Red,

On your website, you state discharging NiCad cells to 1.1V then storing them in the fridge. Will the same work for NiMH cells? I have some packs I will not be using till next year and want to take care of them properly.

Thanx,



Rob

Yes it will be fine for Ni-Mh for the same reasons I state below. It will help sort out cells that have separator deterioration. Here is the statement you are referring to.
"Should I store my batteries charged or discharged?" It doesn't really matter, they will self discharge in a few months stored at room temperature. If you are going to store them in the refrigerator the charge will remain for a lot longer so I would discharge them first to 1.1 volts/cell and them put them away. Good cells will just set there in the discharged condition (the voltage can vary considerably but is usually above 1 volt). In a battery with damaged "worn out" separator in the cells, the cells are apt to short if left in a discharged condition. This is actually good since it is the first indication of a cell that's going bad and it is best to replace the pack. A battery left on trickle charge will seldom short out since it is in the charged condition and any short that tries to develop will be zapped by the charge in the cell. Partial shorts (those having fairly high resistance) can be developing that can cause the cells to self discharge at a higher rate than normal and possibly leave you short in the middle of a flight after you just measured the cell when it came off charge with your ESV and everything looked OK.

If I interpret that properly, when I take the pack out of storage, check the voltage. If the pack (4 cell) still around 4V before charging, then it has probably survived storage without a seperator failure?

Any voltage shown on any cell is OK, that cell is not shorted. If you read 4 volts or more that is fine, less than four volts and you will have to probe the cells to measure individual voltage, or just charge for a few minutes at C/10 and see if the voltage goes above 4 volts.

Great. Thanx for the advise.