[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
(ET) Status update, bad but maybe not destroyed.
So I started checking cells starting with the front pack.
The first two cells were low, but not empty. I added about 30-40ml of
water in them, then checked the rest. Most were low-ish, so I topped
them off with between 15 and 20ml of water. They are now all at the
midpoint of the V regardless of charge, I need to get *something* here
that is at least stable.
Of the two cells, one came up to .6v (good) and the other was at zero. I
checked resistance of the cells, in one direction they are zero but in
the other they are around 22 ohms. That could be a positive indication.
With that done I checked the charge voltage on an open pack (40v), then
connected the interconnect in the front pack and fired up the charger.
Voltage on the pack came up to 42v, the second cell went up to 1.4 and
after a minute the first cell started to climb from 0 to .5, .8, 1.1,
and stabilized at 1.4. Good.
Shut down the charger and checked the voltages on both cells. They held
at around 1.3 or so, also good.
With that I'm putting the front pack on a 1 hour charge to let it come
up to speed. There is enough water that it should keep the pack from
running away and I'll keep an eye on it.
For the rear pack most cells were fine. The one at .8 volts was low on
water but once again I filled all cells to the midpoint then hooked up a
3a supply to half the pack and set the vooltage limit to 21.5 and the
current limit to 3a. Will let that charge through this evening, then
charge up the other side once it drops to 0a.
On the back pack the forward most cells may have a chance. All so far
have had the caps come off with a strong vacuum pop (showing they had
vented) but still took water. So pack 2 might be intact, just needing a
solid charge.
Pack 3 (the rear most that was involved with the short) is *NOT* happy.
Of the first five cells, four of them read 0 ohms in either direction
(bad) and more importantly the water level was not coming up. They may
have been breached and melted a hole in the battery case, I'll check
when I pull them. The second set of five all took water so the damage
may be limited, may not. I'll work on those later. First step is going
to be fixing pack 1, then pack 2, then hooking in pack 4, then seeing
what we got that works in pack 3. Could be only 5-15 cells are blown,
could be more, we shall see.
C