Question about battery back-ups

Scrambled

Active Member
I am wanting to get a battery back-up, but I don't know what size to buy. How many watts is enough and how many would be to much (if you can have to much). I also think I want the smart system.

What is everyone else using?


Steve
 
You need enough watts to supply the equipment you want to keep running. It is usually referred to VA (volt-amps), which is equal to watts in a simple case. Computer power supplies are not "simple", so VA is more accurate. If you get a UPS that can supply more VA than you need, that usually means you get more run-time. You will have to decide how much run-time you want. If you plan on just doing safe computer shut downs as soon as the power fails, all you need is 5 minutes or so. But if you want to try and keep things running until power returns (in a reasonable time), then you need bigger batteries. APC is a very popular brand, with MANY models & sizes.
 
I think APC has a calculator on their site. Depending on the load, Costco has a tripp-lite version of a 1000va version for $99 (the APC version will go for $150+ if I remember).

I was considering that one myself.

If you want to really expand this project, look into standby generators. These kick on within a fraction of a second (if I remember correctly) and take up the slack for the power company if power fails.

Very cool and avoids switching circuits or starting a generator (they automatically test themselves). I am not positive that the response is quick enough to negate the need for a ups though as it has been awhile (but then again I have multiplied the cost by a few thousand). When I finish all my other projects in the house (do the math...) this might be a nice one to have...
 
If you are using the X10 protocol. Many UPS units are not a pure AC out. I peronally fried a TM751 with this waveform. Also the noise from the inverter in theese units messed up the X10 signals and a their surge and spike filters absorbe the X10 signals. My APC BX1000 needs an X10 Filter on it's AC Line Cord or it kills all the powerline X10 Signals. Not enough data on it and Insteon Signals.
 
Related to UPS discussions, Cinemar is about to beta test a new MLWMI plugin that allows for centralized management of all PCs on the LAN on things like UPS and battery condition. The Server tracks all client PCs status and allows for automated tasks to be performed if something is suspect or requested. Print screens to follow...
 
Mike said:
If you want to really expand this project, look into standby generators. These kick on within a fraction of a second (if I remember correctly) and take up the slack for the power company if power fails.
If you are talking about cutting over in a fraction of a second I think you are talking about a whole-house inverter rather than a generator. These are just giant UPS systems with racks of batteries and a separate inverter.
 
Sorry I meant something like this:

http://www.homegeneratorsystems.com/difference/index.cfm

I also think I confused the transfer time with the unit that you mentioned from things at work. The home versions do not have batteries and kick in after 3 seconds of no power.

A nice concept, but it also depends on where you are. If you have a lot of power outages it can be real nice. All that being said, I've been here for a few years now and would not have had the opportunity to use something like this yet. I'm betting it would be a nice addition for some down south.
 
Mike,

We are due for a nasty hurricane by us pretty soon. I put in a generator transfer switch and picked up a small 5.5Kw generator for "just in case" a few years ago. The way I set it up I can be up and running an about 10 mins. I just have to wheel the generator outside, hook up the cable, gnd the generator (a must) and start it up. All for under $800 (then).

LIPA (the local power company for those not from LI) says that Long Islanders could go for weeks without power if we get hit with a decent hurricane (Cat 3 or more). You might want to bump a generator up on your "to do list" cause you never know.

You just need to run it a few hours a day to keep the refrig etc going, cook a few things in a micorwave, do laundry, charge some batteries etc. Myabe run an airconditioner for a little while to cool off the house if need be.
 
From somebody who has been through several hurricanes, most recently Wilma I can tell you a generator is like gold. People were killed for less. Trust me, you will run the gen more than you think. I have a 5500W continuous, 8000W peak gen. It is important to account for peak usage like a refrigerator or air conditioner starting up. They take much more to start than to run.

If I was starting from scratch or do it over again (and I still might anyway) the permananet generators like in the link above or the popular Guardian are the way to go. One of the problems with a generator after a major storm is getting fuel. If you have a portable and anticipate (like an approaching storm) make sure to stock up on fuel. Same thing for the permanents, fill the tank!
 
Mine is 8Kw peak as well which is all I could afford at the time. Some day I will put a larger one in. And I usually keep 15 gals on hand for the huricane season and I also fill the cars etc. You only need a few gals a day to get by with minimal usage. And if the neighbors bring over food etc for the freezer you can always hit them up for gas ;)

Always use fuel stabilizer at the begining of the season. I also fire up my generator every month or so (with a load on it).
 
During a house remodeling in my neighborhood, I noticed that they installed a large propane based generator. They also installed a large propane tank (and I mean really big, about 3-4 ft diameter) in a closet in the garage.

I guess that they have enough fuel for a few weeks, and in case of needing more this is a fuel that does not become scarse during hurricanes (vs. gasoline or diesel). Moreover, propane in a tank is more stable than diesel and more secure that gasoline.
 
While a propane generator is much more practical in some respects it is also much more expensive than a portable generator.

I will update mine someday.... then again maybe I will put in solar panels and an inverter with battery backup and keep the portable generator.

The cost of a permanently installed large capacity generator is about 1/3 of what I would need to go solar (after all of the rebates) and the solar would eventually pay for itself. And in case the panels blow away in a huricane I would still have the generator to recharge the batteries (generators are so noisey to run at night etc.).
 
Digger said:
LIPA (the local power company for those not from LI) says that Long Islanders could go for weeks without power if we get hit with a decent hurricane (Cat 3 or more). You might want to bump a generator up on your "to do list" cause you never know.
Hmm good point. I have been hearing about that, and I do know it was bad with some of the big storms like the ice storm in the 70's (think that is when it was) and gloria in 85-86.

I will have to give that some more thought.
 
I put mine in myself and had a licensed electrician check out my work afterwards. I would not reccomend someone doing this on their own as far as installing a transfer switch. If you go with a portable generator make sure you have the means to ground it. I have a ground rod installed right outside the garage behind my electrical panel where I can ground my generator. Technically it grounds through the interconnecting cable (its 4 conductor with two phases, neutral, and ground) but you should ground it anyway just in case.

I have a limited budget so I do much of my work myself. I am fortunate to have friends and family that are electricians, alarm installers etc. Since I am a non degree'd Electrical Engineer (basically my employer recognizes me as an Electrical Engineer even though I dont have a degree) I also have enough knowledge and experience to keep myself out of trouble.
 
elcano said:
They also installed a large propane tank (and I mean really big, about 3-4 ft diameter) in a closet in the garage.
I didn't think that the US allowed indoor storage of propane. Is PR different? Or was this not really an interior closet? Or am I wrong about the US rules too? My 100 gallon propane tank is buried.
 
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