The vintage batteries thread- Q&A

[newob]

Are there any good places to find old NiCD's these days other than ebay? Can they still be bought new I wonder?

[slotcarrod]

eBay mostly! You find them in Buy Sell once in a while, once you gain access!

[vegasjetta]

Wait, are these old batteries still usable? I am stupid when it comes to this stuff. I have 6 sets of these sitting in my garage. Can they be revived?
If so, does anyone want them? I won't use them for anything, would you guys into the hardcore vintage stuff want them for display purposes, even if they are dead?

Side one


Side two

[slotcarrod]

I would keep them! You never know when the bug hits you to restore a car, and now you don't have period correct batteries to put in them.

[Charlie don't surf]

Those Orion cells aren't easy to find- especially those red/yellow 1400's if you just have to get rid of them Lmk-
Otherwise you might want to keep them and see where you go with this vintage hobby-

[xo1tech]

It was pretty common practice (back in the day), to use resistors to bring the cell voltage down close to zero to remove the memory effect that all nickel cadmium batteries exhibit.

The only problem I ever had with this was the fact that no two nicads would ever have the exact nominal voltage. That made the matching process necessary to maximize the average voltage a pack would supply.

I had assembled 2 - 1400 mah, 5 cell, PTI SUPER GOLD Saddle Packs to run in series in an RC10L. I forgot and left a 10 watt, 30 ohm, ceramic resistor on the (series) pack for a week.

The next time I went to charge them my charger recognized the fact that the polarity was reversed in the pack. I traced the charge leads back to the output ports on the charger, verified that the leads were hooked up correctly, and started the charge process again with no change in the result.

I took my volt meter and checked each individual cell (still connected in series), paying close attention to ensure I had the positive voltmeter lead on the positive end of the battery as I watched the polarity indicator on the voltmeter. 5 of the 10 cells had indeed reversed polarity.

Even though the individual cells had been closely matched by PTI, and again by me before I assembled them, there were still variations in the nominal voltage between the individual cells.

By leaving the resistor on the assembled pack for an extended period of time I had driven the highest voltage cells in the pack to zero voltage and the ones with lower nominal voltage had gone to the negative side of zero (reversing their polarity).

Given the PTI’s were $95.00 for 6 cells (un-assembled), and as new as they were, I was determined to find a way to save them (if at all possible).

With the cells still connected in series, I connected the same 30 ohm resistor to only one of the reversed cells and monitored the cell voltage until it came back up to zero volts.

I disconnected the resistor and quickly zapped the cell with 5 short bursts of 50 amps of current at 5v. The cell would immediately reverse again.

I finally enlisted another pair of hands and a friend’s help. After bringing the cell back up to zero again, I had him to control the connection of the resistor to the cell and remove it milliseconds AFTER I had started the zap process. We repeated this process for the other 4 and they all came back to the positive side of zero and then took a charge.

All 5 cells were damaged by the reversal, but after several cycles, the pack (as a whole) came back to approx. 97 percent of its original capacity.