Yes you can take 3- 1.5 volt batteries, (button cells -hearing aid batteries) also in the shape of a coin style.
and hook them in series, to obtain 4.5 volts.
You then solder a diode in series with the batteries.
The silicon diode has a forward voltage drop of .6 volts.
If it doesn't work its because you put the diode backwards and need to reverse it.
so in series you have 4.5 volts minus .6volts to equal 3.9 volts which should be close enough to 4 volts to operate.

Plus the diode doesn't waste energy like a resistor would.

That is a very good solution. New technology hearing aid batteries have current capacity of approx. 600 mAh and that is enough for many hours of work. Zinc-air batteries for example. And they are inexpensive, I think and easily available. Instead of soldering I would recommend a small battery holder. Please remember that soldering the miniature cells may be hazardous causing explosion from the internal pressure when high temperature is applied!!!

Oops - I meant three 1.5 volt cells and a series diode.

Would get about 3.9 - 4.0 volts

Those batteries contained 3 x 1.3 volt mercury cells. Mercury batteries had a higher energy density than carbon-zinc and a very flat discharge curve.

I don't think they're made anymore because we no longer just toss mercury into the trash.

Time to reopen this ancient thread. I just brought down a Magnavox AM-2 pocket transistor radio that I had stowed away upstairs, and I need an Eveready E233 battery equivalent for it. What's the consensus gentlemen?

The Radiola Guy did an article on this:
http://www.radiolaguy.com/info/Vintage_Batteries.htm

Of course, you can check with http://www.batteriesplus.com/ to see if they will make you a rechargeable.
Won't be cheap, but those guys are pretty darn good.

~ Mitch ~

Thanks for the info Mitch. That may be what I'll have to do.

Yes, that's excellent advice Mitch. A rechargeable would certainly be the way to go. Thanks.

zenithjim,

I use the following A133 4.5 volt battery, found on the Internet by using Google:



Other posters have mentioned the number on this battery. I think I paid about $12 for it, but maybe you can find it for less.

Phred

Thanks Phred. I just contacted BatteriesPlus.com today, and they said that I would have to bring the old Eveready E233 battery to one of their stores for a possible battery pack. That would all be fine, but I don't have an old battery available.

I suppose that I will have to look into the Exell A133 battery then. Thanks.

Hmmm......On second thought, I think that I will just bring the Magnavox AM-2 radio to one of the Batteriesplus stores today, and see what they can do.

Hmmm.....I brought my Maganavox AM-2 transistor radio to one of the local Batteriesplus stores today, and didn't have much luck over there. I suppose my fortunes would have been better if I could have brought them an old Everready E-233 battery to work with.

Well, I ordered two Exell A133 4-Volt batteries (as per Phred's advice) from batterymart.com today, and the shipping charges were very reasonable.

You can buy replacement 4.5 volt batteries on e-bay that power my RCA perfectly............

http://www.ebay.com/itm/230407140439?ss ... 1439.l2649

Thanks Froggy 115. That's certainly a good option. Well, I did scan eBay last night for any old and discarded Eveready E233 battery so I could take it over to the BatteryPlus store today. That way, they would be able to remove the innards and replace the shell with a new battery pack.

On a more serious note, I can't imagine that any of those old Eveready E233 batteries would still be lying around any ways. If they were still lying dormant in somebody's radio, those batteries would now be growing more leaksicles (rusticles) than the Titanic.

Bluster1,

I don't think the A133 4.5 volt battery I pictured above will work with the Magnavox AM-2 radio. The Magnavox radio clearly has two contacts on one end, as this picture shows:



The A133 battery has no such contacts. I was responding to zenithjim (first post), who was asking about a standard 4 volt battery. He didn't provide a radio model number to go by.

Sorry if this series of comments has been confusing.

Phred

Thanks Phred. I'm surely well aware of that. When I receive the batteries from Battery Mart, I'll make up whatever is necessary to insure that batteries can be inserted and removed normally. No soldering or other alteration (on the battery holder) will be required.

Blustar1,

Good to hear you're on top of the isssue. let us know how your solution works out.

Phred

I received the two EN133A 4.5 alkaline batteries from Battery Mart yesterday, and I got around to conjuring up a makeshift battery holder for the radio this afternoon. As you can see, I just cut a small piece of insulator and tucked it inside the original AM-1 battery holder.

Afterwards, I clipped off a small piece of 3/8" diameter spring wire, and tucked that piece betwen the "negative" terminal of the EN133A and the metal ground.

Well, I turned on the radio afterwards, but the battery voltage immediately fell to 4.0 volts (and dropping still further). Unfortunately, there is a short somewhere in the radio as the battery is powering a 104 ohm load. It's the first time that I powered up this radio so I got a little work cut out for me.

Hmmm......It's a rare day indeed when I acquire a pocket transistor radio that's working.

Sorry I didn't see this thread earlier, Bluestar1;

I have several Magnavox AM-5's, and an AM-2. All run just fine using a 6 volt supply. I simply wire (4) 1-1/8" long 1.5 volt cells together, solder the radio's black lead to the ending negative point, and solder a wire to the lead batteries positive, the other end of which I wrap a few turns around the radio's positive terminal.

Given that the AM-5's display the bottom of the circuit board, showing only the PC traces with the back off, I have had NP replacing the Electrolytic caps, in order to get the sets working, since the components are all on the other side of the board, and basically hidden from view.

It's been a different story, however, with the AM-2, since half the components can be seen, hardwired, under the plastic cover. Mine does work, albeit weakly, when I plug a small Rat Shack audio amp into the earphone jack.

I am reluctant to replace any of the Electrolytics in the AM-2, preferring to keep it in it's virgin state, something I do with my rarer Transistor sets. BTW, an AM-2 in reasonably decent (not perfect) shape sold on The Bay recently for $239.00...I think the fact that it was Magnavox's first entry into Transistor sets, and/or the components were hardwired, as opposed to the later PC technique, is what makes the AM-2 far more valuable than the later AM-5.