More RC LiPo to repair:
PDF donated three 6s 5Ah Turnigy packs to me for the cost of shipping that all have a dead cell (same one in each pack, which seems wierd: the one just above the most negative one.). They arrived Friday, same time as the chargers from Dirtdad/Comcycle, but I haven't gotten around to posting about them until now.
An odd bit of story to them is that even though he packed them VERY well and completely labelled them as they should be, the UPS store employee that took the package in from him decided it would be better to hide all that scary hazardous materials labelling by repacking it into a larger box with a bit of packing around the smaller original box.
Anyhow, some pics of the stuff. Hachi has taken over the chief inspector's position vacancy left by Bonnie:
The UPS Store's packing around the smaller box, inside their box, which I guess was adequate:
PDF's excellent packing, in two separate layers of packs:
Then the individually-packed and wrapped packs isnide that:
Note that two are wrapped in painter's masking tape to prevent any shorts because they are both partly disassembled and/or unwrapped, while the third hadn't yet been worked on.
Next, I did a quick cell-check at the balance taps with first the crappy MaxPro, which doesn't even try to read actual pack voltage nor does it bother to display any cell that is "below" (on the more negative side of) any dead cell.
The first one only reads one cell, at 3.70V.
Next one (still shrink wrapped) only reads three cells, and the Maxpro thinks it's only 3.70V pack voltage because the first cell is that, and then for some reason it can't read the next cell (it has problems liek that a lot; each time I use it I am reminded of why Methods didn't want it anymore
and sent it to me as a donation to play with as I felt like it.
Same problem reading the next pack, though this time it gets a red LED lighting up; presumably because one cell it can read is actually below 3.6V (or maybe 3.5V)? It still thinks pack voltage is only 3.75V.
Next I checked them with a Battery Medic donated by Mdd0127. At least it can read all the cells and the actual pack voltage, even when there is a dead or missing cell!
The first pack it can't even power up from.
The next pack it powers up ok and shows me one dead cell, and the rest in the 3.67-3.7V region.
The third pack has the same dead cell position, and two lower cells than the rest, which are 3.7-3.74V. The low cells are 3.43 and 3.52V.
Opening up the tape I find the reason for the first pack's readings:
The disassembly on it includes disconnecting most fo the balance wires, and one cell is completely removed already (inserted in the pack with the tabs wisely taped off to prevent shorts).
I havent opend the tape on the third pack yet, but the most positive end cell (3.52V) is puffed up; not as clear in the pic as it is viewing it in person.
Voltage readings on the cells in the first pack:
For now they're stored in this Freecycled old 50-cal ammo can, with the lid left caught on the latch but not fully closed:
Will try to get to them to at least remove the bad cells and puffy ones Tue or Wed on my next days off.