1. ## watch battery stack?????

can I stack watch batteries small ones, the size just a bit bigger then emag magnets, to get 9v?
if so how many would it take?
and how long will they last?

thankyou,
KNM.

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each battery cell is 1.5 volts, so to reach 9v you need 6

3. Batteries are rated in milliamp-hours, or current x time. Wikipedia says 150 mAh for an alkaline 1.5 lr44 battery. In a series stack of 6, you will get 150 mAh of 9 volts, which is 150 milliamps for one hour. Regular 9 volts are around 550 mAh, so your stack will last about 1/3 to 1/4 of a 9 volt, depending on how fancy your batteries are.

It makes sense when you look at the physical volume taken up by the stack.

4. Originally Posted by Spider-TW
Batteries are rated in milliamp-hours, or current x time. Wikipedia says 150 mAh for an alkaline 1.5 lr44 battery. In a series stack of 6, you will get 150 mAh of 9 volts, which is 150 milliamps for one hour. Regular 9 volts are around 550 mAh, so your stack will last about 1/3 to 1/4 of a 9 volt, depending on how fancy your batteries are.

It makes sense when you look at the physical volume taken up by the stack.
anyone know where I can get watch in the 1000 mah range?
I knew all this other stuff, my bad.
thinking for a setup need the space and if I don't have the space I can print a battery holder that wont look crazy
does that help?

sorry I should have asked for a source where to find them.
.

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You won't find a watch battery in the 1000mAh range. Watches just don't have need for that kind of long term requirement and the small size doesn't have the volume to store that kind of capacity.

The other problem you will run into when using watch batteries, is the demand current capability. They don't have a high C rating, so don't expect them to be able to deliver any amount of instantaneous current output to any load.

6. Originally Posted by athomas
You won't find a watch battery in the 1000mAh range. Watches just don't have need for that kind of long term requirement and the small size doesn't have the volume to store that kind of capacity.

The other problem you will run into when using watch batteries, is the demand current capability. They don't have a high C rating, so don't expect them to be able to deliver any amount of instantaneous current output to any load.
ok so next question is what is the best way to make a good 9v
with go c rating but half the size of current 9 v?
without producing my own battery.

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You need to know exactly what is the worst case on-demand current you will be drawing from the battery. Then you need to know the how much capacity you need. The mah capacity will be lower at a higher current draw due to heating. Once you have the capacity and current values, you can figure out the minimum cell type you need. Lithium type batteries have high energy densities so they tend to be smaller cells than other batteries of similar capacity.

8. Originally Posted by athomas
You need to know exactly what is the worst case on-demand current you will be drawing from the battery. Then you need to know the how much capacity you need. The mah capacity will be lower at a higher current draw due to heating. Once you have the capacity and current values, you can figure out the minimum cell type you need. Lithium type batteries have high energy densities so they tend to be smaller cells than other batteries of similar capacity.
got it,
found what I need.

thankyou,
KNM.

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You can also use 3v batteries. I made a epneu years ago with 3 batteries in the foregrip.

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