Battery

[duxastrogirl]

Now I have a question for the electricity experts -that it is sort of related- .(sorry to deviate the thread a little) but is something that I am not sure.... Is it the same to put a two D cell remote into a toy that had a two C cell?? I mean the voltage is the same...

[mike van]

Voltage is the same DA Girl, the 2 D cells should last longer. Same w/ C cells outlasting AA's. As long as they are wired the same, so you don't get 3 volts instead or the 1.5 you are after.

[Robotnut]

Dux, technically C's and D's have the same voltage, but not really ???

Voltage of a circuit has to be measured under load.

Load is the rated current output of the battery or power

supply. A voltmeter by its design, applies virtually no load

to a circuit. This is why those Alkalines can read 2 or more

volts unloaded. If you were to apply the rated load to

them, they would read approx 1.5 volts. AA's, C's and D's

are all 1.5 volts with the appropriate load. Items designed

to run on C's can be damaged by D's because these were

designed to apply enough load to the battery to bring it

down to 1.5 volts. This lowering of the voltage is due to

the internal resistance of the battery. Carbon batteries have

a higher internal resistance than Alkalines. The lower the

internal resistance of the battery, the more current it can

supply.

The problem is that vintage toys were designed to run on

vintage batteries. Today's batteries are designed to run

today's devices that require higher current. Today's high

output AA's actually have the same current rating as

D-cells from the 1960's. This is why Rocket USA's R1 and

Metal House's new Piston Robot have no problem running

on AA's.

If you use modern batteries in a vintage toys, you do risk

burning out lights or smoking devices, because they use

a delicate filament. Motors don't usually have a problem with

a little more voltage. They will just spin a bit faster, converting

the electrical energy into kinetic energy. Filaments can only

produce more heat and more heat is bad...

Sorry about the long winded explanation, but you asked... B)

P.S. Most toys are wired in series, so they actually run on 3 volts.

If your batteries are putting out 2.2 volts each, then in reality

your R-35 eyes are being hit with 4.4 volts, OUCH !!!

[dratomic]

Thanks for the break down, Robotnut. I think I'll continue draining batteries in my other, modern toys before throwing them into my vintage pieces. Just to be on the safe side...

[mike van]

Robotnut, I've never seen a load - amperage chart for dry cells. It's not load or amperage that burns out bulbs, it is voltage. The same 1.5 Volt dry cell that powers a motor or electromagnet can also power a light bulb, the problem I see is with the voltage, not with the load. The smaller the load, the longer it will run. Houses near substations can see voltage of 125 125 250 - near the end of the line, it can be 110 110 220. Your typical light bulb is for 120 volt, at the higher voltage, people go through bulbs weekly, until they start buying 130 volt rated bulbs. It has nothing to go with amperage, you can have a 10 kva transformer feeding this house or a 50 kva, a house with a 60 amp service or 400. If you have high voltage, you are going to be buying light bulbs by the case. I will stick to my statement, that if all 1.5 volt batteries put out 1.5 volts, that the size doesn't matter. The larger ones will last longer in the same application.

[Robotnut]

Mike you are correct that 1.5 volts is 1.5 volts, but as

you said most modern batteries have more than 1.5 volts.

Put batteries in a toy and measure the voltage with it

switched off and on. I just tried this with a Hong Kong

Saturn Robot.

Carbon D-cells, 3 volts off and 2.1 volts on.

Alkaline D-cells, 4.4 volts off and 3.6 volts on.

The 1.5 volts difference is like adding a third battery !

Most vintage toys will ususally load two carbon batteries

down to 2-2.5 volts. 2.5 volts is what is stamped onto

the base rim of most of the lights in these toys. These

toys were designed to drop the battery voltage to 2.5

volts for the bulbs. Another thing to never do is to use

an AC adapter to test an old toy. I've measured 3 volt

adapters at 11 volts unloaded ! These adapters are

designed to only deliver the rated voltage when fully

loaded to the maximum current listed on the label.

My first "real job" after college was with GE's electrical

supply division where I discovered battery load charts.

It's amazing how much engineering goes into the

simple devices we use. Larger batteries are used to

provide the required current for a device not to

neccessarily to make it run longer. More load, means

bigger batteries...

[mike van]

Got ya, Robotnut, thats pretty much what I said, that 4.4 volts from the alkalines is whats going to pop the bulb, I didn't have any carbons to measure, but I was guessing they would be 1.5 and you have cofirmed this, thanks. I still believe that size doesn't matter, as long as the voltage is correct. You can run your house off a Coleman generator, or get power from a nuke plant, the capacity of power available won't change the fact that high voltage will burn up light bulbs and electronics, and low voltage will do the same to motors. If your getting 120 - 240, it matters not where it's coming from. Same will apply to dc toys.

[larry seven]

:) Automobile 12 volt batteries mostly test unloaded at 13.5 or 14 volts unless they are on their last breath. -L7

[H.I. Gosses]

Avoid all problem by using Niccads.

They are 1.2 volt each.

(You also avoid the problem of buying new batteries.)

"Btw. you can run your bulbs on 50 kV if you limit the Amperage. "

muttered Mr. Ohm in his grave & turned over.

[9tobor9]

;) This is a great school, which comes to the point with all our newbies. What troubles me is how to get beyond D when your learn alphabet through batteries.