So I’ve torn open 4 old stock new laptop packs so far. Sony, 2 Samsung, and a Sanyo. All the cells charge fine and hold to 4.16v –4.18v after a few hours. So do I let them sit a month now to see if they are ok? I also picked up some new cells! They are fancy button top things I don’t need to solder a button on! Ultrafire 3000mAh red/black with the 3-4 black bars on one end. They are dropping to 4.02 to 4.10 after half a day out of the charger. Initial charge to 4.11 to 4.14 is all. The Ultrafires came bundled with 3 SK98 sets I bought with light/charger/cells. I’m charging on a Nitecore i4 v2 guy that seems to be decent. Questions are:
What is the lowest voltage after a few hours out of the charger that is acceptable? For voltage drop after they are removed from the charger is like wait a week and if below something a decent test? What should my something lowest after a week be?
So far my laptop packs are kicking the butts of the new Ultrafires. I’ll ask about storing them later. Put them in 4 SK98’s and take them down to 3V is what I’m looking at now…LOL I’ve got a lot of cells now. As far as what I’ve seen the new 3000 Ultrafires are what I’d toss out. But that doesn’t make sense?
I want a hobby charger bad. I’ve been looking at them. But I don’t want to have to build battery holders and all that for one. Spending big bucks and then having to hack on it to make it do it’s intended purpose doesn’t seem right. My Lacross BC700 will do nice reporting on AA capacity. So far I’m waiting on Review: Opus BT-C3100 ("dreamcharger!") to come out. It looks like the first real charger for 18650. Actually, it looks just like a Lacrosse BC700 but for 18650.
I never thought about them being damaged. They are new. hmmmm And the laptop packs seem to be best. The new Ultrafires seem iffy. I have so many cells now, many recovered from laptop cells, some new. I’m kinda just wanting a benchmark to use to get rid of say the bottom 10% of them.
You can use any resistors along the lines of 3-10 Ohm. The formula compensates for the variables and should result in the same internal resistance regardless of the resistors used.
I know you said you will ask about storing them later. In case you forget, I would like to tell you now that Li-ion cells do not like to be stored for any length of time fully charged. They will degrade (loose capacity) much more quickly. Now that you have lots of cells , I doubt you can keep them all in use. 3.7V is a good level to have your cells at if you don’t plan on using them for a long time.
easy to do that.toss the whateverfires.
what you spent on them could have bought a REAL imax b6 which is ok for a budget unit.
on second thought hang on to them so we can see how bad they are when you invest in said charger.
, I doubt you can keep them all in use. 3.7V is a good level to have your cells at if you don’t plan on using them for a long time.