Ever Ready Combination Radio Batteries

The "combination" batteries are those with LT and HT combined. Initially they were for 4 x 50mA type tubes, a total of 250mA as the output tube is usually a 100mA filament(s) or a 3V centre tapped filament.

These are referred to as "Balanced Batteries". The public later was perhaps suspicious that it was a ploy to "waste" batteries. But with Class A and known design, it's a reasonable idea. Not all Ever Ready Sets used Balanced batteries, but certainly more than Pye, Marconiphone or Vidor.

Models prefixed by "AD" means "All Dry*" and may use cylinder cells to make the HT (60 cells for 90V HT). The Alkaline PP3 today uses 6 cylindrical cells that are AAAA or close to AAAA size.   The "B" Prefix was originally marketed as "Batrymax" and used Layer cells, like in a Zinc Carbon PP3 today. This allows less wasted space (hence "max"), which is why a Zinc Carbon PP3 is 450mAH and an Alkaline is only 590mAH and not 850mAH.

B126 Layer cells

PP9 Layer Cells

 

B114 is smallest for a "Personal" Radio (Personal B or B2) so is only about 67V HT. LT is assumed to be 250mA. The similar US sets used one or two D cells and separate. HT. Likely the B114 had one "F" cell (10,000mAH = 40hrs, a DAB set on 4 x AA lasts 5 hours!, The best DAB sets with 4 x Alkaline D cells manage 120 hours!)  and then 4 stacks of 11 layer cells.

A 996 6V lantern battery today still often has 4 x F  cells in series.(First released in 1896!).

So an AD3 (for 250mA originally) is all cylindrical cells (4, 6 or 8 F cells in parallel, I don't know how many) for LT and HT. AA, A and B cells where used for HT packs. 

But a B103 uses Layer cells thus is denser and has better HT capacity for volume. It's also originally for 250mA set. Octal and B7G (7 pin miniature) versions C, C/A, C/E, T and K

In 1953 Philips developed the 25mA Dx96 series, so a four tube set would take only 125mA. Hence the B141 (smaller) and B136 (large) and B137 (largest) are released "balanced" design for 125mA. (Sky Queen was the first to use the B136, then Sky Prince and sky King) then all the smaller valve sets after 1954 used the B141 (Sky Baby, Sky Casket, Sky Baronet, Sky Countess).

With the  Sky Monarch AM (6 or 7), Sky Monarch AM/FM (10), Spacemaster/Skyscraper II (8) and Sky Commander (9) Ever Ready did "cheat" a little. They didn't design a purpose made pack!  The older tubes is like twice as many of the newer tubes and the HT current often a little higher, so Ever Ready used the B103 or B137 pack on these sets (The B137 is a higher capacity version of B136 as option for 125mA draw Sky Prince Table model). These sets all use the Dx96 series 25mA tubes. The SkyScraper L26 uses 5 tubes, but two are DF96 and the rest the older kind so total current draw is correct for a balanced LT HT using the B103. On the AM/FM sets the DK96 heater is disconnected in FM mode.

Ever Ready of course made dry cells for HT (Winner series) before WWII and separate LT & HT batteries to suit all the sets on the market after WWII.  Early miniature layer cells used for 15V and 22.5V batteries for meters and hearing aids (B121). The HT layer cell technology was then the basis of all the PP series of "Power Packs" for transistor sets such as PP3, PP7, PP9.

A separate article will look at choices for making "sensible" replacement battery packs.

[*The Ever ready 5214/ Lissen 8412 are possibly the first "All Dry" due to 50mA 1.4V filaments rather than the earlier 2V 100mA types that required a "wet" Lead Acid cell, though at least one late 1930s Ever Ready/Lissen portable used a "Gel" type Lead Acid 2V, but a 20AH, it wasn't light!]

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You'd think from advertising that an Alkaline battery is far better value than a Zinc Carbon, up to x5. But this is only true for very high currents where Lithium Iron Sulphide (Energiser Lithium 1.5V) or rechargable NiMH or Lithium (designed in) is better value and capacity.

At low to medium drain Alkaline is better than any rechargable cell and has better shelf life, almost as good as Lithium primary cells (Memory backup etc).

At the 6mA to 12mA of  most portable Tube (valve) radio HT batteries the Zinc carbon for same size (i.e. AA cells in a B136) is not 1/5th as good, but 1/2. The price of 10 to 14 off Zinc Carbon AA is €1.50 compared to best discount price of €3.00 approx for 8 off Alkaline AA

So at worse 15c vs 37c, so 10 off Zinc Carbon are only just better value taking into account run time. But the Zinc Carbon are often not fully filled, so the cost is about the same (per hour) and the Alkaline last x2 longer. At €1.50 for 14 cells, though, the Zinc Carbon are winning

PP3 types

But for 10 x PP3 cells to make the smaller packs (B126, Pertrix for German sets, B114) there is the fact that the ratio isn't 2:1  it's 460mAH vs 590mA as even the cheap Zinc Carbon are "full" (unlike the cylinder cells) but the Alkaline uses 4 x AAAA (or slightly shorter). An NiMH AAA (750mAH) cell is shown for comparison which is about 900mAH for Alkaline and 450mAH for Zinc Carbon (or 390mA to 410mA for  current cheap ones which are not completely "full"). The NiMH AAAA cells are about 220mAH and in a PP3 give about 82% to 90% of nominal Zinc Carbon or Alkaline PP3. Some rechargable PP3 do use rectangular button cell, especially when NiCd was common (150mAH).

So an Alkaline PP3 is only about 1/3rd better. (1.28:1 ratio instead of 2:1).  But ZnC PP3 are €1.50 for two and discount Alkaline PP3 €3.00 per pair. Duracell and Energiser Alkaline PP3 can be twice as much again.

So for your PP3 based B126 pack the Zinc Carbon only last a little shorter and cost 1/2 as much.

Another option, especially for leakproof intermittent operation is CR2032 "coin cells". "Is he mad?" you ask. No. Because 200mAH coins including postage are 14c from Hong Kong. You need six stacks in parallel due to internal resistance, which gives then 1200mAH! Also the voltage variation is MUCH lower. The "end point" of  Zinc Carbon is 0.9V or Alkaline according to makers. This would give only 54V! If we take the end point of  2.75V of Lithium CR2032 coin cell, then 26 coins gives 71.5V. The nominal voltage will be 78V and peak 84V. So 6 stacks of 26 = 156 coins, just under €19! But that at 9mA gives 1200 / 9 = 133 hours, thus 14.3c an hour. The Zinc Carbon is 50 hours for €7.50, thus 15c an hour, but the last 1/4 of life of the Zinc Carbon is poor and the Lithium perfect. also you have no risk of leakage and over 10 years shelf life. 6 x stacks of 26 do fit with space to spare in a B126.

There is no doubt that the best value is AA cells if the box is big enough to take them. AAA cells may beat PP3 for value and if Alkaline certainly win on run time in a Pertrix or B141.

The LT batteries can then be chosen to suit the run time of the HT.

A selection of "Ersatz" Ever Ready batteries

• B126, 90V: 5 x rechargeable C cells and Inverter OR 10 x PP3 OR  156 x CR2032
• AD38, 7.35: 5 x B cells from a pair of 1289 Retangular 4.5V cycle lamp batteries OR 5 x Alkaline AA OR 10 x Alkaline AA (with 2 x schottky combiner diodes, and slightly larger box)
• AD35 1.5V: 2 x Alkaline D cells in parallel (same date code and unused)
• B127, 7.5 + 85V: 5 x F cells (4 per 996 lantern) or 5 x Alkaline D cells and 56 x AA cells (7 x 8 way holders or 5 x 10 way + 1 x 6way). For 50mA series sets.
• AD14, 1.5V: 4 x Alkaline C cells (or 8 x Zinc Carbon) in parallel (same date code and unused)
• B107 90V: 60 x AA cells in custom card holder in two layers
• B114 70V + 1.5V: 1 x Alkaline D cell and 8 x Zinc Carbon PP3
• B141 90V + 1.5V: 1 or 2 Alkaline D Cell (or 2 or 3 Zinc Carbon) in parallel (same date code and unused) and 60 x AAA cells in two layers in custom card holder.
• B136: 4 x F cells or 4 Alkaline D cells in parallel (same date code and unused) and 60 x AA cells
• B103: 4 x Zinc Carbon D cells and 10 x PP3, OR 8 x Alkaline D cells and 60 x AA (not sure if it fits!)
• AD3: 8 x F cells (or 6 x Alkaline D ) in parallel (same date code and unused) and 60 x AA cells.
• PP9, 9V: 6 x AA cells in series. Zinc Carbon is less life than real PP9, Alkaline might be nearly the same. 1 x 4 way and 1 x 2 way holders. A PP3 might be unsuited as current drain is often 20mA to 50mA  (most Hacker, Roberts, Fidelity "Rad" family and Sky Leader. If you can actually get a real PP9, it's FAR more expensive than 6 x AA cells, even alkaline.
• PP7, 9V: 6 x AAA cells in series. Zinc Carbon is less life than real PP3, Alkaline might be nearly the same. 1 x 4 way and 1 x 2 way holders. A single PP3 might be suitable, it will be very much shorter life. (Sky Master)  

Note that B103 and AD3 are for sets that take 2 x LT current than sets that use B141, B136 and B137.

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The AD3, B103, B136 and are related. The B114 is for small "Personal" Radio with 67 or 70V HT and the B141 is for Sky Princess, Sky Baby, Sky Casket 25mA more portable sets. The Sky Baronet, Sky Countess, possibly Sky Queen MkII and last of all the Sky Captain have PCBs and use the B141.

Specifications from GEC data sheets (except for B137)

We know the AD3 is all separate cells and balanced also that the B103 and B136 may use separate LT cells but definitely use "layer" cells for HT, resulting in better HT power density.

Rear: Lissen 8515 similar Ever Ready All Dry Portable 5214, All Dry Model C/A and Sky Queen
Front: AD3 prototype with 6 x F cells in 2 off 966 packs,  Batrymax B103 and B136 Radio Battery

The rest of the space of the AD3 (Originally "All Dry Number 3") is probably filled with 60 off "B" cells in series standing vertically. The space is 283 - 90 long = 173 L, 70 H, 149 D. The  "B" / U10 / R12 cell is  less than 57mm tall and 17mm diameter when "naked"

The 996 Lantern Battery has 4 off  "F" cells in series. Zinc Carbon capacity is 10,500mAH

The 1289 / 312G / 3R12 cycle battery (used in some German radios) has 3 off "B" / U10 / R12 cells in it. Zinc Carbon capacity is quoted as 1200mAH to 2500mAH . Since the Alkaline is quoted as 6100mA, and Zinc Carbon is half the capacity at low currents, the 2500mAH seems beliveable.

So AD3 on a 250mA LT and 9mA HT based on these figures would be

LT 10500 x 8 = 84000 mAH, 250mA thus 336 Hours. The figure mentioned in connection with some 250mA sets is 300 Hours. So 8 x F cells in parallel seems believable. There is an LT only  battery pack known to be 8 off "F" cells in parallel for 1.5V.

HT is 2500mAH since the cells are in series. 2500 / 9 =  278 hours approximately. It should be noted that the 10500mAH is an endpoint of 0.9V. It's likely that the valves work better with 1.1V LT and 55V HT than 0.9V and 70V for example as they are mostly Pentodes. The DAC1 triode HT is quoted as 12V in the Trader sheet! So it's more important that the LT doesn't get too low. So 277 hours is actually more reasonable than 336 hours for the LT.

B136 contents

The Sky Queen (first Every Ready set to use the 25mA tubes) only takes 125mA, so logically the B136 only needs 4 off "F" cells to have roughly the 280 hours of quality filament voltage. The Service sheets for Sky Queen claim 10mA HT. So about 2800mAH is needed in the layer cells. The PP9 layer cells are 5000mAH. The space left by putting 4 x F cells is about enough and a little more for 30 off PP9 layer cells, so the B136 probably did use 4 off "F" cells and not the shorter D Cell.

 

B137 contents

Both the B136 and B137 are originally for 125mA LT and 8mA to 11mA HT. The Ever Ready Sky Prince rear cover recommends B136 and optionally B137, which is the first mention of the B137. The B137 is also recommended for one of the later "HiFi" Ever Ready Table  models, possibly the Sky Monarch (II) AM/FM.

The B137 is slightly more than twice the volume. Possibly it used PP9 sized layer cells and 8 off F Cells to give over 500 hours on the Sky Prince!  The Sky Monarch II (AM/FM) is 300mA LT (if all tubes on) or 275mA when DK96 is off. HT current depends on volume as the pair of DL96 are in "push pull" class B, however it would seem to be 20mA to 30mA. Thus the LT is 3x the Sky Prince and the HT is about 3x the Sky Price. This means that though it has 10 valves (including DM70), the ratio of LT to HT is similar to the post 1953 four tube Dx96 sets. The B136  would be only be about 90 hours, a bit low for a "Farm" or "HiFi" Table model. The B137 should give it nearly 190 hours. Perhaps 200, not much different to a Model T on a B103 (the Table Model or Farm set based on Model K, and predecessor to Sky Prince, the K is the replacement of C. The 851x/521x, A, C, C/A, C/E, K and T are all similar LT of 250mA and roughly 8mA to 11mA HT).  

So what is in a B103?

Since the Model C (octal) or C/A or C/E all take 250mA LT and roughly the 8mA to 11mA HT of the original "All Dry Battery Portable"  Lissen/Ever Ready, and it's lighter yet has denser layer cell HT, it must have less F Cells. It could be using 6 x F cells  or 8 x D cells (Zinc Carbon of course). This would be about 210 hours assuming about 280 hours for the AD3. The 60 off layer cells take proportionately less space than cylindrical cells for same capacity.  

 

Modern replacements  with nearly Authentic Run time

Oddly the oldest combo battery, the AD3 saw fresh use for some of the later 50s "HiFi" table models and the  hardly sold Ever Ready Am/FM Sky Emperor / BEREC Commander (VHF didn't start in UK till 1955, it was a VERY slow roll out Nationally and ONLY had a Simulcast of the three BBC AM stations. On AM in UK people also got "Athlone"/"Radio Eireann" and at night various European stations including Luxembourg)

AD3

If you want you can buy 2 off 996 packs and 20 off  3R12 / 1289 / 312G packs and make an "authentic" AD3. Alternatively you can use 6 x Alkaline D cell  in parallel (same date code and unused) and 60 x AA Alkaline cells. All in holders. (10 way AA holders are easily available). This will be about 220 hours. For closer to "Authentic" wieight and run time you can fit 8 x Alkaline D cells  and ttwo sets of 60 off Zinc Carbon AA cells, either in 12 off 10 way holders or 15 off  8 way holders (with cut llinks) and a pair of 1N4148 diodes to combine the "stacks". This will give about 250 hours to 300 hours depending on Zinc Carbon AA quality.

B103

The cheap solution is 4 x Zinc Carbon D cells and 60 cheap Zinc Carbon AA cells. This is roughly balanced at 110 Hours. Use  Alkaline D (or 4 off F cell) and Alkaline  AA  for about 220 hours, close to original wieght and run time.

B136

You only need 1/2 as many LT batteries. 60 x AA cells fits with plenty of extra space. It won't match the original for HT run time (110 hrs Zinc Carbon, maybe 240 hours Alkaline, original close to 300 hours on 4 x Dx96 family valves).

B137

If you want to have twice the capacity use two sets of 60 x Alkaline AA cells  (cheaper than 60 x C cells, though they might not fit) paralleled with a pair of 1N4148 diodes to combine. This is about 5400mA so 600 hours HT on Sky Prince and about 200 hours on a Sky Monarch II (AM/FM), though the Sky Monarch is extremely rare.  You would want 8 off Zinc Carbon F cells or maybe 6 to 8 Alkaline D Cells. There is space for 8x "F" cells and 2 x 60x AA cells in 10way holders, with to spare. Use corrugated card!

 

Alkaline vs Zinc Carbon

An Alkaline "D" is easily the same capacity or a bit more than a Zinc Carbon "F" cell from an 996 battery. it should be noted that the actual mAH depends on current (load) and Zinc Carbon only have about 1/2 the capacities quoted here on "heavy" loads. Modern IEC tests specify particular values of resistive loads for particular cells. Usually much lower values for "bigger" cells so that if you put a "larger" battery on something with low consumption you'll get better than normally quoted life and and if you put an AA into an adaptor for something that uses D cells for heavy load, you'll get much shorter life than quoted. The Energiser Lithium 1.5V is only twice as good as an Alkaline and TEN times better than Zinc Carbon on a very heavy load. At a "light" current the Alkaline is just as good (and a lot cheaper) and the Zinc Carbon only 1/2 as good as the Alkaline or Lithium Iron Suphide rather than 1/5th and 1/10th!

PP3 batteries.

These are popular for HT on battery valve sets and the only viable alternative method to 156 off CR2032 coin cells in a B126 pack. But the Zinc Carbon is only about 40 to 45 hours and the twice as expensive Alkaline about 55 hours  to 60 hours. 

F Cells from 996 packs

Some 996 packs use D cells in adaptors! A real "F cell" 996 is about the same price as Zinc Carbon D cell and can be 1/2 the price of discount unbranded Alkaline D Cells, so can work out cheaper. Otherwise Alkaline D, C and AA cells are usually best to make up filament battery packs.

B or U10 from 3R12 / 1289

These are generally more expensive per cell than an discount Alkaline AA cell and only slightly better capacity.  Good for authenticity of AD3 or AD38 7.5V pack.

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Here is an Advert in the BBC's "Radio Times" program guide in July 7th 1939. It features what is surely one of the very first Ever Ready 521x / Lissen 851x models that uses the All Dry Number 3 Combination pack, known later as the AD3. The advert claims at least 240 hours battery life. My estimation of about 280 hours for  60 x R12/U10/"B" cells and 8 x "F" Cells is from currently produced Zinc Carbon batteries contained in 3R12 (1289) and 996 packs!

The AD3 according to GEC is about 3.8kg. As best as I can tell on the bathroom scales the Lissen 8515 is about 3.7kg. The battery doubles the weight! So total about 7.5kg? I bet she was good at arm wrestling :-)  Actually the advert says 18¹/₂ lbs which is 8.4kg! Previously "Portables" used Lead Acid batteries.

 

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Taking the best information on B137 (contemporary catalogues and space in Sky Prince) it's evident the B137 had Eight "F cells" (R25). This means the HT layer cell needed to be about 5000mAH for balanced operation, which is the rating of a Zinc Carbon PP9. Four stacks  of  15 cells lie very well in the box beside 8 vertical F cells. You can also fit 10 x PP3 in the box. I suspect many of the PP range are based on using 6 layer cells of the 60 used often in four series stacks in the "Batrymax" HT packs.

This means on the Sky Prince and Sky Lord the pack would last about twice as long as the AD3 on a set with DK1 DF1 DAC1 DL2,  replacement Octal tubes or pre-Dx96 series 7 pin mini tubes, thus at least 480 hours (as the 1939 All Dry claims 240+ hours). The Model J possibly used the AD3 or a custom BEREC branded pack and its design target was 300 hours (DK91, DF91,DAF91, DL92, possibly a 1952 version added BC(MW) and used DK92 DF91 DAF91 and DL94) The J (Saucepan) could even have used "economy mode" (half filament on DL92 or DL94) which would increase running time by 11% 

Using 8 x F cells and 10 x PP3 (all Zinc Carbon) will give close to original weight and running time.

I've verified that two sets of 60 x AA in 12 off 10 cell holders will fit with space to spare along with 8 x F cells or 8 D Cells.

Using 120 off cheap Zinc Carbon AA will only give ²/₅ths capacity. to match the efficient packing of the layer cells you need Alkaline AA. Two sets of 60 can be paralleled with a pair of 1N4148. Then you can use 8 off Zinc Carbon F cells from 996/4R25 lantern packs or use 8 Alkaline D cells.

When paralleling cells always check they are about the same voltage and from same date code.

If using Zinc Carbon AA x 120, you get double the normal Zinc Carbon mAH, about 2000mAH. So you need only 4 F cells or 6 x Zinc Carbon D cells to be approximately balanced.

Of course if you don't care about authenticity you could fit less batteries and include a mains PSU in the box.

A photograph or scan of a real B137 would be appreciated!

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These also use the AD3 Combination balanced battery pack for well over 240 hours.

(The 240 figure is almost certainly marketing chosen as at 10 Shillings for a battery they can say the Radio is less than ¹/₂d (a half penny) per hour)

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Some  Ever Ready combo packs actually don't use F or D but the rarer E size cells, 32mm dia approx like "D" and "F" but about 74mm long. The 126 Bell Pack with terminals (4.5) also used E cells, though late versions have a polystrene spacer and 3 x "D" cells

B114 used E x2 (parallel)

B103 used E x11(parallel)

The AD35 also probably used E x2 cells originally but late models may have used  D x2 cells.

It's not clear yet if the B136 and B137 used F (4 and 8) or D (6 and 12) or E (5 or 6 and 10 or 11 for B137). No information on the "super capacity" B130 for the Model T either yet as alternative to B103 as the B137 was "super capacity" alternate to B136 for the Sky Prince.

 

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