Hello

I've been using LR44's in the camera and swapping them out if there's a long stretch between shoots or if I've done 10-15 rolls in one session.

I'm prep'ing my DLSR rig to shoot video tonight and the compact YOGA mike takes SR44's which I didn't know even existed. Exactly the same size.

So what are peoples preferences?

I keep the LR44s and use them elsewhere so there's no real wastage.

Cheers

M

On 1/16/2011 11:10 PM, Mark wrote:

> Hello
>
> I've been using LR44's in the camera and swapping them out if there's
> a long stretch between shoots or if I've done 10-15 rolls in one
> session.
>
> I'm prep'ing my DLSR rig to shoot video tonight and the compact YOGA
> mike takes SR44's which I didn't know even existed. Exactly the same
> size.
>
> So what are peoples preferences?

The LR is an Alkaline battery, while the SR is a silver oxide battery.
The Alkaline is less expensive and smaller capacity. The Silver has a
higher starting voltage and a flatter discharge curve.

I find the Eveready site to have reasonable reference documents. Trouble
is, they don't seem to make an LR44. The datasheet for the SR44 is:
http://data.energizer.com/PDFs/344-350.pdf
Look at that voltage curve! At a low (.2ma) draw, that thing is flat,
flat, flat for almost 500 hours. At freezing (0c) it has about 75% of
the nominal capacity.

Duracell offers an LR44, but present their product information a little
differently.
http://www.professional.duracell.com/product_data/datasheets/LR44.pdf
Their curves don't look as nice. The voltage drops faster and sharper.
But, you have to consider that they are presenting the curve for a
1.25ma current draw. So this is a bit of apples and oranges comparison.

Back in December of 2006, I measured my TL120's current draw:
http://tech.groups.yahoo.com/group/MF3D-group/message/301

> My measurements (taken with my 25 year old analog VOM) indicate the
> following currents: meter active 5ma shutter open 25ma

Please notice that these current draws are _way_ higher than any
suggested on those data sheets. Please also consider that the TL120 of
2006 is probably very different from that of 2010.

There are also several threads in the archives relating to power draw
and different battery chemistry as it relates to the TL120
http://tech.groups.yahoo.com/group/MF3D-group/message/2489
http://tech.groups.yahoo.com/group/MF3D-group/message/485

John Thurston
Juneau, Alaska