Battery Charger 12 volt

[JPINDA]

Thanks for the help.
I am designing a machine with a touch screen and a PLC.
There are 3 24 volt motor and 2 12 volt motors.
I would like to run the unit on 6 gel cel batteries.
The question is I need to have a "Fuel Gage" and/or a charger than can talk to the plc.

Later JeReMy

 

[logbook]

>The question is I need to have a "Fuel Gage" and/or a charger than can talk to the plc.

Strictly speaking that is not a question.

If you could spend a few minutes writing down what you need then you may get some appropriate help. For example you would like to run the unit on 6 gel cel batteries. Why 6? What voltage, 2V or 12V? There is just far too little information presented.

 

[JPINDA]

Sorry about that.
I didn't want to sent the post like that,
I got called away from by desk any way.

I have 6 gel cells at 12 v each for a 24v system.
How do I get the PLC to "read" the voltage like a fuel gage.

Later JeReMy

 

[itsmoked]

Can you measure voltages with your PLC?

If so, What voltages will it measure?

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[IRstuff]

1. Your PLC would need an A/D to "read" anything at all.
2. Voltage is not a direct indicator of remaining capacity, so you need to consult the battery supplier and get the data from them
3. You need to write the software to convert voltage into capacity and then write the software to display the data in a "fuel gauge" format.

TTFN

FAQ731-376

 

[itsmoked]

Don't forget you WILL need to read the battery temperature also. Another voltage in.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[logbook]

Depends what you mean by a PLC. If you use an ADC with an SPI interface, would your PLC have enough gates to handle it? This is perhaps more FPGA territory, but perhaps that is covered by your term "PLC".

The gauge could be done in firmware (VHDL) or software, depending on your overall system design. Cell voltage depends on three things:
1) cell charge state
2) temperature
3) load current being drawn

If the load current is variable then you would need to measure the load current as well as the cell's terminal voltage in order to estimate the remaining cell capacity.

 

[itsmoked]

log; I think we are talking facility. Not circuit board design. (never know though)

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[ssn596]

Am curious as to what this system is going to do and where you are going to use it. Is this some portable piece of equipment. If so why use motors of two different voltages? Lot simpler wouold be to stay with 12 or 24 DC for all motors. Should make it easier to select a battery charger also. Another thought is if you are transporting in a car or truck if 12 VDC you can just parallel with vehicle electrical to charge batteries while driving HOWEVER in this case you would be better off with standard lead acid wet cells which have the same charge characteristic as the battery in the vehicle.

Dan Bentler