IT LIVES ANOTHER DAY!
The two caps were wired in series, and replaced original cap on the circuit board. Calculations are as follows -
series wired combination of two CAPS --> (100uf @ 160 volts) + (47uf @ 250 volts) = new specs of: 32uf @ 410volts). Or mathematically 1/ (1/47 +1/100) = new 32uf spec. Voltage is simply additive, and regarding voltage distribution, the math is a simple ratio. In this case 100/147 for the lower 47uf cap or about 2/3 of voltage allocates to the 47uf @ 250 volts cap, so then 1/3 of voltages will be at the higher 100uf rated cap. Note, use of resistors to further even out voltages should be done. I did not bother with that so this is more of a quick and dirty replacement.
As it turns out I got lucky, in that these two salvaged caps are actually a very close match to the original single cap specs of
33uf @ 400 volts. The new 32uf rating is almost spot on, and votage drops across each cap are with specs. The higher voltage rated cap could have to take about 10% more that ideal, but only if maximum voltages are exceeded. Not a perfect volt ratio, but dam close, and did I mention that it charged my two batteries - no problem!!
Will post an update in a few weeks or next time I charge batteries because I'm really not sure how much longer it will work -- the faint high pitch hissing noise, or original problem that I noticed when it stopped charging still exists so there may be another part failing that is causing caps to fail.
Anyone venture to guess as to what part is causing the noise?
As usual, I did not follow Steve's usually practical advice. And his answers are sometimes not very supportive for us weekend electrically simple minded hackers; however, I did heed some of his warnings by not cramming both caps inside but instead used a coping saw to cut an opening for the new caps to protrude out the side, and am using protective eyewear and covering wal-wart with heavy insulated glass lid when charging.
Woody