Lipo - Is it beyond help??

[adon30]

I have a saddle pack of Muchmore 5000 35C lipos. They are 6 months old, I did buy them 2nd hand but they had only had a couple of runs at the time. So in all they have now had about 50 to 60 run and charge cycles over the time I have had them.
They have always been balanced after charging at 5A and they have always been stored at 65% TCS or slightly higher if thats how they finished after a race (I felt no need to discharge if they were at say 67% TCS).

Now these cells have always shown a small amount of 'bulging'. Not a massive explosion but enough to notice that they do not sit flat. They have been run in a 4WD with a 5.5T motor (although nothing on the speedo was turned up or needed to be!).
I have been playing with settings on the ESC with the PC and used these batteries (from storage) to power the esc. After these I accidently left the power leads connected for a few days.
Luckily I was racing last weekend so noticed my mistake and put the cells on charge ready for the meeting. Due to someone else on the forum having balance issues I happened to check the cells during charging and noticed they were 0.1V out towards the end of the cycle. It doesn't sound much but they are usually 0.002V difference.
After these I checked each cell individually as 1S and brought the suspect cell up to the correct voltage and balance to within 0.002V.
I ran them again this weekend (2 and a half cycles) and again the balancing went to 0.05V out after a run.
When I got them home I tried to just balance them up but there was a big difference again. I storage charged them individually and one cell was around the 67% TCS point and the other was only at 42% TCS. Again I bought the suspect cell back up and it took an extra 600mah+ of charge to get it to the same level as the other and then I balanced them again to 0.002V.
So I thought that may be it and they would stay like that. However next day thought I would check them again and they were out of balance. Checked them individually and the suspect cell was down to 47% without even being connected. Recharged them again as before and checked again the next day and its in the 40%'s again.

I think I've included all the information there.... So is this cell completely FUBAR? Anything that can be done to resurrect it? If not, what do I do with the suspect cell and what to do with the other 1S cell?

My other cells a pack of Muchmore 5200 45C have always been excellent. No bulging and always balanced nicely (they are only 6 months old).
My charger is the Hyperion EOS 0720i NET3

[mark christopher]

bulging means fooked.....

[adon30]

By bulging I would say about a 1mm deflection in the case which it has had for a while.
I have also noticed since last summer that I could only get about 98% capacity into the cells so maybe it has had a problem for a while and leaving it connected just pushed it over the edge.

[MattW]

Ultimately, they are on the way out, not much you can do.