Rebuild a laptop battery pack

In this episode I show how to rebuild a Lithium battery pack for a laptop.

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[FennecTECH]

"ultrafire" probally not the best brand name for lithium batteries"

[Sefilenginar]

One tip: Adhesive copper tape does wonders - adheres very well and you don't need to heat up any part of the cell, and they are very thin meaning they're good for confined spaces (like these laptop batteries) where soldering adds unwanted thickness. Less messy too, and no need for extra wires or anything. I used them for two separate batteries that I refurbished a while back and they work seamlessly.

[IIGrayfoxII]

I got 4 of those 6, 000 mAh of those ultra fire batteries for an LED torch
The capacities were tested with a Foxnovo F4-S
136mAh
272mAh
409mAh
351mAh

[saintsainty]

Hello guys, this 2024 September 24. I used to have that laptop many years ago, i bought it as a used laptop. I was happy to own an apple laptop, and learning how ox work, since i am a windows user. My battery was bad, though as a computer technician, i was able to rebuild it, and go about three hour from it. Was mainly using it to watch movies. Those days was fun. The battery, you bought the capacitance or power was low.. mine i later used the battery pack to build and laptop battery backup. I was just tired of mac, because of the software i had was on windows pc. It was really fun building battery and pc in those days. Thanks man.

[BroadcastChannel]

When getting lithium cells make sure to get the tagged ones if you are going to be soldering them. Applying a soldering iron directly to the cell is very bad as too much heat is transferred in to the cell which can damage the cell or even trigger a thermal runaway. Permanent connections made directly to the cells should only be done with a tag / impulse welder to minimise heating to the cell.

[brandonlehman]

The old intro is quite nostalgic, can't believe the growth this channel has had!

[JakeJoris]

"ultrafire" batteries have capacity from 50mah to 400mah.

[Yeen]

To be fair, my only and major concern about buying cheap batteries from China is that they may explode after a certain period of time.

[wateringcan]

For anyone reading this, you need a class D fire extinguisher in order to stop a lipo fire. Regular ABC extinguishers won't work, and they can actually spread the fire. I couldn't find the extinguisher in the video online anymore, but I found similar ones from the same manufacturer, and I am nearly certain they wouldn't be effective against a lipo fire.

Sorry for being critical, especially on such an old video, but I had to mention it since it's a matter of fire safety.

[wonton]

To get an old laptop working that needed a bios update, which requires at least a 20% battery charge as well as mains supply. With the laptop battery removed, I connected my old 9v battery drill battery directly onto the laptops battery pins for the +- -, did the bios update, which fixed the battery charging problem and as a bonus it fixed the RAM issue that had more than 1/2 the RAM reserved. Job done.

[rsn]

Great tutorial.  I've done this a lot with older laptops and it works great, but there are a few things to watch out for.

1) Don't buy cheap batteries from eBay.  Buy them NEW from a reputable source.
2) Buy the batteries *with the tabs*.  YES!  You can buy them brand new with the tabs welded on them.  If you try to solder to these batteries directly like that you can damage them and even cause them to catch fire or explode.  In properly made 18650 batteries, that top button tab that you soldered to is not actually connected directly into the battery.  It would be connected through a PTC+CID device (which sometimes is that top tab) that can fail at high temperatures or over-volt/over-current conditions.  So soldering directly to it can actually kill the battery or even destroy the protection device making the battery very dangerous.
3) This simple method will not work with most newer laptop batteries.  Most newer laptop batteries require you to reset or reprogram the charge controller.  Some even lock you out once you remove the old batteries and so you need to replace _and then_ reprogram the charge controller chip to make it work properly.  So if you're really determined it can be done, but you can save yourself the time and money and just get a new one...

[robertnoble]

Soldering directly to the cells is NOT a good idea. To be safe, you should buy cells that have solder tabs welded to each end. Then make solder connections near the end of the tabs away from the cell.

[paijoaoxxi]

I love your videos! They're always so creative and different from other Tech channels out there. I don't see them making iMac G3 Cathouses or replacing Laptop Battery Packs. Even older videos from 2012-2014 are still relevant and cool. Good Job! (I do like other Tech channels. I just enjoy your creativity!)

[no-damn-alias]

Would've been interesting to see the internal resistance of the old cells and what their capacity still is

[THEtechknight]

You actually got really lucky that it took off and worked. I have seen more often than not, the controller's EEPROM needs to be re-virginized and have all the "battery dead" flags reset. Dell batteries are notorious for that, same with IBM.

[AlanNg]

Straight to the point addressing the pros and cons of these El Cheapo batteries.

[Valveman]

Thanks for the video!

I have a Toshiba T1100 Plus that was given to me. Of course, the old NiCad battery pack was dead. I went to a battery store and obtained some new cells, rated at 5000mah instead of the original 4000mah. All I can say is that the run time is incredible! I used that laptop as my school laptop in college, and I used it all the time. I would get about 10 hours of run time on it, and only had to recharge it once a week.

Keep in mind that I was using this computer at school just a few years ago, not back in the 90's or something. It turned out to be the most reliable computer I have ever owned. I got a lot of looks with that old dinosaur :)

[supercrazymario]

I’m going to rebuild a PowerBook G4 Titanium battery with 8 genuine 3500mah 18650 cells from Panasonic and this video sure helped me!

[codebeat]

Notice (and warning): This will only work for dumb/dolt battery packs (for example the battery pack of the IBM 2141). If there is a circuit board included inside the battery package, for example to charge the batteries balanced and/or a chip (IC) to report the health of the battery, a 'smart' battery (not only just a simple current protection IC), this might not work and could be dangerous.

The problem is the health data stored/recorded inside the IC. It is not calibrated like you noticed, well, it actually is, however with old batteries in mind. Some IC's use also a charge counter to determine the health status (lifetime) of the whole battery, after X charges it needs to be replaced and/or it will use a modified charge/operating scheme. This is for safety but also to sell new batteries.

If you replace the batteries with new ones, the IC 'thinks' these batteries are still the old ones and charges the new batteries like the old ones (for example at higher current). Result: The batteries will last a little longer however not as long as should (like you noticed - no evidence the batteries are of bad quality) and the batteries could be damaged earlier, can get very hot, start to leak or even explode. You are warned, do not underestimate batteries of this type or caliber.

You can only do this when you can reset the chip (must support an extended battery protocol) however only a few support this. In this example it is Apple, I am sure that is not possible. Don't waste your time and money to such revive projects, it won't last very long and could be (very) dangerous. Also solder the joints is a pretty bad practice but that's another story.

No blame at all, hopes it helps by experience, by being informative to avoid unnecessary dangerous situations to other people.

[Kotesu]

There might be a secondary issue with the short run time of your batteries: internal resistance and brownout. As your computer pulls current from a battery, the chemical reaction that occurs can - if they're old or poorly constructed - not be able to react fast enough to push more electrons through. This manifests as a dip in voltage until the action that's pulling extra current ends. The problem is that most battery monitors use voltage to determine the state of the charge, so your laptop suddenly freaks out and thinks the battery is dead.

Putting cells in parallel does two things: 1) they offer greater capacity, but equally as important 2) increases the maximum current output of the pack. Given the cheap Chinese cells, the electrolyte inside might be contaminated or more likely that the electrodes have less surface and reactive area.