[Vedder323]

Hi... doing my first CMOY with 2x9 volts. Someone asked me if I was doing series or parallel and I didnt know. So, what is the difference and how does it effect the amp?

With my CMOY... I just connected both battery clips to the same joints.

Thanks guys!

 

[flecom]

if you connected both +'s and both -'s together on the batteries they would be wired in parallel, which will give you more 2x the mA of one battery @ 9v

in series it would be + - tied from one battery and then the left over + and - go to the amp you get 18v at the mA of one battery

 

[Vedder323]

Quote:

Originally Posted by flecom if you connected both +'s and both -'s together on the batteries they would be wired in parallel, which will give you more 2x the mA of one battery @ 9v in series it would be + - tied from one battery and then the left over + and - go to the amp you get 18v at the mA of one battery

any advantage with one over the other?

 

[flecom]

well some opamps like more voltage, soooo people usually use series... not sure of any particular advantage to parallel except i would suppose that you would have a slower voltage drop from 9v as the batteries go down perhaps?

 

[JohnFerrier]

 

[silvervarg]

As stated above it seems that the only reason to use 2x9V in series is if you want louder volume.

A follow up question that I hope someone can answer:
Will any of these setups differ in sound quality to a single 9V battery?

Why would you consider having 2x9V in parallell when you could go with 6*1.5V AA and get lots of more mAH?
The difference in size and weight is not that big.
Perhaps 6*1.5V AAA is a valid option as well.
After all a 9V battery is just a compact way of putting 6*AAAA batteries together.

 

[jnewman]

Quote:

Originally Posted by silvervarg As stated above it seems that the only reason to use 2x9V in series is if you want louder volume. A follow up question that I hope someone can answer: Will any of these setups differ in sound quality to a single 9V battery? Why would you consider having 2x9V in parallell when you could go with 6*1.5V AA and get lots of more mAH? The difference in size and weight is not that big. Perhaps 6*1.5V AAA is a valid option as well. After all a 9V battery is just a compact way of putting 6*AAAA batteries together.

Sometimes two 9V's in series sound better because there's better voltage swing and more voltage to work with. Two in parallel shouldn't change the sound and people rarely do it as it's not any different from just storing a spare battery in the case. 6 AA's are considerably larger than 2x9V, and 6 AAA's (in series) actually have a slightly lower mAH rating than 2x9V.

 

[Vedder323]

would someone mind hooking me up with instructions on how to wire in series? I am intrested in doing it like this...

Thanks!

 

[JohnFerrier]

 

[jnewman]

Quote:

Originally Posted by Vedder323 would someone mind hooking me up with instructions on how to wire in series? I am intrested in doing it like this... Thanks!

If you're hooking up in series, you connect the + of one battery to the - of the other.

This way, if you start at one side with a voltage of 0, you get +9 volts to 9 volts, then +9 volts to 18 volts. However, any current flows through both batteries - so there's the total current capacity of one battery.

In parallel, the -'s are connected and the +'s are connected. This way, whichever battery you go through, there's only +9V, to 9V - but current flows separately through each battery, so you get double the current capacity.

 

[ChickenScrtchBoy]

Quote:

Originally Posted by JohnFerrier

Hmm, how would this effect the amp-hours?
I assume that putting them in series would mean that the AH would be multiplied by, then devided by the # of batteries... IE no change...

 

[jnewman]

Quote:

Originally Posted by ChickenScrtchBoy Hmm, how would this effect the amp-hours? I assume that putting them in series would mean that the AH would be multiplied by, then devided by the # of batteries... IE no change...

In series, if the amp is drawing 1 amp, then 1 amp of current goes through each battery - so 1AH batteries will drain in an hour.

In parallel, if the amp is drawing 1 amp, then each battery has 1/2 amp of current - so 1AH batteries will drain in two hours.

 

[mjw]

Quote:

In parallel, the -'s are connected and the +'s are connected. This way, whichever battery you go through, there's only +9V, to 9V - but current flows separately through each battery, so you get double the current capacity.

That's only true in theory. In reality no 2 batteries are exactly the same: The inner impedance of the batteries usually differs slightly which will lead to the effect that the battery with the higher impedance discharges the battery with the lower impedance. So 2 batteries in parallel will not last twice as long as a single battery.

 

[jnewman]

Quote:

Originally Posted by mjw That's only true in theory. In reality no 2 batteries are exactly the same: The inner impedance of the batteries usually differs slightly which will lead to the effect that the battery with the higher impedance discharges the battery with the lower impedance. So 2 batteries in parallel will not last twice as long as a single battery.

It's close enough that it doesn't really matter when describing the difference between series and parallel.