What to do with a bunch of slightly depleted 9V batteries?

[Katie Wasserman]

(08-08-2014 09:45 AM)kusmi Wrote:  I would go for this ;-)

https://www.youtube.com/watch?v=8hwLHdBTQ7s

I was going to suggest some higher voltage experiments but not that high. The person who did these experiments is lucky to be alive he was extremely careless in almost everything he did.

Using about 15 batteries in series (since you say they measure 8 volts each) will give around 120 volts so you can power some items that you would not think of as portable, a string of old-style, incandescent Christmas tree lights for example. Neon bulbs are fun to play with using medium-high voltage DC; you can make some nifty oscillators by adding resistors, capacitors and diodes. Along the same lines, you can power some Nixie tubes circuits with these discardable batteries, but you'll need to up the voltage for this a bit.