your list is a bucket with water in it in case of a cell that starts to short out (rare, but does happen) when removing from packs. The water helps to cool it down before it goes thermal ;)

As a side note, when posting images, could you use the built in images uploader instead of an outside one. We have no issues with storage space ;) You can just drag drop the images into the editor to make it easier.
 

floydR

Member
Joined
Aug 23, 2017
Messages
1,443
Any reason not to use the internal resistance reading from the Opus at least for the time being?
You can try the opus built in tester"quick test" but it is very inaccurate often high on the same cell that tested low before. alot has to do with the contacts placing a pencil behind the the bottom contact helps. Not too sure about how much it helps. Different cell chemistries test differently too if you don't have a datasheet for a particular cell you can see if there is one here in the cell database. sometimes the IR is given in the datasheet other times it isn't or it is buried.

later floyd
 

daromer

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Oct 8, 2016
Messages
5,662
thaice: There is no reason to use the internal reading at all! Because its off, it can vary easily 100mOhm.
Its better to buy proper one or notuse it in my world :) Having faulty readings is almost worse than not having any :)
 

B8rez 2g4

Member
Joined
Jun 21, 2021
Messages
38
thaice: There is no reason to use the internal reading at all! Because its off, it can vary easily 100mOhm.
Its better to ..... notuse it in my world :) Having faulty readings is almost worse than not having any :)

Can you elaborate on this.
If cells test fine. Charge and Discharge fine ...
Testing for internal resistance is not necessary ?
 

MBF Dan

Member
Joined
May 14, 2021
Messages
35
Can you elaborate on this.
If cells test fine. Charge and Discharge fine ...
Testing for internal resistance is not necessary ?
I think the point was simply that the cheap charger testers are not accurate enough to be useful. I have seen this myself I was going to toss a cell for testing > 600 on internal resistance only to have the cell slip out of my finger and the holder reseat to read below 100. Such a test is meaningless as you don't know if you are seeing an issue with the cell or the tool
 

daromer

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Oct 8, 2016
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As MBF Dan said.. readings that are off are worse than no readings. IR readings persue is not bad to have. In fact they are crucial in some or many builds. But if you do a high current test like 1A or above you also get an indication of that the IR is decent to cope with that current. But you should not go above that later on.

Those cheap testers can vary between 50-150mOhm easily. If you need IR reading or building smaller pack use a proper 4 wire tester instead. Wold will most likely chime in because he run Ir testing first and then capacity. I only run capacity on my wall. Or did... :p
 

Wolf

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Sep 25, 2018
Messages
1,693
Wold will most likely chime in because he run Ir testing first and then capacity. I only run capacity on my wall. Or did...
The name is Wolf as in 🐺 😛

Can you elaborate on this.
If cells test fine. Charge and Discharge fine ...
Testing for internal resistance is not necessary ?
Several different opinions on this.
My technique is very simple. I take an IR and V reading of every cell that is not physically damaged as a first touch with my RC3563 and record it in a spread sheet.
I compare the IR to my IR cheat sheet. https://drive.google.com/file/d/1n6DU0VC7Yjksz2ah90VUcpw6SW6kFqQt/view?usp=sharing
If the cell does not pass the IR limits no matter what the voltage, it goes to the recycle bin.
I then test the cells.
I have used just about every commercially available tester but I do like the OPUS and SKYRC because they can be set to C/D/C at 1A. For the OPUS to work properly at 1A it does require a fan upgrade.
I now use The Megacell Charger pretty much exclusively and for the 1 or 2 occasional test cells I use the SKYRC.
With this method heaters and underperforming cells are virtually eliminated and your harvest will be rather successful.

Otherwise you can just insert cells into a charger/analyzer OPUS or SKYRC, remember its pretty critical to C/D/C at 1A to flush out heaters and low performer's if you don't want to check IR.

I personally would not build a battery without knowing the IR of each individual cell but that's me.
I like to be sure my packs are as safe as possible.

Wolf
 

daromer

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Oct 8, 2016
Messages
5,662
Sorry! Fat fingers. Its of course Wolf :)
 

italianuser

Member
Joined
Feb 25, 2020
Messages
478
:D That typo made me laugh!

Yes, for IR testing first choice to start with could be what our best suggest, I bought a YR1030 and I'm really satisfied with it. My chargers' IR measurement (Liitokala 500) isn't realiable.

P.S.
Ah, for @Wolf 's IR cheat-sheet I have some info on Samsung 22P which is missing. I'm going through final selection phase before building the pack and tested quite a few used cells at 90% (from datasheet here they are nominal 2150mAh, initial IR <=35mOhm).
- 140 cells, measured capacity after C-D-C cycle in 2000-2099 range: n.41 cells IR between 27-29mOhm; n.99 cells between 30-36mOhm;
- 30 cells, measured capacity after C-D-C cycle in 2100-2199 range: n.25 cells IR between 24-29mOhm; n.5 cells between 30-32mOhm;
- 13 cells, measured capacity after C-D-C cycle in 2200-2219 range: all cells between 25-26mOhm.
 
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