OK ... I have a few 3S and 4S packs that have a dud cell ... but the other cells seem to hold and provide good power ... I agree that it's only a matter if time before they go west also .... but ....
There are times when a model is poorly designed / made that CoG is a problem and often requires weight up front.
Given that a 4S pack of similar capacity weighs significantly more than a similar 3S pack ... if the 4S is dud on one cell ... (I know you lose 1/4 mAh) ... maybe it can be used in that 3S model that needs nose weight.
Similarly the 3S with a dud cell in a 2S model.
I've looked at the packs with idea to cut out the dud cell ... but the foil tabs and soldering is welded or Hard soldered - not Soft soldered. I'm a bit reluctant to play about with cells and trust them to stay connected etc.
How many people modify or use such packs ? So far I use them for bench testing ... but thinking to use in less demanding models.
ditto fh,i can't stand batts that have defects. the one's i hate the most is a broken red or black lead. i have tried to reheat existing solder on the wire but it never holds.
i no longer pop/burn packs to the open air and pollute my neighbors air. i use a 3 prong garden rake to poke a hole,wait for the smoke to start and plop it in a small bucket of water to boil away. after a few minutes it threat is done. i leave it in the bucket till i get around to tossing it.
having only flown electrics I've smoked enough batteries to no longer need to see the deadly smoke.
this reminds me to pop 2 batts in the storage cabinet that just aren't safe anymore.
narrow is the place to land...wide is the space to crash....choose the narrow way!
Yep, it would only be safe to do this if you bypassed the bad cell by re-soldering the output wires, or removed the cell completely. Otherwise you are still passing full current through the damaged cell which is likely to end badly. To be honest really not worth the hassle.
I guess I haven't run into those "hard soldered" or "fuse soldered" cells. A lot of guys in my club fly 5,6,7,8,10 cell packs. When they lose a cell or two, the packs come to me (I'm the club scrounge). I use WD40 and an old business card to separate the cells. Next I snip off the metal connector tabs on the bad cells. I use those salvaged tabs to make new connections. I still have a hammer head iron from NiCad days and use it when resoldering. I like to have a lot of heat that can be applied quickly before the cell heats up.