Batteries can't just look at very external parameters
Samsung 26F 2600mAH is a very high-quality electrical core, good product consistency, high cycle life
The quality of LG M26 is average
Sanyo UR18650FM 2600mAH is more expensive, close to the cost price of 3 U.S. dollars
But it's still used by many companies
Then the retail market of foreign trade is very confusing, many fakes, you will detect discrimination? That's a low price, a dime a share. Many domestic electric cores are used for rewap fake vtc5,25r etc
Or fake 25R uses 22P, fake HG2 uses MG1 or MH1,VTC5A use vtc5
I guess you got such a cheap samsung26f
There are two possible, fake 26F or used 26F, positive and negative will leave traces of welding,disassembled from the battery pack
I think the product is good. That shop was entitling itself as “Colaier Direct Sales Store” some time ago. They may have some old stock to get rid of, protected cells may be somewhat unappealing to people… but in any case I am pretty sure they avoid declaring shipping of li-ion cells to get super-cheap shipping costs for these packages (more than a month to reach home).
I am just curious how much does the seller charge to ship to you in Spain? US $54.74 to Australia for 4 pieces of batteries is just crazy. Even if you are buying 10 pieces of batteries, this shipping charge is still too expensive.
If there is savings going with cheaper shipping option, I am more than happy to wait 4-6 weeks. The “Free” shipping from suppliers like GB and BG typically takes 4-6 weeks to get to me in Australia anyway.
OK
I have four unprotected GA cells.
Two were discharged to 0V by a flashlight with extremely high parasitic drain and were at that 0V for a full week.
All four charge normal
All four hold a charge normal
None get hot during charge
All four have an internal resistance between 20 and 40
Still I don’t use them and I can’t tell them apart now.
I know there are dentrides in two.
So now that is seems normal to use cells like this please experts tell me how I can sniff out the two dangerous cells.
I can’t use any without seriously endangering my family and material possessions.
The Miller, with regards to discerning the supposedly damaged cells one of the easiests ways would be to capacity test all of them on an analyzing charger. The cells which suffered a one week long 0V “break” should show a perceptible reduction in capacity.
Another way, for example, would be to charge-balance all 4 cells and set them in series, proceeding to discharge them with a constant light load of some sort while monitoring cell voltages. One way to make this unattended is equipping the cells with equal 1S BMS circuits. Damaged cells will go down earlier and their final resting voltages after weakest cell cut-off should be noticeably lower.
Yes oh sorry I did not stick a piece of paper with mAh on them.
Did test them and all four were close, it was not like two were lower.
They also took about the same time
This is a test of discharge and charge
So let’s see what Trisky can say to help me sniff out the two cells that are not safe to use but charge, discharge and hold charge like good celks, it is a little too quiet from the professional selling cells for this should be minimal knowhow before selling old rusted damaged cells on a forum with 20+K members with various skill levels.
It can’t be expected to rig up some BMS continuous discharge series setup, lol I could probably buy a lot of brand we cells for those parts.
On topic advice: I believe Trisky needs to find the most “reasonable” shipping costs for these deals to become more attractive.
I haven't asked for a shipping quote yet, but I can show you how paying just north of $1 per cell is already a deal killer in some cases: if I were to, let's say, build a high capacity battery pack, would I choose the FST 2200mAh (which is probably an effective 2100mAh cell) over the Samsung 32E, a proven, high voltage, 3100mAh class high quality cell? The FST 18650-2200mAh price, in this example, would be $1.80 ($0.80 + $1), while the Samsung 32E would be $2.60 ($1.60 + $1). In this case I'd choose the 32E without hesitation.
FastTech quotes me an average of $0.60 per cell via Sweden Post to Spain. That would be reasonable.