In the last video, we talked about series
in parallel and color coding our circuits,

so that we were able to
see series in parallel.

Now, let me show you how we actually
do that in a battery charging circuit.

This is useful if you have a motor home,
okay?

Here are two batteries, for example.

Let's decide if they're in series or
parallel.

Right here, let's color code our circuit.

So here's one.

Is that an extraordinary or
an ordinary node?

That's an ordinary node.

Here's another ordinary node.

And finally, one more ordinary.

Okay, so I have three ordinary nodes.

I have two batteries that
are connected by one color.

And so they are in series.

12 volts is in series
with the other 12 volts.

So the total voltage that I have is
12 volts in series with 12 volts or

24 volts from top to bottom.

Now, I would connect my
batteries up just like this.

See if I two car batteries, for
example and I wanted to hook them up.

I would literally take the positive
arm of one battery that would

come out to the top of my 24 volts.

I would take the negative terminal of one
battery and connect it to the positive

terminal of the other, and I'd take
the negative terminal of that battery,

and connect it up, and
I would end up with a 24-volt battery.

Now, let's also talk about the current.

Let's say that this battery is
capable of delivering 20 amp hours.

Well, I I would now have two batteries.

Both capable of delivering 20-amp hours,
but they would have 24 volts.

So they still would be a 24 volt,
20-amp hour battery.

Now, let's go to the parallel connection.

Here I have two 12-volt batteries and
let's color-code them, and

see if they really are in parallel.

So here is one.

Is that an ordinary or
an extraordinary node?

That's an extraordinary node.

And right here, ordinary or extraordinary.

That's an extra ordinary node, okay?

Well, in my parallel connection,
I can see that they are parallel,

because they share the two colors,
red and yellow.

And remember that if I
have a parallel circuit,

the voltage stays the same,
but what does change?

Okay, so I hook them up this way.

I will connect both positive terminals
together and that will come out to here,

and the negative terminals
will come out there.

What happens is my voltage the same,
but I can get more current.

So instead of having the 20-amp hour
system, I have a 40-amp hour system.

So let's go back and take a look.

Here I have my batteries in series,
I doubled my voltage.

Here I have my batteries in parallel,
I'm doubling my current.

Now, here some other combinations.

Let's see what's in
series in parallel here.

Okay, there is one ordinary or
extraordinary node.

Yep, ordinary node.

Here is ordinary or extraordinary.

That's extraordinary.

Here is another extraordinary node and

I still have one more ordinary
node right there in middle.

Okay, this is how the batteries would
be hooked up just like in this picture.

All right, what do I have here?

I have two batteries right there.

They're in series, they share one color.

12 volts in series with 12 volts and

I have another 12 volts in series
with 12 volts right there.

And they are in, sorry,
oops, that's not series.

They are in parallel.

So I have 12 volts in series
with 12 volts, which is 24 and

that is parallel with
another 24-volt battery.

The combination of these gave me both
double voltage and double current.

Now, let's see another way
we might hook that up.

Right here,
we could hook up kind of the same thing.

It sort of looks like it might
be the same, let's check it out.

Okay, right there,
all of those connect up together.

How is this different
than my previous case?

The only thing that's different is
that I am connecting my batteries up

by putting two in parallel like this and
another two in parallel and

then connecting those in series.

So it's like having two parallel
connections in series Instead of two

series connections in parallel.

Do I still get the same thing?

Well, let's see.

So right here, I had a 12-volt
system that was 20-amp hour and

another 12-volt system
that was 20-amp hour.

Sorry, what do I have right here?

I have a 12-volt system,
but it is 40 amp hour and

I have another 12-volt system
that is 40 amp hour and

I put the 2 of those together and

the 12 volts in series
are going to give me 24 volts.

Now, let's talk about charging batteries.

I have a 12-volt battery charger and

I reconnect up like this in order
to charge my 12-volt battery.

If I wanted to charge my 24-volt system
with my 12-volt battery chargers,

what would I do?

I will connect the first battery charger
here and the second battery charger there.

If I wanted to pick my system this way,

I would be connecting at
12-volt charger here.

Another 12 the bottom part of the 12
volt charger there, here and here.

So in conclusion, the things that
we talked about today are voltage,

current and resistance.

Variable resistors and resistive sensors.

Measuring voltage currents and resistance.

Series and parallel elements.

Node, paths and loops.

We'll be talking about these
again throughout the semester.

Did you wonder where the picture
was from the front slide?

That's from Peekaboo Slot Canyon
near Kanab, Utah.

Thank you for joining me today.