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Tips and Frequently Asked Questions

Is it easy to change the battery of a watch?
What about 'luxury' watches?
What is 'low drain' and 'high drain' all about?
How do you handle watch batteries?
Can I use an alkaline battery?
How Are Batteries Rated?
How can corrosion from leaking batteries be cleaned?
How can a 1200mAh RCR-V3 out perform 2100mAh AA NiMh batteries?
Any Hearing Aid Battery Tips?
Is there an equivalent battery to a 1.35V Mallory RM450 or PX450 mercury battery?
Do you know of a replacement for the Energizer 538 / K31 Type K battery?
Do you know of a replacement for the PX825 battery?
Do you know of a replacement for the PX13 / PX625 / MR9 Mercury battery?
Do you supply the CR2335 battery?
What Battery do I require for my Praktica Camera?
Do you have a battery for a model 240EE Bell and Howell 16mm movie camera(1958 vintage)?
What Battery do I require for my Yashica Camera?
Is it easy to change the 'Non-replaceable' batteries in Polar Transmitters?
Why are 3.6V AA cells such a tight squeeze in the VR3?
I need a 1.5V Eveready U10 for my AVO meter. Is there a replacement?
I need a new Tomtom 700 battery. Is there a replacement?
Please advise on the battery required for a Ronson electronic Varaflame cigarette lighter
MRB625 and Gossen Lunasix.
Can you make the tabbed cell I require (Wire Glue)?
Can you explain "passivation"?
Does the Fujica ST701 camera work with H-B Adapter?
Is the ZA5 or PR63 still available?
MR-9 Adapter and Leicameter MR.
I am looking for an Eveready 1915. Can you help?
Can you help with other 3V 'Duplex' batteries?
Do you have a UCAR 201 or Energizer / Eveready 201 battery for my LIP watch with R27 movement?

Is it easy to change the battery of a watch?

It is quite straight forward to change the battery of a watch. All you need is a knife or small screwdriver (depending on the watch) to take the back off. A pair of plastic tweezers is a desirable luxury. If you must use your fingers, avoid greasy hands. Sometimes a special tool is required for screw type backs. You can get them here at JewellersEquipment.co.uk

What about 'luxury' watches?

As much as we would love to sell you a battery for your solid gold Rolex, please don't set about it with a blunt screwdriver. Leave very expensive watches to trained specialist dealers.

What is 'low drain' and 'high drain' all about?

Some sizes of miniature watch batteries used to be made in different versions for different uses (high and low current drains). For example, 'Low Drain' versions were recommended for watches that have no light, alarm or LED display, whereas 'High Drain' versions were used for watches that do have a light, alarm or LED display. However, advanced in battery technology mean that, for modern replacement batteries, this distinction is no longer necessary -- one version fits all. We do stock 'Low Drain' variants, but unless there is a price penalty for our customers, we will typically supply the high drain version.

How do you handle watch batteries?

Handle watch batteries either with plastic tweezers or with clean, dry, non greasy hands. Do not use metal tweezers.

Keep watch batteries away from children. Ingestion by infants and children can cause serious illness or death Should someone swallow a watch battery, seek immediate medical advice.

Make sure that no metal objects, such as another battery, 'shorts' the battery whilst it is in storage.

Can I use an alkaline battery?

Some sizes of batteries are available as both Alkaline cells (often indicated by a prefix of LR) and Silver-Oxide cells (often indicated by a prefix of SR).

Silver-Oxide cells are normally used in watches. They are a little more expensive but last much longer.

You can always replace an Alkaline cell with a Silver-Oxide one of the same size, but not always a Silver-Oxide with Alkaline cell. For further information click here.

How Are Batteries Rated?

There are two ratings on every battery -- volts and amp-hours (Ah). The AH rating may also be given as milliamp-hours (mAh), which are one-thousandth of an amp-hour. The voltage of the new battery should always match the voltage of your original. Some of our batteries will have higher amp-hour ratings than the original battery found in your device. This is indicative of a longer life expectancy (higher capacity) and will not cause any incompatibilities.

How can corrosion from leaking batteries be cleaned?

In order to clean the corrosion off your sensitive equipment you will need the following:
Mild Acid – Vinegar or lemon juice. You can use any regular household variety 
Cotton swabs (also known as Q-Tips or cotton buds) – Used to apply the vinegar / lemon to terminals and hard-to-reach spots 
The electrolyte inside most batteries (Alkaline, Carbon Zinc, Silver Oxide, Mercuric Oxide) is Sodium Hydroxide or Potassium Hydroxide. These are corrosive alkaline solutions. So using a mild acid neutralises the alkali and reacts with, and helps dissolve, the other oxide, carbonate and sulphate complexes that constitute the corrosion.

STOP PRESS: We now stock Corrosion Gone! a specially formulated mild scouring paste that is ideal for this job. Look at our Corrosion Gone! page.

How can a 1480mAh Li-ion CR-V3R out-perform 2100mAh AA NiMh batteries?

The energy content of NiMH batteries such as the 2100mAh rechargeable AA batteries are measured by draining the battery from its 1.2V 'notional' voltage right down to 0.9V. Unfortunately, long before that point, the voltage becomes insufficient to power a high drain device. Digital cameras will shut themselves down. Flash guns take so long to recycle that the photographer gives up. 

Lithium-ion has a notional voltage of 3.6 volts and the voltage remains high right until the end of its battery life. It will keep powering high drain devices until the bitter end.

Another way of looking at it is that milli-amp hours (mAh) is only useful for comparing batteries of the same chemistry where the voltage produced over time is similar.

mAh is not useful when comparing differing chemistries such a a pair of NiMH batteries producing 2.4 volts with a Lithium-Ion battery producing 3.7 volts.

To compare dissimilar batteries it is better to consider the energy content in watt hours (Wh). Watts are calculated by multiplying current with the voltage and it takes account of different voltage patterns.

so for NiMH batteries:    2300mAh x 2.4 volts => 5.53 Wh

for a CRV3R battery:     1480mAh x 3.7 volts => 5.48 Wh

In fact this is still not as flattering as the Li-ion chemistry deserves. NiMH cells spend most of their time producing less than their 'notional' voltage. An average voltage of 2.1 volts would be more appropriate for the calculation. And Li-ion drops to 3.7 towards the end of its charge cycle. An average voltage of 4.1 volts would be more appropriate. 

These voltages suggest an energy content of 4.83 Wh for the NiMH eclipsed by 6.1 Wh from the Li-ion CRV3R.

These figures are very similar and, given that much equipment ceases to operate at the low voltage at the tail end of the NiMH charge cycle, it is easy to see how many users report that 1480mAh CRV3R comfortably out- perform a pair id 2300mAh NiMH batteries.

Any Hearing Aid Battery Tips?

The average life of a hearing aid battery varies from 1 to 4 weeks depending, amongst other things, upon the size of the battery, the power of the hearing aid and the setting of the volume control.

Your battery need changing if you find that you need to turn the volume up more than usual, or if sounds are distorted or, of course, if your hearing aid is dead.

For further information on hearing aid batteries, click here.

Is there an equivalent battery to a 1.35V Mallory RM450 or PX450 mercury  battery?

This is a common question from users of Bolex P1, P2 and P3 cine cameras and users of the Alpa 10d camera. 

This battery goes by a number of names: PX450, RM450, RM450R, E-450 and was 11.6 mm in diameter and 14.5 mm in height.

Unfortunately, no one manufactures a exact size replacement to the RM450 any longer. The best you can do is to take a cell of the same diameter and pad its height out with metal washers or some type of wire spring/clip. Scrunched up aluminium foil seems to work nicely. Don't be daunted. It has been successfully done before.

You have two choices for the battery, the silver oxide 1.55V 357 or SR44 or the zinc air 1.35V WeinCell MRB675. Good luck.

STOP PRESS: An RM450 adapter is currently in stock. Look at our PX450 Adapter page.

Do you know of a replacement for the Energizer 538 / 7K31 Type K battery?

This bizarrely shaped 4.5 volt alkaline battery (also known as a 7R31 or RPX31)  is used in a variety of Minolta 110 cassette cameras. 

These batteries are no longer made and, because of prohibitive tooling costs, are unlikely ever to be made. Your only chance is to rebuild an existing one. Even if you were able to purchase a 'new' battery, it might well be too old to have any juice left and would need rebuilding. The definitive source of information on rebuilding is:


Ron Schwarz has some for sale here..... http://www.clubvb.com/Focal.Yokels/SizeKbatteries/Default.htm

Do you know of a replacement for the PX825 battery?

STOP PRESS: This battery is currently in stock. Look at our PX825 page.

The PX825 was a 1.5 Volt Alkaline button cell that is no longer manufactured.

It was also known as the LR52, EPX825, V825PX, HPX825, RPX825. Its NEDA designation was 1129AP.

These batteries were used to power Minox C4 flash cubes, Vitessa 500AE cameras, Agfa Rapid cameras, Agfa Agfamatic 126 cameras, Kodak Instamatic reflex cameras and many others.

The PX825 was of the following dimensions - Diameter: 23.2 mm. Height: 6.1 mm.

If your application requires two PX825s in a 3 Volt stack, then you are in luck. We offer the three volt PX30-L. It is the modern equivalent of the PX30 battery that was composed of a stack of two PX825s.

If your application requires a single PX825 the best solution will be a 357 or SR44 1.55 volt battery which has a diameter of 11.6 mm and a height of 5.4 mm. The 357 is fractionally slimmer than the PX825, so you may need to carefully bend the electrical contacts or add metal washers to make the necessary electrical contacts. Because the diameter of the 357 is very much smaller than the PX825 you will need to devise a method of keeping the 357 centred and motionless in the battery compartment. For example, try cutting a hole in a disc of foam or sponge for the 357 to sit in.

I'm afraid that improvisation is sometimes needed when replacing these discontinued batteries. Good luck.

Do you know of a replacement for the PX13 / PX625 / MR9 Mercury battery?

There are four replacements: Alkaline LR9s, Silver Oxide S625PXs, Zinc Air MRB625s and voltage reducing MR-9 Adapters.

Alkaline LR9: The cheapest alternative is the LR9 (http://www.smallbattery.company.org.uk/sbc_lr9.htm). The problem with the alkaline LR9 battery is that voltage is not the same as the mercury original and, with very few exceptions, the circuitry of the light meter is simple and cannot compensate for this difference. This is very probably the case for your camera. When the battery is fresh and the voltage is c. 1.5v the voltage is higher than the original mercury cell. This voltage difference will result in a one to two F-stop under-exposure in conditions of strong light.

This doesn't normally cause a problem because today's films are very tolerant to under-exposure and because the under-exposure is compensated for during printing. (so you would have greater problems if you were using slides).

You could manually compensate by a couple of stops or by tweaking the ASA setting, but, unfortunately when the alkaline cell is no longer fresh and is getting towards the end of its life, the voltage will drop to, say, 1.2V. This is less than the original mercury cell. This voltage difference will result in a one to two F-stop over-exposure.

Again, unless you are shooting slides, there is often not too much of a problem.

Silver Oxide S625PXs: One solution to this problem is to use a Silver Oxide 1.55V equivalent, the S625PX.

Look at our web page http://www.smallbattery.company.org.uk/sbc_s625px.htm and you will see that this battery has the benefit of a constant voltage. There will always be an under exposure of one/two f-stops but, once you work out the difference (calibrated by comparison with another light meter for example), it will be constant.

Zinc Air MRB625s: Probably the best solution of all is the specially designed WeinCELLS, the MRB625 (http://www.smallbattery.company.org.uk/sbc_mrb625.htm). The MRB625 cells use Zinc air chemistry with a notional voltage is 1.4V (too close to that of the mercury cells to tell the difference). Some people think there is a slight (1/2 f-stop) under exposure, many think it is near enough an exact voltage replacement. The manufacturers claim that this IS an exact voltage replacement. In any case, in practice, today's film and development seem to work perfectly well with the MRB625

Unfortunately these cells have a short life. You pull off the sticky tabs to allow air into the cell and from that point, irrespective of how little you use the MRB625, it begins to dry out and you have a battery life of six months (and sometimes up to a year). The life is certainly very much shorter than the couple of years you might expect from the silver oxide cell.

Voltage Reducing MR-9 Adapters: The "Rolls Royce" solution that can be used again and again. Buried within the MR-9 Adapter are micro electronics that drop the voltage from the silver oxide cell to the 1.35 Volts that your  camera was designed for.

No adjustment or modification to your camera is required. The MR-9 Adapter does not require activation or a supply of air. The MR-9 Adapter and silver oxide 386 cell has a significantly longer battery life than the zinc air WeinCELL MRB625 batteries.

Hope that helps.

Do you supply the CR2335 battery?

STOP PRESS: This battery is currently in stock. Look at our CR2335 page.

I don't know if you have realised yet, but the CR2335 is an exceedingly rare battery. Virtually no one makes then, and we have been unable to secure a source for a long time now. You are quite unlikely to find a CR2335.

You need to examine the possibility of substituting a lithium cell of nearly the same dimensions. The CR2430, for example is only 1mm wider in diameter and 0.5mm narrower in depth. Would it fit into the clip that your battery snaps into?

The last customer who needed a CR2335 for his computer motherboard was able to use a CR2430. He found the extra width was a bit of a squeeze, but that the narrower depth still gave a firm electrical contact.

Or if the larger diameter looks like it might be a problem, use the CR2032. This is 3mm narrower in diameter and 0.3mm narrower in depth.

Have a look at the clip your battery needs to slot into, and decide which is your best bet.

What Battery do I require for my Praktica Camera?

PX21: (see our web page http://www.smallbattery.company.org.uk/sbc_px21.htm)
Praktica LLC,
Praktica DTL3 (DTL-3),
Praktica EE2, EE3 (EE-2, EE-3),
Praktica PLC2, PLC3 (PLC-2/PLC-3),
Praktica VLC, VLC2, VLC3 (VLC-2, VLC-3)

PX28: (see our web page http://www.smallbattery.company.org.uk/sbc_4sr44.htm for a suitable equivalent)
Praktica BX20, BX20S (BX-20, BX-20S),
Praktica BCA,
Praktica BCX,
Praktica BCC,
Praktica BCS,
Praktica BC1, BC3 (BC-1, BC-3),
Praktica BC auto,
Praktica BM,
Praktica BMS,
Praktica B100 (B-100),
Praktica B200 (B-200),
Praktica MTL50 (MTL-50)

PX625: (see our web page http://www.smallbattery.company.org.uk/sbc_mrb625.htm for a suitable equivalent)
Praktica LTL, LTL2, LTL3 (LTL-2, LTL-3),
Praktica MTL, MTL3 (MTL-3),
Praktica MTL5 (MTL-5),
Praktica NOVA B, NOVA II,
Praktica Super TL, TL2, TL3, TL500, TL1000 (TL-2, TL-3, TL-500, TL-1000)

PX675: http://www.smallbattery.company.org.uk/sbc_mrb675.htm
Praktica MTL5B (MTL-5B, MTL-5-B)

No Battery:
Praktica L2 (L-2),
Praktica L3 Endo (L-3)

Do you have a battery for a model 240EE Bell and Howell 16mm movie camera(1958 vintage)?

The Owner's Manual says this beautiful cine camera uses two Mallory PX2 Mercury batteries. There are also occasional references to a Mallory PX4 battery. We can't establish exactly what the PX2 and PX4 were but a former Bell & Howell technician working in a camera shop in Burbank, CA told us the battery was 4.5 Volts which was the clue we needed. You need two of our PX21 4.5 Volt Alkaline batteries batteries to bring you cine camera to life.

What Battery do I require for my Yashica Camera?

PX28A: (see our web page http://www.smallbattery.company.org.uk/sbc_4sr44.htm)
Yashica 35 CCN
Yashica 35 MC
Yashica Atoron
Yashica Electro
Yashica Electro 35 CC
Yashica EZ Matic Electronic
Yashica FR
Yashica FR1
Yashica FR2
Yashica FX-1
Yashica TL Electro (some)

2 x PX640A: (see our web page http://www.smallbattery.company.org.uk/sbc_pc640a.htm)
Yashica TL Electro (most but not all)
Yashica Electro 35 FC
Yashica Electro GX
Yashica Lynx 14-E
Yashica Lynx 5000E

PX32A: (see our web page http://www.smallbattery.company.org.uk/sbc_a32px.htm)
Yashica Electro 35
Yashica Electro 35 G
Yashica Electro 35 GS
Yashica Electro 35 GSN
Yashica Electro 35 GL
Yashica Electro GT
Yashica Electro GTN
Yashica Electro AX
Yashica MG-1
Yashica GL/GT

SR44: (see our web page http://www.smallbattery.company.org.uk/sbc_357.htm)
Yashica 35 ME
Yashica 35 MES
Yashica 35 MF
Yashica 35 MFS
Yashica FFT
Yashica FX-2
Yashica ME-1
Yashica MF

For a more complete list see Yashica's page http://www.yashica.com/support/batterycharts.html

Is it easy to change the 'Non-replaceable' batteries in Polar Transmitters?

In a word - NO. It is definitely not straight forward. Polar transmitters such as the Polar T61 take standard CR2032 batteries, but are in a sealed unit and difficult to access.

WARNING: The following procedure is strictly NOT for the faint-hearted. It will void the warranty on your monitor and may in fact cause irreparable damage to your transmitter. But it worked for me the first try and only took me 30 minutes. Total cost (not counting my time) for crafting a replaceable battery unit from a sealed Polar transmitter: $2.79 plus a couple of wires and some electrical tape I had laying around the house.

Oh yes -- this in no way authorized by Polar Electro Oy (as if you haven't guessed by now).

Materials needed: One CR2032 lithium battery, a soldering iron (preferably of the sort used for fine circuitry work), rosin core solder, a pair of small needle-nose pliers, an X-acto knife or similar tool, a pocket knife, two lengths of fine wire (with connectors of some sort on one end if at all possible, as they're easier to fasten to a battery) and a roll of vinyl electrical tape.

Remove the strap from your HRM transmitter. Lay the transmitter on a hard, flat surface. The back of the transmitter, where it makes contact with your chest, should be down.

Using the X-acto knife, carefully carve away the face of the transmitter in the raised area where the color "Polar" nameplate appears. You may want to carefully pry off the nameplate for later gluing onto the front of your reconditioned monitor. A couple of potential trouble spots: The battery is in the center of the unit -- don't punch through hard there. The transmitter coil is on the bottom or top edge of the case -- don't punch through hard there. Take your time. Cut a large enough hole to work your soldering iron into the case.

Once you've removed the face of the transmitter, mark a plus-sign onto the edge where the positive lead coming off the battery goes into the circuit board.
Grab the positive battery lead (it's flat metal and the only one showing) with the pliers, then carefully melt the solder on the end of the lead that goes into the circuit board and simultaneously pull the lead out of the board. Pull the battery up to a vertical position.

Peel the rubber piece off the bottom of the battery and set the protective piece aside. Repeat Step 4 with the negative terminal of the cell. Dispose of the battery in an environmentally sound manner.

Carefully solder your wires into the holes where you pulled the original leads out.

Secure the ends of the leads (positive to positive, negative to negative) to the new battery with a tight wrapping of electrical tape or a method of your own choosing. Stick the rubber pad you earlier pulled off the original battery to the bottom of the battery. To further protect the battery and reduce the chances of shorting anything out, wrap it in electrical tape.

Tuck the battery and wires into the transmitter case and seal the whole thing with clean, tight spirals of electrical tape. Alternatively, you may want to use some sort of waterproof caulking to seal the case, especially if you swim with your HRM.

Try the transmitter out.

As you can see, there are easier ways of dealing with the dilemma Polar has imposed on its buyers with its sealed transmitters. You can send your unscarred but lifeless transmitter to Polar with $39 for a new sealed unit. Or you can buy a new Cardiosport replaceable battery transmitter and chest strap for $49. But if you're cheap, and adventurous, you can't beat the fun of doing it yourself -- or the perverse pleasure of wearing an HRM transmitter that looks kind of like the car you used to keep running with the help of a large box of tools and a small spool of baling wire.

Why are 3.6V AA cells such a tight squeeze in the VR3?

This only applies to early VR3s that were fitted with a small diameter battery cap. I first hit the problem you describe with my VR3, when I wanted to use the RS battery (RS part No 596-602). This battery has a plastic outer coating, which makes it just a tad thicker than a standard AA cell which are just painted metal . All you have to do is to cut off the bottom 17-18mm (ie from the -ive end) of the plastic coating. The -ive end of the battery fits into the VR3 battery cap which is the -ive terminal, so stripping this bit of plastic off doesn't cause any electrical problems. 

3.6V AA Lithium thionyl chloride batteries from the Small Battery Company don't fit for a similar reason and could easily be rectified in the same way in under a minute with a sharp knife. 

Delta-P Technology (who make the VR3) have been aware of this problem for the last few years. Now all new VR3's are fitted with a mark 2 version of the battery cap, which has a slightly wider diameter hole and will accept these slightly fatter batteries without modification. Delta-P also sell the mk2 battery cap in an upgrade kit with a Lithium 3.6V battery for people who have their older units. 

Regards Geraint.

Thank you Geraint Ffoulkes-Jones for sharing with us the benefit of your experience.

I need a 1.5V Eveready U10 for my AVO meter. Is there a replacement?

STOP PRESS: This battery is currently in stock. Look at our Eveready U10 page.

The Eveready U10 was a Carbon-Zinc battery 13/16 of an inch in diameter and 2 and 5/16 inches in height. In metric units that is 20.6 mm in diameter and 58.7 mm in height. (Take care not to confuse it with the Burgess U10 which is a fifteen [15v] volt battery).

No equivalent to the Eveready U10 is manufactured any longer.

A standard 'C' cell is 22 mm diameter x 42.3 mm. This is too wide for most AVO meters. If this isn't too wide for you fit you might be able to make do with a 'C' cell by finding or making a conducting spacer 16.4 mm in length.

A standard 'AA' is too narrow and too short. It seems to be the best bet. An 'AA' cell and a stack of one pence pieces is often an adequate replacement.

You will need to be inventive. Good luck.

I need a new Tomtom 700 battery. Is there a replacement?

STOP PRESS: This Tomtom battery, fully made up, is currently in stock. It is available here....

Here is the experience of Ed Chapman who very generously offered to answer queries about his procedure. Send in queries to Ed using the 'Contact Us' link on the left.

I bought a LIR-18650-FT to replace the exhausted one in my mate's Tomtom 700 which was five years old and no longer held a charge. The charging circuit is a circular pcb the same size as the battery end, with a little soldering and delicate disassembly it was possible to remove it from the exhausted battery and attach the new battery. I searched high and low for a replacement battery on the web but no-one seems to have spent the time and effort to document or advertise these batteries or how to change them. Tomtom themselves will replace the battery for you but this service is very expensive - Tomtom probably prefer customers to replace the unit entirely! Anyway thanks for a great service and please mention the Tomtom 700 in the battery description so it can be Googled by others. If anyone wants, I will try to help - but bear in mind that I am only familiar with the Tomtom 700 model.

Please advise on the battery required for a Ronson electronic Varaflame cigarette lighter.

We asked our sadly departed and much missed friend Richard Smith, lighter guru at www.strikealight.co.uk.

Richard informed us that there are two models of the Ronson Electronic Varaflame cigarette lighter. The battery you require depends on which model  you have.

The L1 is about 2.5 inches high and can most readily be identified by its marking 'Made in the UK'. It takes the 12.0 Volt LRV08 battery (see .... http://www.smallbattery.company.org.uk/sbc_lrv08.htm).

The L7 is squatter and oval and can most readily be identified by its marking 'Made in France'. It takes the 15.0 Volt A220 battery (see .... http://www.smallbattery.company.org.uk/sbc_a220.htm).

MRB625 and Gossen Lunasix.

The use of the MRB625 WeinCells in the Gossen Lunasix 3 meter can be problematic because the central negative electrical contact of the battery chamber has sprung ‘arms’ which have a span that is greater than the diameter of the negative terminal of the WeinCell. This can result in the cell being short circuited!!!! The original PX625 negative terminal is 11mm whereas the WeinCell MRB625 is only 8mm. By placing a 13mm brass washer over the sprung arms this problem can be solved.

Therefore, for use in the Lunasix 3 Gossen meter (and ONLY the Lunasix 3 - other models are unaffected), the MRB625 WeinCell requires the addition of a 13mm conductive washer. The widely available M6 washer will do the trick.

Can you make the tabbed cell I require?

We stock a good selection of factory made tabbed cells. Look here,,,,,, and here....... for starters and feel free to ask us using the 'Contact Us' link on the left.

But the truthful answer is 'no' - I'm afraid we do not add tabs to order. If that leaves you in a pickle consider this marvellous new product - Wire Glue. Wire Glue utilizes the latest advances in microcarbon technology to bring you a highly conductive glue at a fraction the price of competitive products which use precious metals such as silver. Order a bare, untagged cell from us and then carefully remove the existing tags from your dead cell. Apply the Wire Glue to your cell's surface and to the tag, pop them together and let it all cure overnight. By the morning your problems will be solved. Find out more about Wire Glue here.........

Can you explain "passivation"?

If a lithium thionyl Chloride cell is stored for a couple of years, a microscopic layer of lithium Chloride forms on the lithium anode. This is an insulator and its properties are one of the reasons for the very long shelf life of lithium thionyl Chloride batteries. The resistance of this lithium chloride layer increases the internal resistance of the cell and the effect is called 'passivation'. 

A cell that has been stored for many years might be incapable of delivering high currents or might even give the appearance of having expired. To revive the cell you can briefly short circuit the cell and, in about two or three seconds, the Lithium Chloride layer is 'burned off' and the cell is back to normal. Give the cell a five minite rest afterwards as its voltage will be depressed after this procedure. This recovery process is known as depassivation. 

Depassivation of larger cells such as "D" size cells is a little more tricky as the cells can contain short-circuit protection. You will probably need to put a suitable resistance in series with the cell to limit the current. Another elegant method is to short-circuit the cell through an ammeter. As the passivation layer is burned off, the current will rise. When the current measured approaches the 'maximum continuous current ' recommended in the specification of that cell you can stop the discharge.

Does the Fujica ST701 camera work with H-B Adapter?

No I'm afraid not. The H-B adapter replaces the whole battery compartment lid and the single battery of several Spotmatic cameras. It doesn't work with the different style of lid from the ST701 and the ST701 requirement for two batteries. You will need to use the MRB400.

Is the ZA5 or PR63 still available?

Sadly not. The ZA5 or PR63 battery was a rare and very small hearing aid battery of dimensions Diameter: 5.8 mm. Height: 2.15 mm. Increasing miniaturisation was supposed to make this battery more and more popular, but in fact it became obsolete and production has been discontinued by all the hearing aid battery manufacturers. You’re only option is to see how your device works with a similar sized silver oxide battery - the 379 The voltage is fractionally higher, 1.55v as opposed to 1.4V, and the capacity is significantly lower, so the batteries will last for a shorter period and need changing more often. We’d be very interested to hear about your experiences if you use the 379 as an alternative to the ZA5 battery.

MR-9 Adapter and Leicameter MR.

The use of the MR-9 Adapter in the Leicameter MR and the Leicameter MR-4 can be problematic because the central negative electrical contact of the battery chamber consists of three ‘fingers’. The tip of one of these fingers can slip round the negative contact of the adapter and make contact with the positive side of the adapter to make a short circuit. It is finely balanced and the smallest movement of the adapter/cell can trigger a short circuit.
One solution is to insert a small strip of plastic or similar spacer between the adaptor and the wall of the battery compartment. Insert it just opposite the positive metal strip that goes up the side of the compartment. The inserted plastic strip fixes the the adaptor and prevents any movement.

I am looking for an Eveready 1915. Can you help?

The Eveready 1915 battery was 3V and also known as 2T5, BA6106, K773, T7 and V0003. It is now obsolete but was widely used in torches. It was 9/16 of an inch in diameter and 4 inches in length (14mm diameter, 101mm long) and was internally constructed from two AA sized cells. Two AA batteries taped together into in a stick should do you just fine.

Can you help with other 3V 'Duplex' batteries?

The Eveready No 8 battery was internally constructed from two R10 cells. It is still available - click here.
The obsolete Eveready 1839 battery was 3V and internally constructed from two 'C' sized cells. Two alkaline C batteries taped together into in a stick should do you just fine.
The obsolete Eveready 1829 battery was 3V and internally constructed from two 'D' sized cells. Two alkaline D batteries taped together into in a stick should do you just fine.

Do you have a UCAR 201 or Energizer / Eveready 201 battery for my LIP watch with R27 movement?

LIP of France, in 1958, began selling out one of the earliest electronic watches (many argue it was THE earliest electronic watch) based on their R27 movement. It was powered by two 1.5V carbon-zinc cells that were developed in the previous year by Union Carbide and its subsidiary Eveready. Called the UCAR 201 or Eveready 201, it had a distinctive brass cannister and a pitch seal. Later, a silver oxide version was brought out with a more traditional steel canister. Sadly, neither version is currently manufactured. The size of the 201 was between 11.15 and 11.60 mm in diameter and between 3.05 and 3.39 mm in thickness. Fortunately there is a modern cell that is similarly sized, the 350 or SR1136W silver oxide cell and, with diameter of 11.6 mm and height of 3.6 mm, it works well in LIP R27 based watches. The UCAR / Eveready 201 was also used in some Hamilton 500 watches and some Epperlein 100 watches and some very early Seiko electronic watches and in these cases too, the 350 is a suitable alternative. So we suggest you get yourself a couple of 350 cells from here...........

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