May I ask where you got it for $32? Opus C3100 v2.2 ?
Tutorial: Laptop Battery Pack 18650 Extraction
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markr6
Flashaholic
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Gearbest, about a month ago. It may have went up a bit, but I think it's still around $35-40. Good value! I'd gladly pay $50 for this charger.
wrcsixeight
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Hello. A few pages back, back in December '14, I replaced my 9 cell laptop battery with another sub 25$ one from Amazon, and harvested the cells. One was bad, the rest have been put into use in flashlights and a portable USB power supply. Their remaining capacity was not impressive compared to Ncr18650b's.
The replacement battery pack just got weak enough that I ordered the same battery pack as it was good a good enough value for the amount of cycles i got from it.
So another Cell harvesting. At this point I've only opened the casing. I was hoping to identify the cell manufacturer and original capacity, but no luck on google.
GOB18650-14FO4-20c-3. 7v are the only markings. They are a light turquoise color. I don't have my Nippers handy to separate the cells, nor my voltmeter to check, but will report back.
Anybody know anything about who made the cells, or its original capacity, or is it just China's cheapest and not worthy of discovery?
The replacement battery pack just got weak enough that I ordered the same battery pack as it was good a good enough value for the amount of cycles i got from it.
So another Cell harvesting. At this point I've only opened the casing. I was hoping to identify the cell manufacturer and original capacity, but no luck on google.
GOB18650-14FO4-20c-3. 7v are the only markings. They are a light turquoise color. I don't have my Nippers handy to separate the cells, nor my voltmeter to check, but will report back.
Anybody know anything about who made the cells, or its original capacity, or is it just China's cheapest and not worthy of discovery?
wrcsixeight
Newly Enlightened
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- Nov 10, 2013
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The laptop battery I just harvested, refused to charge above 92%, It would just say '92%, not charging' and stay there no matter how long I was plugged in. Battery life had dropped to about 45 minutes from that point
I was plugged in reading 92%, when I turned laptop off, removed and replaced battery with newest arrival from same vendor, made sure it worked properly, and then cracked open the 92% one.
6 cells measured 4.23 volts
3 cells measured 3.986 volts
I subjected each cell to a one minute test on my Nitecore HC50 on the brightest setting. Was not able to measure voltage during test but measured it quickly after.
In the time it took to remove and test the battery, the voltage had rebounded to 0.1 of where it started and then to within 0.02 a few minutes later.
Not much of a load test, but no battery visibly caused the brightness to fade during that minute. The 3 lower voltage cells had their voltage rebound quickly as I measured, the other 6 to a much lesser degree.
I unwrapped each one, soldered a button onto each one, and rewrapped them all. i bought something like 5 meters of shrink wrap just for one orbitronics cell whose wrapper was torn.
I'm charging the 3 lower voltage cells now.
My previous cell extractions can not fully charge my Samsung s4 mini phone, but the panny ncr3400 Mah cells could do that almost twice.
I am not sure whether the BMS in the battery pack decided to take the 3 cells out of rotation or what, but it did seem like capacity dropped by 1/3 practically overnight. My one minute load test revealed next to nothing, so I will have to see how batteries 4,5 and 6 behave from this point.
My previous harvest had one cell whose voltage dropped from 4.2 to 3.9 overnight, the rest of them held 4.2 for days.
Have more 18650 cells than I can realistically use at this point.
I was plugged in reading 92%, when I turned laptop off, removed and replaced battery with newest arrival from same vendor, made sure it worked properly, and then cracked open the 92% one.
6 cells measured 4.23 volts
3 cells measured 3.986 volts
I subjected each cell to a one minute test on my Nitecore HC50 on the brightest setting. Was not able to measure voltage during test but measured it quickly after.
In the time it took to remove and test the battery, the voltage had rebounded to 0.1 of where it started and then to within 0.02 a few minutes later.
Not much of a load test, but no battery visibly caused the brightness to fade during that minute. The 3 lower voltage cells had their voltage rebound quickly as I measured, the other 6 to a much lesser degree.
I unwrapped each one, soldered a button onto each one, and rewrapped them all. i bought something like 5 meters of shrink wrap just for one orbitronics cell whose wrapper was torn.
I'm charging the 3 lower voltage cells now.
My previous cell extractions can not fully charge my Samsung s4 mini phone, but the panny ncr3400 Mah cells could do that almost twice.
I am not sure whether the BMS in the battery pack decided to take the 3 cells out of rotation or what, but it did seem like capacity dropped by 1/3 practically overnight. My one minute load test revealed next to nothing, so I will have to see how batteries 4,5 and 6 behave from this point.
My previous harvest had one cell whose voltage dropped from 4.2 to 3.9 overnight, the rest of them held 4.2 for days.
Have more 18650 cells than I can realistically use at this point.
SilverFox
Flashaholic
Hello Wrcsixeight,
When a Li-Ion chemistry cell comes off the charger below 4.0 volts, or drops below 4.0 volts 24 hours after charging, the internal chemistry has been used up to the point were the cell has lost around 20% of its initial capacity. At this point the change in internal chemistry properties make it less safe to use and it should be recycled.
If you continue to "play" with the low voltage cells, use caution and watch closely.
Tom
When a Li-Ion chemistry cell comes off the charger below 4.0 volts, or drops below 4.0 volts 24 hours after charging, the internal chemistry has been used up to the point were the cell has lost around 20% of its initial capacity. At this point the change in internal chemistry properties make it less safe to use and it should be recycled.
If you continue to "play" with the low voltage cells, use caution and watch closely.
Tom
wrcsixeight
Newly Enlightened
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Thanks Silverfox.
My plan was to remove any cells which could not maintain voltage after fully charging to 4.2v. Only one cell in my previous harvest failed this test.
The recent harvest, occurred when the laptop itself has charged the battery as much as it could, to 92%. 3 of the cells were the same at 3.986 volts. the other 6 just over 4.2v.
These 3.986v'ers were all charged to 4.2v by my nitecore i4v2 and monitored for excessive heat during, and now will be monitored over the next few days for dropping voltage to see if any need to be recycled.
My imprecise load test revealed no weaknesses on the 3 lower voltage cells. I was kind of thinking the BMS in the cheapo battery pack was at fault rather than a faulty cell, as on my previous extraction, one cell was obviously the culprit, and the other 8 still in use but with not so impressive capacity.
My plan was to remove any cells which could not maintain voltage after fully charging to 4.2v. Only one cell in my previous harvest failed this test.
The recent harvest, occurred when the laptop itself has charged the battery as much as it could, to 92%. 3 of the cells were the same at 3.986 volts. the other 6 just over 4.2v.
These 3.986v'ers were all charged to 4.2v by my nitecore i4v2 and monitored for excessive heat during, and now will be monitored over the next few days for dropping voltage to see if any need to be recycled.
My imprecise load test revealed no weaknesses on the 3 lower voltage cells. I was kind of thinking the BMS in the cheapo battery pack was at fault rather than a faulty cell, as on my previous extraction, one cell was obviously the culprit, and the other 8 still in use but with not so impressive capacity.
wrcsixeight
Newly Enlightened
- Joined
- Nov 10, 2013
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- 116
I have a single cell 18650 USB power supply, and last night used it through a KCX-017 USB power meter to recharge my capacity compromised Samsung S4 mini battery that was in the 20% range.
At 775 mAH, the USB power supply quit with one of my harvested cells in it, one which read 4.23v upon extraction.
I am charging that same cell now with power meter on it, and it has now accepted 1670mAH and is still accepting 0.15amps at 5.18v.
This is the only method I have to measure any cell capacity, and it seems quite inaccurate, or my single cell USB power supply is only ~50% efficient. Sure it is warm, but not that warm.
I expect these harvested cells were 1800mah originally and should at least be able to get my phone to 100% from 20% once, but it came nowhere near that.
My Panny cells can do the job and some more though this same USB source.
Looks like i'd have to carry 2 or 3 of these harvested cells to do the same job as one 3400mAH Panny.
Perhaps I wasted my time and shrink wrap and solder on them if all perform as badly in my usages.
At 775 mAH, the USB power supply quit with one of my harvested cells in it, one which read 4.23v upon extraction.
I am charging that same cell now with power meter on it, and it has now accepted 1670mAH and is still accepting 0.15amps at 5.18v.
This is the only method I have to measure any cell capacity, and it seems quite inaccurate, or my single cell USB power supply is only ~50% efficient. Sure it is warm, but not that warm.
I expect these harvested cells were 1800mah originally and should at least be able to get my phone to 100% from 20% once, but it came nowhere near that.
My Panny cells can do the job and some more though this same USB source.
Looks like i'd have to carry 2 or 3 of these harvested cells to do the same job as one 3400mAH Panny.
Perhaps I wasted my time and shrink wrap and solder on them if all perform as badly in my usages.
Phlogiston
Enlightened
Bear in mind that the mAh reading on a USB power meter is measured at 5V, whereas the cell's rated capacity in mAh is measured at 3.7V. To make proper comparisons, you need to multiply mAh by measurement voltage to get mWh. 1 mAh at 5V is 5mWh, whereas 1 mAh at 3.7V is only 3.7 mWh. That's roughly a 25% difference in energy when going from 5V to 3.7V, or 33% going the other way.
Your USB power bank has to convert voltage upwards (boost) or downwards (buck) when producing or accepting energy, respectively, so it will be subject to this effect.
Every USB power bank I've ever seen gives its mAh capacity rating at cell voltage, i.e. 3.7V.
My rule of thumb for charging a USB power bank is that it will take the same number of mAh at 5V as its cells are rated for at 3.7V. The remaining energy is lost to inefficiencies in the power bank's circuitry and the Li-Ion charging process.
My rule of thumb for using a USB power bank to charge another device is that it will only produce about two thirds of the mAh at 5V that its cells are rated for at 3.7V. In other words, a 12000 mAh power bank will only put about 8000 mAh into your device. The difference is mostly accounted for by voltage boost from 3.7V to 5V, with some additional energy being lost to inefficiencies in the power bank's circuitry.
Using those rules of thumb, the 775 mAh your power bank produced at 5V implies that the cell had about 1150 - 1200 mAh at 3.7V in it, assuming that you have a reasonably efficient power bank.
At reasonable efficencies, I'd predict that the 1670 mAh that you've put into your power bank would allow it to charge another device by about 1100 mAh. I'd be interested to know how well it actually does - and what model of power bank it is - should you have the time to check.
Your USB power bank has to convert voltage upwards (boost) or downwards (buck) when producing or accepting energy, respectively, so it will be subject to this effect.
Every USB power bank I've ever seen gives its mAh capacity rating at cell voltage, i.e. 3.7V.
My rule of thumb for charging a USB power bank is that it will take the same number of mAh at 5V as its cells are rated for at 3.7V. The remaining energy is lost to inefficiencies in the power bank's circuitry and the Li-Ion charging process.
My rule of thumb for using a USB power bank to charge another device is that it will only produce about two thirds of the mAh at 5V that its cells are rated for at 3.7V. In other words, a 12000 mAh power bank will only put about 8000 mAh into your device. The difference is mostly accounted for by voltage boost from 3.7V to 5V, with some additional energy being lost to inefficiencies in the power bank's circuitry.
Using those rules of thumb, the 775 mAh your power bank produced at 5V implies that the cell had about 1150 - 1200 mAh at 3.7V in it, assuming that you have a reasonably efficient power bank.
At reasonable efficencies, I'd predict that the 1670 mAh that you've put into your power bank would allow it to charge another device by about 1100 mAh. I'd be interested to know how well it actually does - and what model of power bank it is - should you have the time to check.
CatcherInTheRye
Newly Enlightened
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- Dec 24, 2016
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- 1
Hey guys I've read a few replies to this but my current electrical tape is too thick. Is this dangerous to have parts of the wrapper shrink wrap be peels or damaged (it's on the size, none are on the ends). What is the proper way to dispose of these? Thanks
Took apart an old laptop battery pack last night and got 6 nice 18650's. Thanks for putting this up!
zorobabel
Newly Enlightened
I took apart an older Dell battery pack and got 6 red batteries coded IL4FK6. I can't find anything on this code. Is silicone RTV ok for insulating the nicks on the wrapping?
Re: Recovering batteries from notebook battery pack
Hello,
Can you help my find the model and specs for this batteries from old laptops?
One is Red Sanyo with green ring and the other is Sony US17670GR.
Thanks!
Hello,
Can you help my find the model and specs for this batteries from old laptops?
One is Red Sanyo with green ring and the other is Sony US17670GR.
Thanks!
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