calazans: Minitrans CD TP1 - What kind of batteries were used in this

What battery type and number of cells were used in this radio?

 

The battery compartment floor shows just two batteries engraved on the plastic cabinet. The useful space to install batteries is around 148 mm in length and 21 mm in diameter.

If the radio runs on 6V, then it would make sense to use four 1.5V dry cells even considering the alleged  manufacturing date of ealry 60's. But four dry cells do not fit inside no matter what model is chosen.

So probably two uncommon sized dry cells were chosen for this model. Could it be something like this one?

• 3V "Duplex" / "Ever Ready No. 8" / "2R10" sized as 21.8 × 74.6 mm

 

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Please search here in the forum: Batterie Ersatz and there you will find this contribution from Mr. Heigl

Mr. Heigl suggests to replace the 3 V battery with a 18650 LiIon cell. The  old 3V batteries 2R10 is hardly to find today.

best reggards

H. Stummer

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Thank you for the information, Mr. Heinrich Stummer

That could be a solution to be able to operate this radio since the 2R10 are out of prodution now. I found some new old stock VARTA units in eBay at a very high price, but I do not need them as I am not using this radio.

My question was more related to find out what was the original battery type used in this radio model, since this information is missing. 

 

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The 3V No 8 used 2 x U8 cells

No. 8 73 high & 21.5 diameter. Also called Duplex, Bijou and Pocket Torch battery.

The U8 is an IEC R10 37mm x 21.5mm diameter, no USA designation known. The USA BF was 33 mm tall/long and 19 diameter and was closest to the U8 (U=Unit in UK Ever Ready designations). The A, B or C cells won't fit. The B (U10) was used for HT packs and Gridbias and 3 are in the flat pack used in some rear cycle lamps and  in pairs in some European Continental radios instead of PP9 (9V pack), old name was 1289, IEC 3R12.

I've only ever seen the composite No. 8, in 1960s flashlamps and bever seen the U8. It might have used 4 x U8 or 2 x No. 8

See

Blaukatz dot com Home › Tables › Basic Round Cells

Blaukatz dot com Home › Tables › Other Batteries and Cells

 

My site, somewhat neglected, built from many old catalogues, adverts and R&TVS book tables.

 

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A 18650 Li ion cell is a rechargeable type and best used only in equipment deigned for it due to fire risk.

A CR123 is 3V and non-rechargeable. One and a safety fuse will fit in a No. 8 style replica pack as it's 17 mm dia and about 33 mm long (2/3rds A size = 49mm l x 17 mm dia). The No 8. is 73 mm long and 21 mm dia. It was about 1500mA, same capacity as the single use CR123 camera cell (don't use a rechargeable version).

Shorted Primary Lithium cells can explode or go on fire, hence the fuse. I've proved this with CR2032 coin cells.

A plain cardboard tube (up to 1.5mm thick wall) with cell and fuse can have a printed label if required.

The CR123 and equivalents are available in our local supermarket. It should have a shelf life of over 10 years and is unlikely to leak. Its nominal voltage is 3.6V, but the original Zinc pack could have been 3.3V when fresh and an endpoint of about 1.8V. The Lithium cell will have an end point of about 2.7V. Any radio designed for 4 x Zinc Carbon cells should be fine with 2 x single use Lithium cells, but not rechargeable types as they should have a management circuit in the electronics to prevent complete discharge, because if that happens there is a fire risk when recharging.

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