Difference between a step down and a step up

Your first question...

A step down (power supply?) steps down the input voltage.

A step up steps up the input voltage.....

They are different functions.

As for the question about how you measure the life of a mobile battery, the easiest and cheapest method is to see how long they last when power is drawn at a constant rate... the one that lasts longest is better.... Unless you want a low capacity battery then the one that lasts shortest is better....???

John.

A step down decreases altitude whereas a step up increases altitude

Talking staircase,: Usually 180º.

Talking transformers,: Is the output higher or lower than the input. UP = step up DOWN = step down

Your question is like asking, "What is the difference between Ms. and MRs.?" The answer is of course , Mr.

The answer to question #2 is: Type of battery, ambient temp. amount of charge ,and blah blah blah.

Wangito.

if you don't know the answer then plz don't answer.

If after all the answers you got, and not only from me, you still don't understand, than you never will.

I know the answer and gave it to you, And now I am sorry I have wasted my time doing so...

And BTW, Who are you to tell me if to answer or not?

Wangito.

....and he is only logged on as a despised "Guest", well said Wangito, I agree with your comment fully.

In the meantime I basically do not heed anyone who logs on as a Guest, their input is rarely worth bothering with, with few exceptions.....

Hallelujah! and Amen.

Wangito.

And no more guestcom.

A step down is a demotion (bad news) whereas a step up is a promotion (good news).

PW..... there is no i in team but there is a me!

There is also a u in bull as well as an i in sh*t....

John.

When the original info is too vague, don't we have fun taking the Mick on CR4!!!!

Ahhh you've got to have a laugh now and then haven't you Andy?!!

I agree completely! Life is short enough as it is without making it tedious as well!!

The basic determiner of lifespan of a cell phone battery is the number of charge/discharge cycles it goes through. After so many cycles (number depends on battery type) the battery tends to deteriorate and eventually no longer functions. Panasonics has a good CD on bettery types, but I don't have a web site handy.

Bill