I do stuff similar to that all the time, usually trying to find a slightly bigger one that fits the exact same package.
do you have all the MM specs of the size of everything?
do you know the max rate of discharge for the replacment?
MacBook? with a few 1300ma cells?
are there 6 of these cell items?
is it parellel series?
FInd:
basically i spend hours making sure that the size will fit , when you have a tight fit like a OEM pack item.
i try to discover the specs on the original, and basically understand the load specs of the device. then get the specs on the battery i intend to use for replacement. it has to be able to do the job completly not just look similar.
Pre-Test:
Then do a full analisis of the external connections (of the original pack) for testing, you want to do the same testing
now externally to the pack that you will do before shoving it into a expencive device. so before it comes apart, you have to learn everything you can about what your seeing on the Outside.
Test New cells:
then test each of the new cell items for actual capacity, insuring that they will make a usefull team of cells. ohhh to bad you got a dud , and you didnt buy a spare , now you gotta wait a week to get fully maching cell items. :-(
Set cells to low same levels:
have every cell set to lower voltages and the same as the others. Discharge all the cells to a logical low, for working with the pack.
check check check:
observe all insulation points, find the safety stuff, like thermal fuses and whatever they use, not just the position of all of it. WHY is that there, ask yourself why every piece of foam or insulating tape, or cardboard or plastic or electronics is where it is, generally there is a reason.
Remove the old cells , without destroying tiny curcuit stuff on protection and info board. but using enough heat to not have the cells tabs getting to hot (from moving to slow).
if i couldnt Un-solder it because of crappy tools/equiptment , then i sure as heck cant get it back safely.
check all connection points, shape trim and align everything, with Freaking HOT batteries, yup the work is always with live exisiting power the whole time, dont forget it, or it will remind you
Tin the ends of the batts, which can be pure heck sometimes, again if you cant do it, then you ruined it by getting it to hot.
check where everything that can go wrong will, and try and prevent that, while stuffing the new cell items in.
then hope the chip that does the protection info doesnt require some sort of "reset" to get it working, or mabey you just screwed up and you can go onto the next one , cause that one will never work again
Test Test Test: now that you believe you got it back together physically, you have to test all external aspects of it electrically, BEFORE stuffing it onto anything. check the voltages, try and charge it OFF of the expencive devices, know that it is working as the original would, then say 3 prayers to appropriate gods, and stick it on the device.
is it worth it, dang straight, is it a pain, depends how much space or how intuitive thier assembly is.
