Battery pack refurbishing with new Li-Ion cells? Opening the battery?

"I can't answer all of your questions - but let's start with a few infos.

the ""round"" formfactor of the battery tells me that there are ""18650"" cells inside the battery - you can use something like the ""SANYO 18650 3.6V 2.6Ah/2600mAh Cell"" for that, but they are expensive.

you could build a 5.2Ah (6 cell) or 7.8Ah (9 cell) battery with them.

the ""conspiracy theory"" about the charging counter came up on many devices, mostly MacBooks have those funny problems ;-)

in fact, those dead batteries are not ok, i disassembled a few MacBook batteries and tested the li-po cells - there was always one cell that had a problem while the others were fine!

since those batteries are only using simple charging electronics - they orienting the whole wharging process on the weakest link. they don't have real balancer (as used in the R/C scene) - so if one cell is bad - the whole pack is ""dead"" - replacing the bad cell with a known good one will revive those batteries (thats why many ""freaks"" are buying dead MacBook batteries on ebay - buy 6 dead ones for 10 bucks or less and sell 5 working ones for togehter ~250$)

i think you won't need the exact video for your battery - here's one that shows the changing process in common: CLICK here"

Well I read the same wave-offs regarding my old IBM laptop battery (Ni-my). With having spent $120 on a replacement I figured why not? I had to use a sharp knife to split the seams. It may be necessary to use a heavier tool like a hammer or vice-grip (use your imagination). Carefully split the seams open all round, taking care not to damage the internals. Note that the seams may not for whatever reason follow a straight line. Prise the halves apart taking care not to break them. The battery of cells should be removable at this point. Now for the delay in progress. You probably have no clue as to what to ask for. Carefully measure the dimensions of one of the cells. Draw a rough sketch of the cell upon which to record the information. If you're lucky there may be a manufacturer's part number on it. If not, you'll have to reference these measurements with a distributor's literature or catalogue to get the right item(s). Sometimes due to progress you'll find a significant improvement in capacity over the old cells, which can translate into longer run times. As they say, size is important. This all has to fit back into the old casing. Once the parts have been ordered and received, you may carefully solder the new battery together. I hope you've been honest with yourself about your soldering skills. A couple clip-on heat sinks may come in handy here. Before you begin, refer back to the old battery. There may be one or more protective devices installed amongst the cells. After taking care to record their position on paper (again, you may want to make a drawing) clip them out so as to preserve them from yet another exposure to soldering heat. You're going to re-use these. Using the drawings and the old article as a guide, assemble the new cells so as to fit them into the old casing. It may be helpful to tape them together. Scotch Magic Tape worked for me. The newly assemble replacement should fit back into the old case. The plastic "clips" on the case may not hold well now, or may have been damaged upon removal. You may use adhesive to hold it all together. With an eye to possibly (ugh) having to do this again I opted for a wrap or two of the aforementioned Scotch tape. It would be easily removable, doesn't add too much thickness, and was quite adequate for a battery that resides inside an easily accessible battery bay.

"It doesn't appear that the specific 'ask' has been answered, so for completeness...

Many products such as battery packs with 'no serviceable parts inside' (as opposed to no user serviceable parts) are not even glued together, they use a sonic heat process to melt the plastic at the edges in a permanent 'weld' process. They do this primarily for speed and cost, but I think they also appreciate the side benefit that assemblies are impossible to disassemble without leaving visible marks. Visible marks indemnify the manufacturer in case of disaster or injury during use following modification.

How to disassemble? Depending on the product and your skill, use your own imagination. I would probably use a dremel tool with a thin blade and attempt to follow plastic seams. Obviously care is needed to avoid cutting through the battery cells' metal container. It would be best to cut at an angle or perhaps halfway across a seam at one angle and a different angle for the other half so that the angles help with realignment upon reassembly. For reassembly, use glue and fill the saw gap. Hot glue would possible work well. File or sand any aberrations.

Another respondent described (did not necessarily recommend) the practice of replacing the single bad cell in a series-pack. So, it should be noted that li-on batteries have limits on the number of charge-discharge cycles that they are capable of; they do wear out. If not replacing all cells (regardless of whether they presently work) one would be limiting the life of the repair to the remaining life of the not-new cells. A person's time and effort may be worth more than the cost of replacing all batteries in one shot.

While you're at it, build a back-up pack..."

"Check out this video for opening a DELL battery pack:

http://www.laptop-junction.com/toast/con..."

"Hi,

I have my HP Pavilion laptop battery - that I replaced less than a year ago - almost dead. I would like to change its cells to a better / higher longevity cells. My dead battery has 3x2 Samsung ICR18650-26H cells. What can I exchange these cells with ? I'm a bit lost when it comes to mAh , capacity and A... I don't wanna use the same cells as I really would like to upgrade my battery. These Samsung cells came with the battery I bought over the internet to replace my original dead battery about a year ago, unfortunately I don't know what cells that original HP battery had since I don't have it anymore. The original battery used to last up to 4 hours...which I was never able to achieve with this bad replacement battery. any advice please on a new cells choice ? Thanks,"