I have been trying to charge some NCR18650 batteries removed from a “new” laptop battery pack. These measured ~1.9V initially.
I am using an Accucel 6 charger, and when I charge @ 1.0 amps, it charges for awhile, but then I am getting “VOL SELECT ERR”, which stops the charging.
I’ve noted that if I bump the charge rate up, say to 1.4 amps, I don’t get this error, and I can eventually charge the batteries to ~4.2V.
My understanding is that that error is because the charger thinks that I’ve selected the wrong type of battery, but it is set correctly, to “LiPo”, 3.7V, so does anyone know why setting the 1.0 amp charge rate would cause that error?
Just a guess, the higher charge rate gives the battery a higher voltage while charging so the charger thinks everything is fine.
With the lower charge rate the voltage on the battery is not as high so the charger thinks something is wrong. Its looking for a normal depleted lipo or li-ion cell voltage. 1.9v would not be normal. Does it still give you this error after the battery voltage reads 3v at rest or so?
So, in other words, since the batteries “look” bad to the charger, since they’re in their new/storage voltage, the Accucel gets that error?
I think it still does get the “VOL SELECT ERR” when the battery starts out with voltage > 3.0V, but I’ll have to confirm that, and will post back here on this thread when I’ve had a chance to test (currently juggling several batteries and chargers). I just started charging a battery that was a 3.89V now, @ 1.0 amps, so let’s see if it gets the “VOL SELECT ERR”?
BTW, so if it DOES turn out that that’s what was causing the error, then, it seems like, with a new battery that is at 1.9V, you wouldn’t be able to charge it with the Accucel “normally” at the “recommended” current of 1.0 amps?
Seems like a kind of “catch-22” :)…
In other words, you would have to kind of “jump-start” such a battery to above 3.0V before using the Accucel to charge the battery @ 1.0 amps.
- One way of apparently doing that “jump-start” is to use the Accucel charging @ 1.6 amps until the battery voltage is > 3.00V.
- Another way seems to be to stick the battery into a charger that doesn’t check the starting voltage, to get the battery to > 3.00V (I have an el-cheapo 1-battery charger, that came with a light, that apparently doesn’t care if the battery voltage starts at 1.9V).
Does that sound right?
Jim
P.S. Accucel still charging that battery that started at 3.89V. No “VOL SELECT ERR” so far :)…
Charging about 10+ minutes so far, @1.0 amps, 4.12V (according to the Accucel.
I’m waiting for the current to start dropping, which I think happens as it gets closer to 4.20V (i.e., going from constant current => constant voltage).
You could also change the charger to nimh, setting it up as two cells watching the voltage as it charges. It should only take a few minutes to bring the cell up to around 3v. Then switch back to lipo and it should charge as normal. The charger is always looking for what it thinks is the correct voltage (low or high) for the cell type you select. If it doesn’t see what it thinks is correct you will get a error. Try disconnecting one lead from the battery while the charger is charging, it will throw a error instantly.
I’ll try the disconnect suggestion in a bit, as it’s at 4.20V now, so I want to let it finish.
I’ll also try the Nimh suggestion, but later. BTW, though, what was confusing wasn’t so much that it was throwing AN error, but that it was throwing that particular (VOL SELECT ERR) error.
This is the first time that I’ve experienced charging “new” batteries that are at the 1.9V/storage voltage, and on thing that I’m learning is that the rules are different vs. charging previously used batteries. Good experience, but a bit painful :)…
P.S. Just noticed that the Accucel has now started dropping the charge current from original 1.0 amps to (now) 0.8 amps. Voltage is currently staying at 4.20V, so I think the charger is now in the CV mode.
I read through your other thread. A normal depleted li-ion should be at around 3.4v when measured at rest (does depend on battery make) and discharge current. 1.9v is not normal, that is considered over discharged. I did see where someone suggested that was fine with a factory new uncharged cell. I have never heard of that before. Waiting to see if that gets backed up. The proper storage (shipped) voltage is considered by many to be around 3.8v or so. That’s the voltage that most batteries that you buy from say fasttech will read when you get them to your door. Member HKJ battery voltage to remaining capacity estimate guide. Battery charge percent
Look down near the bottom of the page. That’s the normal voltages the charger is looking for with some voltage + or - tolerances for li-ions. I don’t remember the actual low voltage in the lipo setting that the charger will happily charge from, but I think its around 2.5v.
first if the laptop battery is new and not charging it is defective and you should call the laptop maker to get a replacement.
due to hazmat requirements you may be instructed just to dispose of the defective battery locally as it is not safe to transport.
that being said
when ever i go to my local scrap yard to cash in metals sometimes there are lithium tool batteries in the bin so i picked up 2 recently and they both was dead at a few milli volts so when i try to salvage them i run the charger in the nicad mode at the really slow charge of 0.01a witch is the lowest setting.
by charging initally at that rate it helps make the charging safer.
probably charging at 1 amp would be safe but i am extra safe since charging is when most fires can happen (remember them hoverboard scooters in the news) there was no safety devices.
1.9v is not storage > that is over discharged. Not quite nasty bad, but pretty damn bad. I’m kind of with ryansoh3 unless you REALLY want to have these batteries and understand the risks of damaged goods.
Storage is around 3.7-3.8v for long term. For short term anything from 3.2-4.0v is OK.
The behavior from the AC-6 is normal. It is telling you the battery is too depleted and is not safe.
You can override this with a short low amp NiXX charge. Watch it the whole time and pull it off when it gets somewhat above 3.0v and resume normal li-on charging. IMO if this does not work IMMEDIATELY you have a crap battery only suitable for discharge and the garbage.
The voltage reading you see on the screen is kind of a mash of battery+charger. It is not the battery voltage. The higher the charge rate, the higher this # will be. That’s why you were able to ‘fool’ the charger with the higher charge rate.
When it gets down to 0.1A charge the voltage is pretty accurate.