Use dummy cell in two cell battery charger?

At home I use an "intelligent battery charger" which charges cells two at a time and both must be present for the charger to work.
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THE PROBLEM ..... Sometimes I want to charge just one cell on its own.
Maybe that one cell is an AA or AAA from a single-cell MP3 player. Or maybe I have to recharge cells which have very different capacities or charge levels.
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To charge only one cell, can I put a resistor in the place of the second cell as a sort of dummy cell? If so then what values might I use?
I figure the Negative Delta V sensor would still trip correctly with one cell as it's unlikely that two cells would reach their voltage drop simultaneously.
Tech details are below. Thank you for any info.
Alex
--------------------- TECHNICAL DETAILS ------------------- INFO ABOUT CHARGER ...
The charger is a Vanson V-1000 charger which uses Negative Delta V.
The spec says AA cells are charged at 350mA and AA cells at 750mA. I read 1.45 volts across one 900mAh AAA whilst charging 2 of them. I read 1.35 volts across one 2000mAh AA whilst charging 2 of them.
Manufacturers info: http://www.vanson.com.hk/details/p3001.html Wholesaler's info: http://preview.tinyurl.com/22jdld
INFO ABOUT CELLS ....
Use mainly NiMH with some NiCd AAA cell capacity ranges from 300mAh to 900mAh. AA cell capacity ranges from 1000mAh to 2800mAh. -------------------- END OF TECH DETAILS -------------------
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Well, you "intelligent" charger isn't quite so smart, is it.
They are hard to find but it's still possible to buy chargers that can charge single cells or any number of cells up to 4 or whatever. I got one from Wally World a few years ago. Radio Shack might still stock one that can handle C's and D'c along with the AA's and AAA's. Get one.
When you charge cells in series one cell will be undercharged and/or the other cell will be overcharged.
That said, if you routinely use cells in pairs, you can make a case for ALWAYS charging them in series. When you discharge the "weaker" cell might actually be "reversed" charge when it runs out of juice while the "strong" cell is doing just fine, thank you.
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Buy a charger that charges and monitors each cell individually.
Try www.thomasdistributing.com for a huge selection (no relationship with them; just a longtime customer). The Maha/Powerex chargers are particularly well regarded.
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I bought the smaller 8 cell charger. The instructions seem to be wrong in turning on "condition". I have to hold both buttons in to engage.
I had at least 3 dozen NiMH, some 8-9 years old. My 4 best Nexcell's I found out are worthless. Very high impedance. The 4 newest 1400 ma hr seem to be the best, and out of all of them I saved 12. The other 8 are usable but not the best of condition. Just sitting around seems to have the cells go bad after some years. I judge an old battery by the charge discharge period, and high impedance cells have very short intervals. I need some new cells.
greg
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Make a cell out of a bit of wooden dowel.
Drill a hole through the wooden cell
Connect two 1N4001 diodes in series
Pass the diodes through the hole in the wooden cell
Coil the ends of the connection to the two diodes so that they lay flat on the ends of the wooden cell.
Fit the wooden cell in place of one cell, the diode "cathode" is the minus terminal.
Arthur
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