Ok I’ve done a laptop pull on a new but unused Asus battery. Date inside was 2010 February.
Voltage
2 × 2.19
4 × 2.29
2 × 2.40
Any concerns or just start cautiously charging?
I have experimented with old (not unused) laptop cells as low as .72V and though they were only about half of their original capacity left, they were still fine.
On the first charge, just don’t leave them unattended. Physically touch them every now and then for sudden increase in temperature. With any sudden, unusual increase, stop it immediately and time to put them away.
If they are from an old but unused batt pack, chances are they are still fine. I notice major laptop manufacturers always use cells from major brands anyway.
They are Samsung ICR 4.3 2800. I’m charging them with a 4.2 charger now. They are a bit warm to touch but not hot. Is there a dangerous temperature they shouldn’t reach?
I’ve got them charging on a metal surface covered by a ceramic pot presently.
New cells that have never been charged and have self-discharged down to a low voltage aren't the same thing as cells that have been run down to a low voltage under load. New laptop packs and the new cells inside them literally have never been charged, their starting voltage (usually 3.65v or so) is what they have just from assembling the new internal layers of the cell in the factory. I'm sure there's some automated diagnostic checks done when building the packs, but they aren't charged & discharged ever until the end user gets them.
They seem to be fine temperature wise. Sitting comfortably at 30-32 degrees C after 2 hour of charging. I don’t have the tools to measure Ri but I guess these are quality cells anyway.
Been charging for 4 hours now at 1a, but voltage is still only 4.12. Batteries are cool.
Continue is ok? Is that normal for the first time?
I ended up with 60 (yes, sixty) of those 28As a while back, they were likely the same age and condition, though I think the starting voltages were a little higher, and they have all performed like new.
Knowing one data point, that it's at 4.12v right now, isn't much to go on. Is the charger is still running at the full 1A with the voltage that high? If you don't want to keep charging, take them out, check the voltage after 10 minutes or so, then check them again in 12-24 hours. If it doesn't change much, they're fine and just need more time in the charger.
I can’t confirm the current no, haven’t gathered the tools to test that yet. I’ll let it rest at and test the voltage tomorrow. cheers.
Took like 12 hrs (until bed time) to charge at 500mA from 2.x to 4.02. Resumed charging the next day for about 2+ hours until charging stopped with the final reading of 4.2. The battery got only lukewarm throughout and at charge ending, the battery was cool if I recall. Think your battery is “normal”.
find any good NOS laptop deals lately?