View Single Post
  #5   Report Post  
Posted to sci.electronics.basics,alt.electronics
Thomas G. Marshall Thomas G. Marshall is offline
external usenet poster
 
Posts: 138
Default Mismatched voltage wired in parallel. What is resulting voltage?

John Popelish said something like:
Thomas G. Marshall wrote:
Fundamental questions.

Given:

If I wire two 3V 1mA batteries in parallel, the result is 3V 2mA.

If I wire two 3V 1mA batteries in series, the result is 6V 1mA.


Batteries are not rated for current, but with current times
time, e.g. mA H for milliampere times hour.


Ok, fair enough.


BUT:

1. What happens if I wire the following in parallel:

3V 1mA
6V 1mA


The higher voltage battery runs down very quickly, trying to
charge the lower voltage battery. The exact process depends
on whether this causes either of the batteries to be
permanently damaged or not.

2. And similarly, the following in series:

3V 1mA
3V 2mA


If those are milliampere hour ratings, then you get a 6 volt
battery for the first milliampere hour output, then you get
a much lower voltage as the larger battery tires to reverse
charge the smaller battery with whatever load the remaining
voltage drives through the load.

Does #1 above average the voltage to 4.5V?


Almost certainly, no.

Does #2 above average the current to 1.5mA?


No.


Fair enough.....thanks! Too bad, in addition to two very clear, educating,
and friendly replies, there had to be a rude idiot. After 5000 posts in
usenet, I'm used to seeing all forms of foolishness, but it still amazes me
a little.