DIY Electric Car Forums banner

1 - 2 of 2 Posts

·
Registered
Joined
·
70 Posts
Discussion Starter #1
I was wondering how a lead acid battery would be modeled in a circuit
simulator. Like most things, I guess it has some resistance, capacitance and
inductance. Of course its characteristics change as it is charged. I would
think basically it is a big resistor that increases in value as it is
charged.

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 

·
Registered
Joined
·
70 Posts
Discussion Starter #2
Hello Al,

I using MultiSims by Electronics Workbench, that you can lay down a a
simulated battery which you can program a certain percentage of over or
under voltage while at no load.

As it is connected to a constant load or a variable load, it will maintain
these voltages while the ampere can vary from 0 to any ampere which depends
on the load of device you want to power.

Connecting a DC power supply to the battery to act as charger, you have to
program the maximum over voltage at the 100% charge battery voltage. For
example, my batteries in my EV is a 180 battery pack, and the 100% charge
voltage at rest is about 192 volts, so that's what the DC power supply is
set at.

If I leave the DC power supply connected as a float charger, then it will
maintain a constant 192 volts while connected to the circuit. If the power
supply is remove, the battery voltage will drop to the minimum voltage in a
certain amount of time you program in.

Current limiting devices are install, such as a circuit breaker, overload
relays or fuses. You can keep adding loads to the circuits until these is a
overload or interrupting loads such as motors and transformers will start to
go to or over the design load of the circuit. You then have to determine the
amount of service factor you have to design into these circuits that may be
from 100 to 200 percent of the rating of the circuit design.

Roland






----- Original Message -----
From: "Al" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Saturday, October 13, 2007 9:41 PM
Subject: [EVDL] battery modeling


> I was wondering how a lead acid battery would be modeled in a circuit
> simulator. Like most things, I guess it has some resistance, capacitance
> and
> inductance. Of course its characteristics change as it is charged. I would
> think basically it is a big resistor that increases in value as it is
> charged.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 
1 - 2 of 2 Posts
Top