Battery power

[schick]

Allright... I am need some suggestions...
I have to come up with a self powered test rig with enough juice to control an AB Control Logix PLC, (4 modules), 3 electromagnetic flow meters, and a bank of 4 solenoids, and a wireless ethernet point.

my initial thought was to put a couple of motorcycle batteries into the box and strap them down. but that's kind of heavy and can get ugly quickly inside a metal box. aside from the PLC everything else is 24 VDC.

HELP! It's Friday and I'm losing my hair over this....

Just call me cue ball.

 

[Musician]

It might help to know how much current you are using. You can set this system up using a variable DC power supply and measure the current used. This with the length of time the unit will be in use at any given time will give some insight to the amount of available power needed. The first thing that comes to mind is NMH AA cells. That is what is used in some laptop computers.

 

[Skogsgurra]

Yes, I would also look at NiMH batteries. You get a lot of energy in a small (and relatively expensive) package. They do not leak and you can charge them in an hour or less.

Your equipment seems to be a combination of several devices with two different supply voltages. It could be wise to provide two different sets of batteries; one for the PLC (unknown voltage) and one 24 V for the other circuitry.

The first question to ask is: For how long shall this system work on batteries? That decides how much battery you need. If the answer is "several weeks or months", you have to find another solution. A small genset perhaps. And if it is very important that it works all the time, you should back the genset up with batteries and provide an alarm channel in the communication so that someone can fill up the tank or restart the genset if it goes down.