UPS Battery backup for chasing?

[Verne Carlson]

I just bought 500va UPS battery backup for my home system. I was thinking how great it would be to have this thing connected to my inverter in my car and then have my wx-worx, ATI TV system and my laptop on it. My laptop is of course all ready battery backed up internally but the other systems aren't. It would be nice to turn off my car engine, have everything still running (for up to 20 minutes?) and not have it drain my car battery. Has anyone else had any luck chasing with a UPS?

 

[mrobinett]

Tried it. apparently the unit I got monitors the ground fault (the third prong) and a warning beep sounds constantly and eventually shuts off because it detects no continuity on that circuit and its telling you your wiring in your house is bad, duh, its in the car! Thats about as far as I got, it now backs up my entertainment center in the house, keeps the time on the VCR and receiver from needing to be reset.

It may be able to be modified or the unit you have may work ok. I tried the APC ES-350.

Hope this helps.

 

[John Erwin]

I had thought about something like that, but decided that it would be unsuitable for my needs.

I ended up purchasing a deep-cycle sealed battery and have it hooked up to the car via an isolater. I run the laptop and some of the other stuff from this source. Some items are powered directly from the battery, others are powered through an inverter. I can keep my laptop powered for several hours off this battery without the car running. Originally I had envisioned adding a solar panel to help keep this battery charged, however it hasn't been necessary yet. The whole setup is designed to be removeable when I don't need it.

 

[Edward Ballou]

Are there any sites that document how to get a second battery and run various things off of it. This would include what you should buy, how you should install it, what kind of inverters you need, etc?

 

[John Diel]

You might take a look at David Drummonds set up. He's got a battery on an isolator though he may be using it as a strict back up. I know most isolator switches have a Bat 1, Bat 2, or Both positions. I seem to remember that in our amulances, some things were powered by Bat 1, others by Bat 2, so when you were coming back in with a transport, you ran both Bat's. On the way out, you ran with Bat 1. However, it's been a long time and my memory falters a bit from those days.

 

[John Erwin]

*apologies for thread-jacking*

The key component in the second battery setup is the isolater. Basically it's function is to permit the 2nd battery to receive charging current from the alternater without "robbing" the primary vehicle battery of current when it needs it. Thsese are commonly used in RV's by the way. When selecting an isolater, it's important to get one suitable for the task ie: matched to the alternator output of your vehicle. I selected one from http://www.hellroaring.com/; these units are mosfet-based instead of the usual diode units (which are adequate in any case). Some isolaters will also allow your second battery to boost the primary car battery with a flip of a switch.

I elected to use a deep-cycle battery for my second battery because I wanted to be able to run my setup on battery power alone if necessary. Running a regular car battery below a certain voltage will permanently damage it; deep-cycle batteries are designed to handle this without damage (commonly used in marine and RV applications). At this point I should mention that if you intend on putting the second battery inside the passenger compartment of your vehicle you should ensure that you use a "Sealed" type battery; regular battery packages emit highly explosive hydrogen gas that needs to be vented. Sealed batteries are a bit expensive, but also ensure that no spills occur if the battery is tipped over. Of course if you have enough room to put the battery in your engine compartment then you won't have an issue with this (see David Drummonds article for extended info on this).

As for connections, I have a distribution block that I can attach some 12 volt devices directly. I also have an inverter connected to the battery for anything that needs it. Inverter selection should be based on how much power you need; you should also note that the wattage quoted on the inverter is usually the "peak" wattage that the unit can handle, not the normal operating wattage. A laptop generally only needs around 50 watts to run (approx), so a 75 watt unit might suffice (although I would recommend a 150 watt unit). 300 or 400 watt units can be had for excellent prices these days. The higher wattage units require direct connection to the battery to get the full output out of them; the cigarette-lighter connection on a vehicle should not be used for high-current applications.

 

[Edward Ballou]

Thanks John, great info. So I got the deep-cycle sealed battery down and what kind of inverter I need. (Main use of the inverter is a laptop and cell phone charging)

Another thing in the whole process I'm concerned about is the 3-prong powerstrip that I'd like to plug all my gizzmos into. How do you run this to the battery or inverter?

 

[John Erwin]

Originally posted by Edward Ballou
Another thing in the whole process I'm concerned about is the 3-prong powerstrip that I'd like to plug all my gizzmos into. How do you run this to the battery or inverter?

I assume you're talking about a 115v power bar? That would need to go to the inverter. Some of the 400watt+ units have 2 or more plugs on them though.. you may not need the powerbar.

 

[Edward Ballou]

How many Ah should we need? I see that the difference in prices for the deep cycle sealed batteries is based upon this.

 

[John Erwin]

Originally posted by Edward Ballou
How many Ah should we need? I see that the difference in prices for the deep cycle sealed batteries is based upon this.

I have a 50Ah battery that works quite well. This will not be too critical for this application, so get what your budget will allow for.

 

[Tom Burgess]

The best way to do this is to go to your local car radio shop or rv parts place and get the iso. it does not need to be anything fancy. also pick up a fuse block that holds 2 or three large fuses. Also a single line fuse. A car battery placed under the hood and a line run from the current battery to the iso and then to the new battery. A small hot line to a acc. spot that only comes on when the car is running only. This allows you to charge the battery while driveing,but park and not worry about not being able to start. Get the biggest inverter you can. Why? never fails you sooner or later will want to add something. That is also the reason for the fuse block. All inverter shutdown at 10v to keep from damageing the inverter so deep cycle batteries are not needed. And just to answer how I know this. I hve been fitting emergency units for 30 years includeing our current chase unit which can be seen at www.wxtech.com

 

[John Erwin]

Originally posted by Tom Burgess
A small hot line to a acc. spot that only comes on when the car is running only. This allows you to charge the battery while driveing,but park and not worry about not being able to start.....All inverter shutdown at 10v to keep from damageing the inverter so deep cycle batteries are not needed.

Sorry Tom, but I'm going to have to argue with you there on several points.

First of all, the isolator hookup will vary with the unit being used; always follow the directions for the particular device.

Secondly, while cheap diode isolators will do a reasonable job, they do have an annoying tendancy to not charge the second battery to full capacity due to the voltage drop across the diodes. Maybe not a huge deal for some, but not great if you want top efficiency out of your second battery.

Third - I would not want to rely on the inverters capability to "save" your cheapo car battery. Draining an average car battery to 10volts will cause unreversable damage to it. While you can sucessfully use a car battery for a second battery in these setups, careful management of the voltage is necessary. Since I prefer to operate my setup sometimes on battery power alone, I wanted a "deep-cycle" battery than can stand a good drain cycle.

Fourth, I was under the impression that Ed was going to be putting battery INSIDE his vehicle.. meaning that a sealed battery would be almost mandatory for safety sake (although with a lot of work you could arrange to vent a common type battery.. but why go through the hassle?)

Regards,

 

[Tom Burgess]

Originally posted by John B Erwin+--><div class='quotetop'>QUOTE(John B Erwin)</div>

<!--QuoteBegin-Tom Burgess

A small hot line to a acc. spot that only comes on when the car is running only. This allows you to charge the battery while driveing,but park and not worry about not being able to start.....All inverter shutdown at 10v to keep from damageing the inverter so deep cycle batteries are not needed.

Sorry Tom, but I'm going to have to argue with you there on several points.

First of all, the isolator hookup will vary with the unit being used; always follow the directions for the particular device.

Secondly, while cheap diode isolators will do a reasonable job, they do have an annoying tendancy to not charge the second battery to full capacity due to the voltage drop across the diodes. Maybe not a huge deal for some, but not great if you want top efficiency out of your second battery.

Third - I would not want to rely on the inverters capability to "save" your cheapo car battery. Draining an average car battery to 10volts will cause unreversable damage to it. While you can sucessfully use a car battery for a second battery in these setups, careful management of the voltage is necessary. Since I prefer to operate my setup sometimes on battery power alone, I wanted a "deep-cycle" battery than can stand a good drain cycle.

Fourth, I was under the impression that Ed was going to be putting battery INSIDE his vehicle.. meaning that a sealed battery would be almost mandatory for safety sake (although with a lot of work you could arrange to vent a common type battery.. but why go through the hassle?)

Regards,[/b]

I never use diode isolators, We only use selinod isolators which is a special style switch just for this type of job. This allows both batt. to charge fully. Batteries have come a long way in the past few years. the old sayings no longer hold tru like dropping battery voltage will kill a battery and who can forget when setting a battery on concrete would mean a new battery.

While I never like a battery inside and never encouarge anyone to do so. Most of the time a place can be made under the hood . If it must be put inside a sealed battery will be a must.

 

[John Erwin]

Mmm okay.

I'm going to make this my last post on this before it turns into a problem thread... however some things need to be said.

Anybody contemplating hooking up a second battery to thier vehicle needs to research it properly prior to implementation. I would recommend visiting the http://www.hellroaring.com/index.htm site for some excellent information on how to do this (there's several diagrams for different situations). Theres a few other good sites as well.

Some of the previous advice being given in here may result in undesirable side effects, if not outright damage.

 

[Tom Burgess]

As always you have to do what you think is best. And advise is like as%% everyone has it to give. I agree you need to research it before starting.