clock battery

[laurence]

All,
I have a march '67 Mk1 saloon,post mb60000, and note in the handbook that the clock requires a 'hearing aid' battery,- does anyone have any idea where such a battery or its modern day equivalent can be obtained?,
thanks in advance,
Laurence

[Mike Stevens]

Hi Laurence,

It was originally a 1.35V Mercury battery. These are no longer available but there is a possibility of using a standard 1.5V cell. I believe that it makes the clock run a bit fast and I did help out Wild Bill (I think!) some years ago with some suitable resistor values to reduce the voltage. Maybe he can remember better than I can!

Cheers,
Mike.

[rlubikey]

Yes, mercury cells have a very flat discharge voltage during their working life, so the "crude" timepiece of the day could still give reasonable accuracy. Unfortunately, mercury's pretty much banned now by legislators (they must be mad as Hatters!) so your choice is either an alkaline cell, which will run fast at first then get gradually slower and slower and slower (what time is it, Eccles?) or some sort of clever little regulator circuit running off the main battery (watch out for minimum output current!).

A quick look at fleabay shows some "Wein Cell 1.35v mercury replacement camera batteries". I have no idea if these would suffice. Worth a try??

Richard

[wild bill]

Hi Mike,what I found when I got the supply voltage down to 1.35v,it would run the clock,but would not start it! For a while I did have a "kick" of 1.5 to start,then dropped it to 1.35.Now I just run it off a pack of 4-AAA batteries in a cage in parallel! I just set the time whenever I'm in the car,never late for appointments!!
Hope all is well,Bill.

[tony]

(what time is it, Eccles?) not quite, " What does your clock say Eccles....tick tock."
Don't know about Mk1's but I've yet to find a Mk2 clock that works like it should. Replaced mine with an oil pressure gauge.
Tony.

[kevinw]

The clock in my MK2 is accurate if the car is used every day, but if the car is left unused in the garage, it will loose a few minutes a day. But not always. I just put it right when I use the car.
As we're onto Goon Show quotes, here's my favourite:

Seagoon: "Hello, Eccles, what are you doing here?"
Eccles: "Well, everyone's got to be somewhere, haven't they?"

Very profound...

Kevin

[Charles H]

You've been a very naughty boy

[laurence]

Thanks for all suggestions and pointers, much appreciated, as always,
cheers,
Laurence

[Mike Stevens]

Eccles: "Well, everyone's got to be somewhere, haven't they?"

And oft repeated in such things as the Beiderbecke Affair/Tapes/Connection.

As you say, very profound.

Yes, we're all well Bill, hope you are too. Just awaiting the arrival of our first Grandchild. This just isn't possible - I'm far to young to be a Grandad. The idea of sleeping with Grandma is also interesting....

It should be possible to design a 1.35V supply down from the battery, but as stated, the issue could be the quiescent current being a bit high!

Cheers,
Mike.

[rlubikey]

... an alkaline cell, which will run fast at first then get gradually slower and slower and slower (what time is it, Eccles?)

Eccles: I've got it written down on this piece of paper ...

You remember, the time was correct twice a day. I was thinking that, as the alkaline cell ran down, it would eventually keep the right time ... but only for a while! ... and you wouldn't know when!