[taoster]

ive been listening to my porta corda with my newly built altoid battery pack. the battery pack consists of three 9V batteries with a toggle to switch between 2 or 3 battery mode.

While listening ive noticed a few things:

1. three 9V batteries in series does not seem to extend the battery life very much. I am guessing the power/voltage drain is still equal but with the total output voltage being higher thus squeezing more juice out of an battery.

2. when a battery is drained, it becomes a resistive load on the other batteries! When i have a flat battery connected, it sounds better removed than leaving it in place.

Questions:

1. In real life, are all 3 batteries drained equally in series?

2. by placing batteries in parallel, could the battery life be increased?

thanks

 

[blip]

I'm pretty sure that if you put two batteries in parallel they will last twice as long.

 

[Dreamslacker]

Quote:

Originally posted by taoster ive been listening to my porta corda with my newly built altoid battery pack. the battery pack consists of three 9V batteries with a toggle to switch between 2 or 3 battery mode. While listening ive noticed a few things: 1. three 9V batteries in series does not seem to extend the battery life very much. I am guessing the power/voltage drain is still equal but with the total output voltage being higher thus squeezing more juice out of an battery. 2. when a battery is drained, it becomes a resistive load on the other batteries! When i have a flat battery connected, it sounds better removed than leaving it in place. Questions: 1. In real life, are all 3 batteries drained equally in series? 2. by placing batteries in parallel, could the battery life be increased? thanks

Placing batteries in parallel increases the current output (if needed) and shares the load between the 3 batteries. This extends the run time of your amp.

Placing the 3 batteries in series increases the voltage across. This is useful if your opamps need more voltage to perform. It doesn't increase runtime.

In real life, the 3 batteries aren't exactly drained equally. This is a problem with rechargable battery packs. Not all the batteries are drained when you need to recharge.

 

[taoster]

Quote:

Originally posted by Dreamslacker In real life, the 3 batteries aren't exactly drained equally. This is a problem with rechargable battery packs. Not all the batteries are drained when you need to recharge.

Ive noticed this but i wasnt sure if it was the fault of the battery or the configuration. If each battery is not drained equally than the each battery must have an internal resistance that differs?

considering this, i should of made the 3-way switch to be off/in series/in parallel instead of off/2battery/3battery in series.

For batteries setup in parallel, can anything be used to stablise drain?

 

[Dreamslacker]

Quote:

Originally posted by taoster Ive noticed this but i wasnt sure if it was the fault of the battery or the configuration. If each battery is not drained equally than the each battery must have an internal resistance that differs? considering this, i should of made the 3-way switch to be off/in series/in parallel instead of off/2battery/3battery in series. For batteries setup in parallel, can anything be used to stablise drain?

This isn't much of a problem if you charge the individual batteries seperately. In battery packs where the entire pack is charged at one go, it's a problem since some cells will suffer from memory effect first.
You can discharge and charge each battery (a 8.4v/9.6v consists of multiple cells) manually though. Don't worry too much about it.