Battery Gauge?

**briderx** · 09-06-2007, 01:32 AM

I'm having issues..

I keep killing the battery on my car while sitting in my driveway trying to get my computer loaded and working right. I know that I can plug in an external PSU (which I have done). But in order for me to get everything working correctly, I have to have my AMP on, and music going (or system noises, depending on what I'm doing). Basically, my question is: I have the Opus 120 PSU. It doesn't shut down before the battery dies. It will run right up to the point where there's no juice, and then shut down the system. What do I have to do to get a Battery Gauge in my car to tell when the battery is at the "Stop playing w/your system" stage?

**2k1Toaster** · 09-06-2007, 02:16 AM

Originally Posted by briderx

I'm having issues..

I keep killing the battery on my car while sitting in my driveway trying to get my computer loaded and working right. I know that I can plug in an external PSU (which I have done). But in order for me to get everything working correctly, I have to have my AMP on, and music going (or system noises, depending on what I'm doing). Basically, my question is: I have the Opus 120 PSU. It doesn't shut down before the battery dies. It will run right up to the point where there's no juice, and then shut down the system. What do I have to do to get a Battery Gauge in my car to tell when the battery is at the "Stop playing w/your system" stage?

Well you could use the Fusion Brain as a permanent battery monitor, or you could just hook up a multimeter to your battery. When you see the needle dipping, its time to turn it off.

Also, you could just keep your car on. When I do maintenace I just start the car and let it idle. Burns almost no gas. I have let the car idle for about 70hours straight with a huge huge huge load being pulled off the alternator (waiting outside Walmart in a tent, it powered everything from space heaters to a plasma tv) and still had like a half a tank or more left. Idle eats no gas.

**Ruffy** · 09-06-2007, 09:08 AM

simple voltage meter w\anl fuse can be had for $10-$15

when working on the carputer I just plug it in to the wall, as for the screen/other stuff, I have a ac -> dc 14v power supply.

Idling that long is not good for a car.

**briderx** · 09-06-2007, 09:25 AM

How does windows monitor a laptop battery? Can't it do the same with a car? Or is there something in the battery that tells windows that it's low?

**nobb** · 09-06-2007, 10:18 PM

Why is idling too long not good for the car? Maybe try getting a high current battery charger, or a high current power supply that puts out 14.0-14.5 volts DC. You can just plug that in parallel with the car's electrical system, then youll be able to use all your car electronics without draining the battery. I am actually looking for something like this for my car, so if anyone knows of any cheap units, please post link.

**Alanh** · 09-06-2007, 11:40 PM

Here are a few things that come to mind.

The OPUS specs claim it will automatically shut down before the battery is discharged. According the specs on the web there are jumper settings for the voltage at which it shuts down. Have you checked the jumper selection to make sure its not too low? (Of course if you're running a bunch of other stuff off the battery, the OPUS shutting down may not save you there unless its all controlled some way.)

There are various other devices available that claim to disconnect loads from the battery if the voltage gets too low that might work for disconnecting everything.

There are fancy battery monitors used in the boating world that can monitor the charge remaining in a battery or bank of batteries. None of these are low cost that I'm aware of.

You may not need any of the things mentioned above if you provide external power which seems like what you really need in this case.

You may be able to just put a battery charger on with enough current capacity to run your electronics with the engine off. You can spend a little or a whole lot on a charger. I can't recommend any brand.

Another option is a stand-alone DC power supply that puts out 13.8V nominally. They are used by CB and Amateur radio operators to run radio transceivers off AC power. With one of these, you'd disconnect your battery and connect the power supply to your power bus and you can then test as long as you like without draining the battery. I'm not endorsing any of these as some have better reputations then others, but Workman, MFJ, Pyramid, Astron, Radio Shack are a few names I know of. If you want opinions, check out the power supply reviews at eham.net.

I'd still want to know if the OPUS is working correctly and if you've got the jumper selections you need because you don't want to get stranded somewhere because of a discharged battery in some other circumstance.

**briderx** · 09-10-2007, 03:47 AM

Originally Posted by Alanh

Here are a few things that come to mind.

The OPUS specs claim it will automatically shut down before the battery is discharged. According the specs on the web there are jumper settings for the voltage at which it shuts down. Have you checked the jumper selection to make sure its not too low? (Of course if you're running a bunch of other stuff off the battery, the OPUS shutting down may not save you there unless its all controlled some way.)

There are various other devices available that claim to disconnect loads from the battery if the voltage gets too low that might work for disconnecting everything.

There are fancy battery monitors used in the boating world that can monitor the charge remaining in a battery or bank of batteries. None of these are low cost that I'm aware of.

You may not need any of the things mentioned above if you provide external power which seems like what you really need in this case.

You may be able to just put a battery charger on with enough current capacity to run your electronics with the engine off. You can spend a little or a whole lot on a charger. I can't recommend any brand.

Another option is a stand-alone DC power supply that puts out 13.8V nominally. They are used by CB and Amateur radio operators to run radio transceivers off AC power. With one of these, you'd disconnect your battery and connect the power supply to your power bus and you can then test as long as you like without draining the battery. I'm not endorsing any of these as some have better reputations then others, but Workman, MFJ, Pyramid, Astron, Radio Shack are a few names I know of. If you want opinions, check out the power supply reviews at eham.net.

I'd still want to know if the OPUS is working correctly and if you've got the jumper selections you need because you don't want to get stranded somewhere because of a discharged battery in some other circumstance.

Alright, here's the deal.. I JUST read this as of 2 minutes ago. I knew there was a setting on the Opus somewhere that said it should check the battery level. I haven't checked since I thought of that, as I really haven't had time. BUT, I will check when I get home tomorrow from work and see if there's something to change. I was hoping maybe Windows would regulate the battery levels, like they do on laptops.. But I guess not?? ANyways, bedtime!