Old Fashioned battery tester

[Stormin Mormon]

My Dad showed me how to do this, when I was a boy. Take a flash light bulb (PR-4 is good, the old screw in 112 is better, more close to the proper voltage). Then, take about six or seven inch long piece of #10 or #12 solid wire. Wrap one end of the wire around the bulb. Curve the rest of the wire, so it looks like a letter C, or G.

Touch one end of the battery to the lead spot, on the bulb. Touch the other end of the wire to the other end of the battery. If the bulb lights, the battery is OK. Works for AAAA through D cells. Have to bend the wire a bit, for different sizes.

After using this for a while, you can also roughly guess the battery state. New, used, weak, dead. By how bright the light is.

[greenpjs]

Note that this kind of tester was required back in those days because old carbon zinc batteries required a load to be properly tested. Their open circuit voltage was misleading. However, with alkaline batteries, you can get a pretty good idea of their state by looking at the open circuit voltage. Your method works with either situation, though. (I didn't see the OP's original question, so this response may have nothing to do with it. Your response just brought back memories of letting the batteries rest a while so I could get a few more minutes of listening out of my transistor radio while sleeping out in the back yard on a summer night).

[stan]

Yeah reminds one of those testers that looked like a pair of calipers with a flashlight bulb mounted at the junction. The arms were kinda curved; the storekeeper would touch each end of the 'calipers' to a battery and tell you you needed to buy a new one. Different voltage bulbs could be screwed in; but it was generally used for testing single 1.5 volt cells. If I recall a D cell (in the UK called a U2, long before the musical group or the spy plane) cost in the late 1950s about sixpence. And one needed two of them to power the mandatory little red light on back of the bicycle to get through one winter to and from work!

[Joe]

Here's an even older test method I got from a regular army old time communications sergeant back in 1940: if you need to check the batteries in your EE8A field telephone, wet your finger and place it on the bottom of the battery, then touch your tongue to the center electrode. A good battery will give you an 'electrolytic' taste which will quickly let you know which batteries to pitch and which can be used. No tools needed, works every time, even with artillery shells whoofing overhead. It's a bit much for cells over 6 V or so, not recommended for 9V. I doubt if many of today's squeamish citizens will have nerve enough to try it, but this is just for the record and people with a git 'er done attitude.

Joe

[greenpjs]

I've used a similar method for many years. To test 9V batteries just touch your tongue to the two contacts simultaneously.

[G. Morgan]

I suddenly have a mental image of WWII troops landing at Normandy...

... amidst all the fighting there is a curious soldier running around licking batteries.

[Jeff Wisnia]

Shall I alert the Nobel Prize committee?

Jeff

[Stormin Mormon]

I'm the OP. There was no question. I was sharing a trick or technique I'd used for a while.

Hmm. Wait a while for some more power from the batteries? That sure sounds like the old carbons.

[Stormin Mormon]

Thanks, your mental image was a bit more ammusing than mine.

[Stormin Mormon]

Aw, shucks. I'm just too down home purty fer that!

[Clot]

Been there and done that when I was a kid in the 50's. Warming them up helped.

[The Daring Dufas]

If you stick a 98 volt B battery to your forehead, there is a bit of a sting and your vision starts flashing rapidly. ERK, there's nothing wrong with me. ERK, there's nothing wrong with me. ERK, there's nothing.............

TDD

[Jeff Wisnia]

So you remember those B batteris too, 'eh?

How about those 225 volt (?) dry cell batteries which were used in pairs to make 550 volts for the early still camera strobe flashes circa 1950 or so?

You could get a nice jolt out of them.

Jeff

[The Daring Dufas]

I had a Graflex strobe 4 that used them. I was shooting

2 & 1/4 by 2 & 3/4 film at the time, but that was 35 years ago. Those batteries were fun because I could freak people out by inserting test leads into the battery and striking a fairly long arc. I've become lazy now and have succumbed to cheap digital cameras.

TDD