My son’s old Compaq/HP laptop has been sitting in the garage for the last year and I finally brought it in to use as a backup. The battery pack hasn’t had much capacity for years and it recently stopped being recognized by the OS as installed. This will be my first laptop pack I bought new and am now recycling.
Boy was I excited. Until I realized that the battery pack completes the bottom and even is needed to keep it balanced on the table or CPU fan. Out comes the dremel and razor knife. scored along the seams and then VERY carefully started removing a corner.
Pulled out a section at the connection side of the battery - but away from the connector. Whew! right over a plastic spacer between the PC board and the cells. Continued scoring along the seams with the goal to leave 3 sides in place so the the case would still support the weight of the laptop and hands on the keyboard.
As I was pulling and prying I found the HP label covered some very thin side walls which were spaced out like a rail fence to hold the cells inside. All I had to do was remove the sticky label and carefully use wire cutters to cut the plastic (and each individual wire lead from the board to the cells). The corner side cut was also useful since I needed to fold one side over to get the cells up and out.
Inside were 8 green Panasonic CGR18650As. Another first: there were also 4 plastic cells that look like they can be wired to act as a dummy.
As is often the case, cells in pairs usually are very close in voltage (I try to keep them labeled as pairs - 2 @ 3.83v, 2 @ 3.82v, 2 @ 3.67v, 1 @ 0.23v, & 1 @ 0.00v.) So 6 very nice cells (assuming capacity isn’t totally shot) & the 4 spacers. The 2 obvious duds will go to the recycling bin. I won’t even try charging them.
My son also gave me a Dell pack that I’ll try to trade at a local PC shop. It has LGs inside. The shop has a contract with Dell for recycling, sometimes I can swap for a larger or nicer pack that way and I’m hoping I can get a replacement for the Compaq laptop free or cheap that way.
Haven’t bought any so far . . keep asking and looking around for used and not working laptop and tool packs. If you get those, plan on doing a few so that you can toss the bad ones - pack I did today was 6 possibly OK and 2 for recycling. Still have to see if the 6 will hold voltage and have decent capacity.
Math on the linked pack:
10.8v / 3.6v (nominal, sometimes they use 3.7) = 3 series
LOL, me too! That was after they were taken apart, measured and cleaned up. Nice pile of trash (+ the 2 recycled cells) built up getting to that point.
I have a buddy that installs security systems for a large internet carrier. He gave me two rechargeable (new unused) packs. Inside were 18650’s. these calls have no markings.
I am planning to use these with a P60 that is .8-4.2v.
You fellas foresee any issues?
There might be markings on the bare cells under the wrappers, but you’ll want to be sure to reinsulate if you pull any off.
You’ll want to check the voltage as you use it . . take some starting and timed measurements on the different modes so that you can catch them as they get down to around 3.15v (to give you some breathing room in case it drops further).
With different batteries, the curve may be different. Also, with some the drop increases fairly quickly, so don’t expect a linear drop in voltage.
Your biggest concern is accidentally leaving or turning the light on and not catching it.
