understanding battery backups

[sao123]

ok...i admit it. I phail at understanding electricity.

Hopefully this question is simple enough... given the recent state of storms in the north east, ive decided to "emergency prepare" my house somewhat more... what I need though is some "knowledge"... not necessarily the "answers"...

Currently, i have a tankless hot water heater, which draws some current for an ignition spark, and then continuous 3 watts for an exhast fan. While not in operation, it draws nil, or practically nil power.

I was considering buying an UPS that would alloww me to have hot water during a power outage... how can i calculate what specs of a backup to buy? VA, Watts, Time...etc.

If my belkin F6C-1200 is rated at 670Watts 1080Joules and 100 Minutes... I want to see how long this will allow me to have hot water for, and if I dont run the water at all, how long will the battery stay fresh enough to use.

670W for 100Min = 3 Watts for XX Minutes?

If I were to buy a ups... do I need more watts, joules, or VA?

 

[Modelworks]

ignition transformer - probably 1A or less = 120 watts
Fans - 120vac @ 3 watts = .025 amps + 10% (motors have a current spike when first turned on)

Most probably not more than 125 watts total. If the UPS is rated for 670W for 100min then it could power the heater for a total of 5 hours minimum, 1hour @ 5 different times or however you want to break it up.

 

[William Gaatjes]

ok...i admit it. I phail at understanding electricity.

Hopefully this question is simple enough... given the recent state of storms in the north east, ive decided to "emergency prepare" my house somewhat more... what I need though is some "knowledge"... not necessarily the "answers"...

Currently, i have a tankless hot water heater, which draws some current for an ignition spark, and then continuous 3 watts for an exhast fan. While not in operation, it draws nil, or practically nil power.

I was considering buying an UPS that would alloww me to have hot water during a power outage... how can i calculate what specs of a backup to buy? VA, Watts, Time...etc.

If my belkin F6C-1200 is rated at 670Watts 1080Joules and 100 Minutes... I want to see how long this will allow me to have hot water for, and if I dont run the water at all, how long will the battery stay fresh enough to use.

670W for 100Min = 3 Watts for XX Minutes?

If I were to buy a ups... do I need more watts, joules, or VA?

Let me see if i understand correctly...
You mention the ignition spark, that mean i can assume that your heater uses the burning of some form of natural gas to heat the water.

The ignition will only be used to start a flame. Then it will be switched off.
That will ony be for maybe 3 seconds.

The 3watts will be the primary use of power with a short 3 second 125W power spike from the ignition.
I may be overlooking something though...


But if you suspect that you could experience a power fail from the power company, would it not be better to buy a small generator ?
I can imagine that in freezing weather you do not need the refrigerator. With a power fail i assume no internet D: .Radio can be battery operated(That is, if the storm allows reception even in the lower part of the rf spectrum)... And old fashion books and board games keep the boredom away... Tv is most of the time just commercial, so no miss there...

 

[DominionSeraph]

The F6C-1200 will do half-load for 4 minutes. That would correlate to 400 minutes at 3 watts, except efficiency plummets at low loads.

The joule rating is for surge suppression. http://www.kerchner.com/electrical/watt.htm

For time, you want amp-hours of the battery. Good luck finding that.

How long it will store with no draw? No idea. But if it isn't smart enough to shut down when there's no load, I wouldn't bet on more than a day.

 

[sao123]

Let me see if i understand correctly...
You mention the ignition spark, that mean i can assume that your heater uses the burning of some form of natural gas to heat the water.

The ignition will only be used to start a flame. Then it will be switched off.
That will ony be for maybe 3 seconds.

The 3watts will be the primary use of power with a short 3 second 125W power spike from the ignition.
I may be overlooking something though...


But if you suspect that you could experience a power fail from the power company, would it not be better to buy a small generator ?
I can imagine that in freezing weather you do not need the refrigerator. With a power fail i assume no internet D: .Radio can be battery operated(That is, if the storm allows reception even in the lower part of the rf spectrum)... And old fashion books and board games keep the boredom away... Tv is most of the time just commercial, so no miss there...

as much as Id love to have a generator, theres a big difference between a $100 UPS and a $1500 generator, plus I think the boro has anti noise ordinances.

I can already heat the house with Kero... so all we need is hot water.

 

[sao123]

ignition transformer - probably 1A or less = 120 watts
Fans - 120vac @ 3 watts = .025 amps + 10% (motors have a current spike when first turned on)

Most probably not more than 125 watts total. If the UPS is rated for 670W for 100min then it could power the heater for a total of 5 hours minimum, 1hour @ 5 different times or however you want to break it up.

So I could maybe get about 8-10 (20 minute) showers or about 5 days if I shut it off between.

 

[westom]

as much as Id love to have a generator, theres a big difference between a $100 UPS and a $1500 generator, plus I think the boro has anti noise ordinances.

A $100 UPS outputs electricity so 'dirty' as to may be harmful to small motors and power strip protectors. This power is perfectly ideal to computers and other electronics. Not apparent (insufficient electrical information) if that 'dirty' UPS power is harmful to water heater functions.

To 'without a doubt' get a UPS that should not be harmful would mean a $500 UPS.

If generator noise is a problem, you are wasting money on crappy and overpriced generator. So many reasons why informed consumers buy Honda generators. Noise, their ability to properly respond to changing loads, low gasoline consumption, and other electrical output parameter are but a few.

 

[ussfletcher]

You could always just run an inverter off of some car batteries too


Jeeze, sometimes people make it too difficult.

 

[William Gaatjes]

i was thinking, Assuming you have a water heater powered by natural gas
usually the high voltage ignition circuit only consumes a few watts or so. It really is a real small transformer. Even the old high voltage crt power supply of 25 KiloVolts was barely 20 watts. Most power went into the coils with good ol crt television sets. To create a spark for a heater a transformer of 1 to 3 watts is more then sufficient.

I do not know what type of heater you have, but if it has some electromagnetic valves, these will consume some power, the fan for the exhaust will consume some power but that's it. The electronics does not consume that much electricity. In the end, A car battery with an ups would be an idea. There is only one issue, most ups are not designed to work continuously. That is, when you connect them, they just pass the mains power to your pc with a relay. When there is a power fail, the electronic circuit takes over. This system is capable of delivering power long enough for your server/pc to shut down and not loose valuable data.

There are also ups systems that directly feed of the main supply and create a mains supply of their own feeding your pc, but these are a lot more expensive.

A cheap way would indeed be a car battery hooked up to a ups, but do not run the ups continuously.
The best way would indeed be a car battery hooked up to an inverter.

 

[sao123]

i was thinking, Assuming you have a water heater powered by natural gas
usually the high voltage ignition circuit only consumes a few watts or so. It really is a real small transformer. Even the old high voltage crt power supply of 25 KiloVolts was barely 20 watts. Most power went into the coils with good ol crt television sets. To create a spark for a heater a transformer of 1 to 3 watts is more then sufficient.

I do not know what type of heater you have, but if it has some electromagnetic valves, these will consume some power, the fan for the exhaust will consume some power but that's it. The electronics does not consume that much electricity. In the end, A car battery with an ups would be an idea. There is only one issue, most ups are not designed to work continuously. That is, when you connect them, they just pass the mains power to your pc with a relay. When there is a power fail, the electronic circuit takes over. This system is capable of delivering power long enough for your server/pc to shut down and not loose valuable data.

There are also ups systems that directly feed of the main supply and create a mains supply of their own feeding your pc, but these are a lot more expensive.

A cheap way would indeed be a car battery hooked up to a ups, but do not run the ups continuously.
The best way would indeed be a car battery hooked up to an inverter.

would i thin recharge it with a standard recharger? some type of electric motor belted to an alternator?

 

[bobsmith1492]

would i thin recharge it with a standard recharger? some type of electric motor belted to an alternator?

Just use a cheapo battery charger and leave it on all the time. Make sure to use a deep-cycle battery, like a boat battery, and give it some room for ventilation. We were using a standard tractor battery in this type of situation at work, and after a couple of months it literally exploded - it wasn't too bad but it did spray sulfuric acid on a couple of people and scared the pants off the ladies downstairs. That's why you get a battery that is vented, not sealed.

 

[sao123]

ok so again, help me with the calculations:

If I get a battery from my local walmart rated:

Power Ratings:
Cold Cranking Amps (CCA at 0 deg.F): 675
Reserve Capacity (RC): 200 min.
Amp Hours at 20 Hour Rate: 115

and
http://detonator.dynamitedata.com/c...CODE=GOOGLEBASE&cm_mmc_o=VRqCjC7BBTkwCjCECjCE
http://www.tigerdirect.com/applicat...CODE=GOOGLEBASE&cm_mmc_o=VRqCjC7BBTkwCjCECjCE

this 1000W inverter from tiger direct... I should have power for how long under the above load?

 

[sao123]

dayum... if I did the calculation right, i could run 42 watts continuously for about 47 hours... that would power 3 13watt CF lamps, and the 3amp water heater...

WIN.

 

[bobsmith1492]

The main problem with that inverter is the line:
"No-load current draw: < 0.3 Aac"

I'm not sure what they mean by Aac, but if they really mean Amps AC, that's 36W of current draw just by sitting there. So, with your 115 amp-hour battery at 12V, that's about 1380 watt-hours. 1380WH / 36W = 38 hours.

If you add in, let's say 5W for your fan and heater ignition, that's about 41W, so 1380WH / 41W = 33 hours.

You're probably better off with a smaller inverter, like 100W or so. It wouldn't draw as much current while it is "idling" with no load.

Also try to get a boat battery with a maintenance charger; car batteries are not made to be completely discharged multiple times and it will reduce their total capacity and lifespan.

 

[sao123]

The main problem with that inverter is the line:
"No-load current draw: < 0.3 Aac"

I'm not sure what they mean by Aac, but if they really mean Amps AC, that's 36W of current draw just by sitting there. So, with your 115 amp-hour battery at 12V, that's about 1380 watt-hours. 1380WH / 36W = 38 hours.

If you add in, let's say 5W for your fan and heater ignition, that's about 41W, so 1380WH / 41W = 33 hours.

You're probably better off with a smaller inverter, like 100W or so. It wouldn't draw as much current while it is "idling" with no load.

Also try to get a boat battery with a maintenance charger; car batteries are not made to be completely discharged multiple times and it will reduce their total capacity and lifespan.

wouldnt that be 3.6 watts? its only a 12 volt battery...


actually the above was a deep cycle marine battery. im assuming it has CCA for the boat motor. yes ill have to look for a deep cycle charger.

 

[sao123]

AAC vs ADC is confusing... found another 1000W inverter rated at .95ADC idle load.
how can i compare the 2?

 

[westom]

actually the above was a deep cycle marine battery. im assuming it has CCA for the boat motor. yes ill have to look for a deep cycle charger.

Doing that kludge assembly is dangerous. You never use those type batteries in a closed room.
The hardware for a typical UPS is so cheap that a replacement battery costs almost as much as the entire UPS. If spending that much for a vented battery without the many safety features, a plug-in UPS does same for the same price WITH existing safety features. The inverter is already inside a UPS. Also is another device - the battery charger designe so that no battery explodes. No battery must ever explode.

And a UPS also does the switchover automatically without human intervention.

Even with the $100 inverter, you still have 'dirty' electricity that may be harmful to existing electrical parts. Probably would not. But the $100 inverter potentially would be as harmful as the UPS.

Try it. No parts should be any warmer if powered off 'dirty' UPS (which is an inverter) power.

 

[sao123]

Doing that kludge assembly is dangerous. You never use those type batteries in a closed room.
The hardware for a typical UPS is so cheap that a replacement battery costs almost as much as the entire UPS. If spending that much for a vented battery without the many safety features, a plug-in UPS does same for the same price WITH existing safety features. The inverter is already inside a UPS. Also is another device - the battery charger designe so that no battery explodes. No battery must ever explode.

And a UPS also does the switchover automatically without human intervention.

Even with the $100 inverter, you still have 'dirty' electricity that may be harmful to existing electrical parts. Probably would not. But the $100 inverter potentially would be as harmful as the UPS.

Try it. No parts should be any warmer if powered off 'dirty' UPS (which is an inverter) power.

What?
#1 - we have already discussed that a standard PC ups will ruin the electric motor in the device.
#2 - a UPS gives emergency time in "minutes"... a deep cycle + inverter gives time in "days". I live in PA, we just had an 8 day power outage, and I refuse to take cold showers.
#3 - my basement / furnace room / natural gas hot water heater is hardly an enclosed airtight space. AGM batteries are safe for use indoors.
#4 - I dont need surge protection or a bunch of extra safety features... I need a cheap reliable emergency power source.

 

[sao123]

Try it. No parts should be any warmer if powered off 'dirty' UPS (which is an inverter) power.

lulz... its a tankless natural gas water heater... go ahead try to touch the motor of the exhaust fan while its running...

 

[westom]

What?
#1 - we have already discussed that a standard PC ups will ruin the electric motor in the device.
#2 - a UPS gives emergency time in "minutes"... a deep cycle + inverter gives time in "days". I live in PA, we just had an 8 day power outage, and I refuse to take cold showers.
#3 - my basement / furnace room / natural gas hot water heater is hardly an enclosed airtight space. AGM batteries are safe for use indoors.
#4 - I dont need surge protection or a bunch of extra safety features... I need a cheap reliable emergency power source.

That $100 inverter is the same output also found in PC UPSes.

A UPS provides has the power output of its battery just like any other battery. The cost of a UPS is virutally the cost of a battery.

No plug-in UPS is a surge protector. Once you eliminate popular myths, it is a battery charger, an inverter, and a relay to switch from AC mains to battery. You need safety features so that the battery does not explode. Again, how much is the UPS with safety features? About the same price as a battery - because those UPS circuits (like that $100 inverter) are actually so cheap.

 

[William Gaatjes]

I do not know the dimensions of your house, but if you 8 day power outages and you have a basement, the best way is a generator. Assuming you are not alone when the mains power fails, have a talk with 1 or 2 neighbours and buy 1 generator for all of you. I assume you are not using any air conditioning now and then a small generator would be powerfull enough to feed a few houses. But if you want a generator for each house, (which increases redundancy and gives you the option of helping each other out if a generator fails) Build a sound proof casing in your basement. Make sure the exhaust of the generator goes outside with some filters and you are ready to go. This is not easy but it is reliable. I assume your neigbours live close by because otherwise the generator should not be an issue.

Think about, share the costs...

http://www.hondapowerequipment.com/products/Generators/

The brochure
http://www.hondapowerequipment.com/pdf/Brochures/generator_brochure.pdf

In all honesty, this is not really eco friendly but hey... You can only do that on a large scale.


There is one more thing , let a qualified person who knows what he/she is doing do the wiring and proper installment of fuses /protection circuits or you have a problem.


It is either that or start learning about it and ease your life ^_^ ()

 

[sao123]

That $100 inverter is the same output also found in PC UPSes.

A UPS provides has the power output of its battery just like any other battery. The cost of a UPS is virutally the cost of a battery.

No plug-in UPS is a surge protector. Once you eliminate popular myths, it is a battery charger, an inverter, and a relay to switch from AC mains to battery. You need safety features so that the battery does not explode. Again, how much is the UPS with safety features? About the same price as a battery - because those UPS circuits (like that $100 inverter) are actually so cheap.

batteries dont explode unless you overcharge them... and since i wont leave it on 24/7 (it might only need charged 8-10 hours per month due to self discharge.) and it will be in a well ventilated area... it shouldnt be a problem.

 

[westom]

batteries dont explode unless you overcharge them... and since i wont leave it on 24/7

Reference to exploding batteries was to another poster who discusses exploding batteries as if that was acceptable. Those batteries exploded due to equipment without the necessary protection circuits.

Where in PA was someone without power for eight days?

How quiet are Honda generators? Due to a power failure, the cable company trucks arrived at a box mounted up on the pole. I never noticed until the trucks arrived. They had a Honda gnerator strapped to the box for temporary power. If their trucks did not stop there, I would have never known or heard that Honda generator. That is how 'noisey' every generator must be - to not be woefully obsolete technology.

 

[William Gaatjes]

I linked the brochure for specifications. But in al honesty when you read the typical marketing text... D:D:

 

[sao123]

Reference to exploding batteries was to another poster who discusses exploding batteries as if that was acceptable. Those batteries exploded due to equipment without the necessary protection circuits.

Where in PA was someone without power for eight days?

How quiet are Honda generators? Due to a power failure, the cable company trucks arrived at a box mounted up on the pole. I never noticed until the trucks arrived. They had a Honda gnerator strapped to the box for temporary power. If their trucks did not stop there, I would have never known or heard that Honda generator. That is how 'noisey' every generator must be - to not be woefully obsolete technology.

pretty much all of the southwest 5 county region... right after we got 24 inches of wet heavy snow