When do batteries drain more quickly?

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    Batteries
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Discussion Overview

The discussion revolves around the factors influencing battery drain when connected to multiple bulbs in parallel. Participants explore the relationship between the number of bulbs, current draw, and battery performance, touching on concepts such as resistance and power consumption.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions whether connecting more bulbs in parallel requires the battery to do extra work or if energy is simply distributed among the bulbs.
  • Another participant asserts that adding more bulbs increases the current drawn from the battery, leading to faster drain.
  • A participant reflects on the relationship between current and resistance, suggesting that current increases due to decreased resistance in parallel connections, not because of increased voltage from the battery.
  • There is a claim that the battery drains faster because it has to supply more current as more bulbs are added.
  • One participant summarizes that adding more bulbs makes the battery do extra work, which contributes to faster drainage, while also noting that voltage does not cause the battery to drain.
  • A later reply discusses the relationship between constant voltage and power consumption, indicating that increased current leads to higher power requirements from the battery.

Areas of Agreement / Disagreement

Participants generally agree that adding more bulbs increases current draw and leads to faster battery drain. However, there is some debate regarding the mechanisms behind this, particularly the roles of resistance and voltage.

Contextual Notes

Some participants reference Ohm's Law and the maximum power transfer theorem, indicating that there may be additional complexities regarding load matching and internal resistance of batteries that are not fully resolved in the discussion.

hasankamal007
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Will a battery (for eg AA 1.5V) drain out faster when connected to 5 similar bulbs in parallel as compared to only 2 bulbs in parallel?

What I really want to know is that when we connect MORE bulbs parallel to a battery, does the battery have to do some extra work for managing more number of bulbs OR is it that the battery does the same work and that energy is simply distributed among the bulbs?

Thanks in advance.
 
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as you put more bulbs in parallel, the battery has to supply more current, thus drains faster
 
phinds thanks for replying!
But isn't it true that current increases simply because resistance becomes less? Battery doesn't increase it's voltage, it's the resistance that decreases in parallel connection ?
I don't disagree with your answer (infact I thought that is what's true).
It's just another thought.
 
hasankamal007 said:
phinds thanks for replying!
But isn't it true that current increases simply because resistance becomes less? Battery doesn't increase it's voltage, it's the resistance that decreases in parallel connection ?
I don't disagree with your answer (infact I thought that is what's true).
It's just another thought.

Yes, that's correct. That's why the battery drains more quickly. Do you have some belief that it is the voltage that causes the battery to drain? If that were the case, it would drain just sitting there with no load.
 
Yep, that's what I thought. Can you elaborate more on this topic?
 
Last edited:
hasankamal007 said:
Yep, that's what I thought. Can you elaborate more on this topic?

just study Ohm's Law
 
So are these right?
"Adding more bulbs/resistors to a battery, makes the battery do extra work. Hence, becoming prone to drain faster."
"Voltage doesn't cause the battery to drain."
"And that's why electricity-gen companies charge us more if we keep adding more bulbs and appliances in our homes even though voltage is always 220V. (Country wise)"
 
You can consider that the battery voltage remains about constant while the power delivered and consumed is about P = IE...that's one way to start. If the voltage E is about constant, then anything you do that increases the current I increases the power consumed and requires more power from the supply. This ignores the resistance of the source.

Some finer points are discussed here:
http://en.wikipedia.org/wiki/Maximum_power_transfer_theorem

In a practical situation you can help match load to resistance of a battery source depending on what you want to accomplish...see the above article: An AGM battery, for example, has a lot less internal resistance than a wet cell lead acid battery.
 

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