Manufacturers had improved production techniques that all batteries were now Magically Calibrated or trained at the factory.
![best replacement battery for macbook pro 15 late 2008 best replacement battery for macbook pro 15 late 2008](https://m.media-amazon.com/images/I/21FHSPhw22L._AC_.jpg)
Later we were told this was a waste of time. When the Lithium batteries 1st came out we were instructed to fully "TRAIN" the batteries. I'm recently retired - 40+ years IT & Support. No disrespect meant Kirk - but you are completely wrong ( But what I want to know is does this solve the issue of getting shut off at 20 % so I can use it like before to 5% before it goes to sleep? And do you have any idea why this is? But what's the difference here? They both write RAM to disk so in case of complete power loss your computer would still be able to get out of sleep by pulling your previous session from the disk. I understand that putting it to 25 will store RAM to disk instead of 3 storing to disk while also keeping it in RAM. Can you explain why this option works for you? I'm gonna try it now, but I wonder why having it at 3 (mine was also at 3) would cause the Macbook Pro to do this at 20 - 40 % battery left.
![best replacement battery for macbook pro 15 late 2008 best replacement battery for macbook pro 15 late 2008](https://www.macbatteryshop.com/pic_big_Zoom/a1281-50wh-6.jpg)
It did this with the original battery and the 2 new ones I've just tried. And just like yours, it's also just shutting off (it seems that way) without any warning at around 20 %. I have the same issue as you have! I just installed a new battery received from IFIXIT as a replacement for the previous new one I got because of this problem. What does "allow it to drain overnight" mean? To drain it by using the macbook or to let it drain in a turned off device (which would take way longer then only 1 night)? Is it necessary to reset SMC?.If yes in what step?
BEST REPLACEMENT BATTERY FOR MACBOOK PRO 15 LATE 2008 HOW TO
TL DR: How to correctly calibrate the battery after replacement, step by step guide. Could someone provide a clear step by step guide what to do after replacing the battery. 40% of charge (initial delivered battery charge, 0 cycles) and I have no idea what to do since I'm afraid I could run into the same problems as first time. So now I have a turned off macbook on ca. Charge it again and use it normally" is pretty clear to me since it indicates you are supposed to use the macbook until it shuts down automatically. Does that mean I'm not supposed to turn on the macbook for the first time at all and the battery is going to discharge by itself to 0%? I don't believe the battery can drain to 0% after one night sitting in a turned off macbook, right? The second part of the instructions "then charge it to 100% and drain it again until your MacBook Pro shuts down automatically. For example the first part says "allow it to drain overnight". The calibration instructions aren't entirely clear to me. 57% of charge and I continued discharging the battery by using the macbook and then I thought maybe I'm following the instructions wrongly.
![best replacement battery for macbook pro 15 late 2008 best replacement battery for macbook pro 15 late 2008](https://venturebeat.com/wp-content/uploads/2019/11/sirired.jpg)
Now I installed the 2nd new battery and turned the macbook for the first time on and it showed ca. I explained all of this in detail (including coconut battery screenshots) to the customer service and they send me a new battery saying the one I received was damaged. I tried everything including SMC and PRAM reset but the macbook stopped going into hibernation mode. When I turned on my macbook after the replacement it showed a charge of 59%, then I used the the macbook until it turned off automatically, but the problem was it didn't go to hibernation on about 5% as usually, but it suddenly turned off on about 18% and all work in progress was lost. "Calibrate your battery before using it: allow it to drain overnight, then charge it to 100% and drain it again until your MacBook Pro shuts down automatically. I bought a replacement battery from ifixit and installed it, then I followed the instructions: