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Good Afternoon
just joined having used the cell database for the last 3 days!
I'm new to this and need to get educated.
I bought a couple of cheap Amazon work lights containing two badly spelled skins "UtlraFlle BCR 18650 3.7v 4200mAh" or something and was suspicious - anyway on one thing led to another and I ended up replacing the cells after some research here for LG MJ1's from a reputable source.
Then tested the USB charging function to see it they were actually safe to use, leave unattended and store in the camping gear safely!
So, here I am having had a baptism of virtual cell flre (lol) looking at how I can apply these fantastic energy sources into my life....

I've been given a couple of crates of laptop batteries, mostly with 18650 cells that I need to investigate and quantify.
70+ odd batteries look new but out of shelf life or from obsolete HP , Compaq laptops and Covid is helping reduce storage and shelf space.
I'm not looking to sell any or reveal my legitimate source either! Its a one off.

I'm thinking of a Powerfloor in the van rather than a wall, but open to suggestions and views of course.
I doubt it will be on a par with some of the projects I've seen on here but its a start and one that'll be super useful.

Say hello and I hope to be part of this + community.

Sounds like you have a plan, but you need a charger/tester that does discharge testing, I use an Opus 3400 others use the Opus 3100.There are a several other testers. Consistency in testing is the key. use a test that charges to 4.2v then discharges. LiitoKala is another tester used here. use one brand of tester. There are other good brands of testers. the iCharger series of testers are good too.
Also a good internal resistance checker to help determine if a cell is good.RC3563, YR1035 are two good 4 wire IR testers. Lower reading is better.
Welcome to the LAA worldwide chapter 24/7
later floyd
Activ8 likes this post
Thanks floydr.
I have an XTAR Li-Ion charger but will buy an OPUS as suggested.
Whats the benefit in a discharge test/er? I'll read up too.
I've carefully broken up 6 batteries and the 36 individual cells (SONY, LG & SAMSUNG) so far have all charged to 4.2v.
Should I store them discharged while I work through the haul and the planning phases?
Sleeves we're all good and I didn't inflict any damage with my breakout technique!
Are the laptop cell electronics useful for any purpose?
Apologies for the questions!
Depending on which Xtar li ion charger it may be capable of testing 18650's. The XTAR DRAGON VP4 Plus Charger can do much more than an OPUS. if you have all the accessories for XTAR DRAGON VP4 Plus Charger I believe it has a 4 wire IR tester.
I use OPUS 3400 because there is a seller of the OPUS 3400 in the same city as me.
The testing has more to do with consistency  test the cells the same way every time with the same brand of charger than to tell the exact mAh of a cell.
I store cells at the voltage they come out of the battery pack. I may precharge the cells prior to using the tester. Shortens the charge protion of the charge test(opus). charge- discharge-charge would be a complete test cycle.
I haven't found a use for the electronics doesn't mean there isn't one.
Questions are welcome

later floyd
Activ8 likes this post
Thanks floydr.
Just ordered the XTAR Dragon VP4 Plus, with all the extras - it will compliment my VC4.
Right - better crack on with some reading and get these cells ready for testing.
Thanks again.
There's several flowcharts suggesting the best ways to test cells.
Generally starting with IR* is a good place to start.
* internal resistance, measured with an AC IR meter eg YR1030 & other similar 4 wire units (not a regular multimeter)

I was looking for this link earlier:
This thread has suggestions on better ways to test cells for powerwall use...
Activ8 likes this post
Running off solar, DIY & electronics fan :-)
Thanks Redpacket.
The flow chart diagrams have provided this newbie with a great process to follow.
I've checked a few battery packs (bought the respective laptops and AC chargers cheap) as a first "test" then topped the cells up using the XTAR VC4 to 4.2v.
Some failed the laptop test but the cells charged up to 4.2v on the XTAR.
Albeit its just a first charge, all the cells have come within a few % of their rated capacities.
I'll restart the process when the Dragon Unit turns up.

I now need a temp storage system for the cells.

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