What happens when we connect 2 batteries + with +, - with -?

In summary, connecting batteries with their + and - poles does not cause any change in potential difference, assuming they have the same voltage. However, if connected in reverse, they may quickly drain and overheat. The resulting battery pair has the same volts but double the amp and amp-hour capacity. However, this does not necessarily mean that a lightbulb would shine brighter when connected to the new battery, as the potential difference remains the same. The question of how much greater the amp capacity is remains unanswered.
  • #1
CasterlyRock
6
0

Homework Statement


Batteries are connected together with their + and - poles.

Homework Equations



The Attempt at a Solution


I quess that nothing happens because there is no change in potential difference.
 
Last edited:
Physics news on Phys.org
  • #2
Exactly. Assuming of course that the two batteries do have the same voltage, nothing will happen. (If you connect them + to - and - to +, the two batteries will quickly drain and the wires connecting them may over heat. Not a good thing to do!)
 
  • #3
CasterlyRock said:
I quess that nothing happens because there is no voltage difference.
Sounds reasonable. Are you possibly also supposed to make an observation about the properties of the resulting battery pair?
 
  • #4
No, it only says that batteries are the same.
 
  • #5
CasterlyRock said:
No, it only says that batteries are the same.
I meant properties of the pair after connection compared to a single battery. Volts? Amps? Amp-hour capacity?
 
  • #6
insightful said:
I meant properties of the pair after connection compared to a single battery. Volts? Amps? Amp-hour capacity?
Really nothing except what I wrote. The question has a conceptual nature. I assumed that when connected, batteries are in parallel, that means the same potential as it was, so nothing changes.
 
  • #7
Could you not say that you produced a "new" battery with the same volts, but twice the amp and amp-hour capacity?
 
  • #8
insightful said:
Could you not say that you produced a "new" battery with the same volts, but twice the amp and amp-hour capacity?
I don't understand. Do you mean if I would apply a resistor to that new one battery (lets say a resistor is a lightbulb) it would shine brighter than one applied to the original battery?
 
  • #9
CasterlyRock said:
I don't understand. Do you mean if I would apply a resistor to that new one battery (lets say a resistor is a lightbulb) it would shine brighter than one applied to the original battery?
Why would it shine brighter with the same volts applied?
 
  • #10
P=I^2*R. You've said that amp is greater than before.
 
  • #11
CasterlyRock said:
P=I^2*R. You've said that amp is greater than before.
No, I said the amp capacity is greater than before. How much greater?
 

1. What is the purpose of connecting two batteries + with +, - with -?

The purpose of connecting two batteries + with +, - with - is to increase the voltage output. When connected in series, the voltage of the two batteries adds up, resulting in a higher voltage output.

2. Will connecting two batteries + with +, - with - increase the battery life?

No, connecting two batteries + with +, - with - will not increase the battery life. The battery life is determined by the capacity of the individual batteries and connecting them in series does not change this.

3. Is it safe to connect two batteries + with +, - with -?

Yes, it is safe to connect two batteries + with +, - with -. However, it is important to make sure the batteries have the same voltage and are connected properly to avoid any short circuits or damage to the batteries.

4. Can I connect more than two batteries + with +, - with -?

Yes, you can connect more than two batteries + with +, - with -. The voltage output will increase with each additional battery added in series.

5. What happens if I connect two batteries + with +, - with - and they have different voltages?

If you connect two batteries + with +, - with - and they have different voltages, the battery with the higher voltage will discharge into the battery with the lower voltage. This can cause damage to the batteries and should be avoided.

Similar threads

  • Introductory Physics Homework Help
Replies
3
Views
250
  • Introductory Physics Homework Help
Replies
4
Views
262
  • Introductory Physics Homework Help
Replies
5
Views
903
  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
9
Views
1K
  • Introductory Physics Homework Help
Replies
7
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
934
  • Introductory Physics Homework Help
Replies
8
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
910
  • Introductory Physics Homework Help
Replies
5
Views
1K
Back
Top