# Battery backup for irrigation system



## Mike Reilley (Jan 2, 2008)

At the SWGRS this weekend, I spoke with a friend of mine regarding how long she irrigates her GRR and what kind of watering system she uses. She watered daily, sometimes twice a day during the HOT summer months. During the conversation, she told me a story of a club member here in San Diego that left for two weeks in August, and when he returned, he came home to a completely dead GRR plant situation. While he had been gone, there had been a power loss and his controller hadn't restarted...so nothing was watered.

Now I have a new flash memory based irrigation controller that has a battery in it to keep its clock and processing going during power outages but I realized from this discussion that if the power outage was an extended one...as might happen if a bad fire took out power for days like the snow has in Connecticut...while the clock would keep going, there's be insufficient power to run the valves. 


Has anyone got a solution for this? How would one keep the irrigation system operating if power was out for days? I realize I could install a whole battery charger/battery/inverter hookup to keep it powered, but perhaps there's a simpler solution. Any ideas?


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## Brandon (Jul 6, 2011)

It's a long story but my watering system happens to be connected to a 1500va UPS along with another piece of hardware. I've had power go out several times for the night when the yard is to be watered and the UPS did make it through the entire time of watering my yard. However, I think this is overboard solution for your problem. My irrigation system is only 3 years old however it doesn't have a battery option thus it's connected to a UPS. There's "build in memory" but I have had it reset the time and date (but not the programming) three times during some power failures and I had the UPS nearby so I just plugged it into that and my problem was solved. New consumer irrigation systems run $30-$60 depending if it's 6 to 14 zones and as long as it supports a battery (9v) you should be fine with just one of these _ Unless_ the power is out for multiple days. Chances are if your power is out for multiple days you can hand water. If you're on vacation then having a neighbor call you if power is out for over a day would work as well. I know some hobby green house growers who have UPS's but after 20 years of experience with almost all brands most you can expect to last 2-4 years is all which is expensive to keep replacing batteries (or the entire unit). New consumer irrigation controllers also have some pretty nice features like multiple programs (ie: you can set drip or sprinklers for flowers to come on 2-3 times a day but your grass sprinklers only once).


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## toddalin (Jan 4, 2008)

There are certainly systems that are powered by battery for the timer, but use the city water pressure to run without the need for city power to activate the solonoids. But these are typically connected directly to your hose bib so you are limited to one "station." I guess you could make a "bib manifold" to run several sequentially.


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## Greg Elmassian (Jan 3, 2008)

The simplest is a cheap UPS, and one you could interrogate remotely through your network. 

All my stuff runs from a single server, which has a battery backup, lights, sprinklers, fountains, etc. This way, while there is a single point of failure, it's normally a failure with the UPS not wanting to turn back on. Since my UPS does a weekly and monthly test, then all that happens on a power outage that exceeds the battery backup time, is to restart the UPS (only sometimes). 

I'd just put a big ups on your system, and it should run your system for a long time on battery. 

Greg


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## VictorSpear (Oct 19, 2011)

As long as the Sun is still around, we should make use of it. One solution could be to embed a micro solar panel with the irrigation controller. 
Something like this perhaps ? http://www.brazix.com/prodfly.asp?ItemPN=BRXCTRSLR1&gclid=COmKjaeypawCFY5Y7AodCG19FA 

Cheers, 
Victor


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## Greg Elmassian (Jan 3, 2008)

Have you measured the current it draws? Should be trivial, most when a solenoid is open. 

Greg


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## VictorSpear (Oct 19, 2011)

Haven't had the opportunity yet, but your'e right..I'd use a better battery combo with one of those low cost 2 watt Sunforce chargers... 

I have a different problem - surrounded by too much water and too much Sun.


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## jake3404 (Dec 3, 2010)

Well, I was thinking in a little larger terms. We use a solor system to power a electric fence for cattle. The system is actually pretty compact. The array is about a 16" x 12" size mounted on top of a 4' pole. Then we use two car batteries connected in series to provide the power to the fence. It provides more than enough power to charge the fence overnight and then some. 

I would think this would be more then enough for your power needs.


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## Mike Reilley (Jan 2, 2008)

The valves pull 1/4 amp. So, at 28 volts, they burn up 7 watts/hour of operation. I have three valves...so that's 21 watts/hour of operation per cycle. They run daily for less than 30 minutes per cycle. That would work out to around 10.5 watt/hours/day max. Given that, a 1000va/700w UPS (a little one), should be able to support operations on my GRR for 66 days.


I'm off to buy a little UPS.


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## Tomball Bob (Oct 10, 2016)

Thanks folks, this was funny. I was searching for a way protect my house sprinkler system from those 1 second power outs that force me to go into the garage and reset the date/time so the sprinklers come on when they should. I mostly ignored the "Large Scale.." id on the website and just read the various posts, not realizing you might be talking about a (what is a this?) GRR.

I love trains, always wanted to make some space for HO or maybe N scale and here I stumble on something that might get me motivated again (lots of work right, need lots of time, I haven't had much). Oh well good ideas you have. We are buying a stationary whole house generator and of course the problem with that is they don't kick in quickly enough (nor should they) to cover the monthly 1 sec power clips. So I'm looking at one that runs on battery and hopefully also on A/C.


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## John J (Dec 29, 2007)

Why not use a battery back up system like one would use for a computer? We use to use one to run cooling fans on a Inferred Dryer if there was a power failure. When the power failed the battery back up ( USB) from a computer would run the fans to cool the lamp cases. 

JJ.


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## primpwrsolution (Apr 24, 2020)

Hello there, when we utilize our U8903a with ethernet remote, at that point a similar estimation, we can do likewise from the front board gives us an altogether different outcome. Generally substantially more clamor and THD is estimated utilizing ethernet, than measure it from the front board. Is there any known issue with an answer for this, we could utilize? much appreciated, tamas


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## toddalin (Jan 4, 2008)

I installed a "whole house" generator panel (10 breaker 15,000 watts) and the garage, housing the sprinkler controller, is one of the switchable circuits. So, if I switch on the generator, such as during a brown out in the heat of summer, the sprinkler system works.

(Don't neglect the garage. Though possible, it makes it hard to get the car out if the opener has no power.)

Obviously, if I'm not home, there is no one to connect and turn on the generator, but we're always home.

Panel connection to main breaker panel:









60 foot 6 gauge x4 conductor cable to generator:









Generator stored in garage by back door:









Generator in position. Part of the engine and the exhaust sit outside:


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## Greg Elmassian (Jan 3, 2008)

primpwrsolution said:


> Hello there, when we utilize our U8903a with ethernet remote, at that point a similar estimation, we can do likewise from the front board gives us an altogether different outcome. Generally substantially more clamor and THD is estimated utilizing ethernet, than measure it from the front board. Is there any known issue with an answer for this, we could utilize? much appreciated, tamas



So a U8903a is an audio analyzer, which indeed can measure THD (Total Harmonic Distortion)


But using the audio analyzer remotely with a battery backup or UPS would probably work.


If this is what you are asking, you do need to look at the power consumption, and determine the size of UPS required.


Greg


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