EverReady #477 Battery Substitute

For Portable Tube Radio Sets

October 2011

Many portable tube radio sets were designed to use a

67½ Volt “B” battery. An original EverReady #477 “B”

battery is shown on right side of this page. In this

paper I will describe how to make a nice-looking

substitute battery for the #477 type, using seven low-

cost 9-volt transistor radio batteries.

I saw a YouTube video showing a replica #477-type

battery that used six of the #A23 12-volt alkaline

batteries. But the #A23 has only between 30 to 40 mAH

capacity when the load is between 10 to 5 mA,

respectively. Therefore such a battery has a useful

life, for typical portable tube radios, of at most 4

hours. The total battery cost is up to $24 ($8 per #A23

2-pack from Radio Shack), plus tax.

Another approach, which is cheaper and more common, is

to use seven 9-volt alkaline or “heavy duty” transistor

radio batteries that are stacked and wired in series.

The capacity of the “heavy duty” type in this service

is about 250 mAH, for a useful life of at least 25 to

30 hours in a typical portable 4-tube set. My total

cost for seven “heavy duty” 9-volt batteries from

BigLots was $3.33 plus tax ($1.90 per 4-pack). I have

chosen this approach.

The width and length of a standard 9-volt battery are such that the

stack will be about 1/32” thicker and about 1/32” narrower than the

specified maximum dimensions for the #477. You should use one of the 9-

volt batteries to check that your battery compartment will accept the

slight additional thickness. My stack of seven 9-volt batteries is 4 and

5/8” long, while the finished battery is to be about 5 and 5/16” long,

not including the snap connectors. See drawings below and on the next

page.

In order to keep the finished width within #477 width, the terminals of

the 9-volt batteries must be soldered using small (AWG22) wire jumpers

placed on the inside edges of the 9V snap connectors. I used rubber

bands to hold the battery stack together while installing the series

wiring. I used a small chisel-tip professional Weller iron. I tinned

each connector and jumper first, and then held the jumper onto the

connector for as short a time as possible to make a good joint. Avoid

excessive heating of the connectors. See photo below;

This “heavy duty” battery stack measured 70.5 volts after the partial

assembly shown above. The rubber bands and the temporary wood block will

be removed during final assembly.

The snap connector block is fabricated from salvaged snaps and a

homemade 5/8” thick wood base. To make the snap connector block, I used

left-over pine base molding to make two 5/16” thick wood blocks which I

then glued together using a very small amount of Elmer's white glue.

Here is a template drawing for making the wood blocks. I suggest using

cereal box cardboard to make the template.

The “B” battery snap connectors must typically be

salvaged from old batteries or scrap (non-restorable)

radio sets. The snap connectors are mounted to the

wood block spacers using the #18 wire nails passed

through the connector rivets. Carefully drive the

nails through the rivet holes of your connectors and

into the blocks, using a tap hammer and an upside-

down and slightly larger flat head nail as a nail-

set. Check that the rivet heights of your connectors

kept the 5/8” long nails from poking through the back

of the wood block unit, or else use shorter nails. I

cut shallow grooves in one side of the block to pass

the snap connector wiring back to the battery stack.

Secure the snap connector block to the battery stack

with rubber bands while wiring the snap connectors to

the battery stack, taking care to observe polarities

(positive = battery male, negative = battery female).

Using the cereal box cardboard, make a 15/16” x 5 1/4” strip to lay over

the connectors of the battery stack. This will help to protect the

connectors from possible punch-through and shorting during handling and

installation of the finished battery. I suggest placing the unpainted

side of the cardboard towards the batteries.

Make a 6 3/4” x 5 1/4” plain paper inner wrap to support the battery

assembly. Use short strips of cellophane tape to fasten down snugly the

plain paper over-flap. This inner wrap does not fold over the ends of

the assembly. If you don't do this inner wrap, the replica label will be

harder to place and install. I used cellophane tape strips to secure the

replica label to the battery stack. On next page are photos of 1) the

finished replica battery, and 2) my Emerson model 850 set with this

battery and my G cell adapters installed.

The finished battery will not have the beveled sides of the #477, but

otherwise should look and perform very fine in many sets that required

the #477.

On the next page is my replica paper label, sized to this stack design,

that can be wrapped around the finished battery assembly to provide

support and aesthetic quality. The under-flap is on the left. Use the

grid (1-inch centers) to check and adjust image size before printing.

THE END