Ups/battery Back Up?

[jmchzn]

What do you use in case of a power outage? Generator not an option. Hampsters on a wheel not an option.

 

[BeanAnimal]

First you need to tell us what equipment you want to run during the outage. How long do you want that equipment to run? What is the wattage rating of the equipment. What is your budget? Why is a generator not an option?

 

[jmchzn]

back up

back up

ok I realized it after I posted. I'll get exact power ratings. all I think I ned to run is 1mag 18 and 1 mag 24. as far as I know I just want to keep skimmer and return going. I have never lost power for more than 5 hours in seven years. Tis the season and only second year with reef. FW only needed battery air stone for that amount of time. reef different story.

 

[BeanAnimal]

Well those are fair size pumps. You will need to have something that puts out a TRUE sine wave. That means CHEAP UPS systems are ruled out.


I would look at one of the Tripp Lite units that outputs a sine wave and is designed to be powered from several deep cycle batteries.

Lets just take a wild stand and say your two pumps draw around 300 watts total.

Lets also assume you get yourself 2 Deep Cycle batteries that are about 200 Amp Hours each.

That gives you 400 Amp Hours if you run them in parallel with the inverter. Your runtime would be somewhere in the neighborhood of 6 hours of runtime with NEW batteries.

What you MUST be aware of is that fact that batteries start to lose capacity from the day they are constructed. Batteries that are in a charge cycle will last about 18 months and still maintain about 70% of their capacity. From 18-36 months the degredation of the batteries is pretty steep. By 36 months they are pretty much worthless (maybe 20-30% of their capacity if you are lucky).

The next thing you MUST remember is that a power outage will draw down your cells. If you drop them below 30% or so of their charge, permanent capacity lost is certain. This means a few full discharges will shorten the life and you will no longer have that 18-20 month window for 70% capacity.

What does this mean? If you are shooting for 5 hours runtime. Then you need to build an array large enough that 5 hours will only use about 70% of the available storage capacity.

But wait... we are not done. You also need to consider that the power outage is not always going to occur when you have brand new batteries. So figure on them being about 70% of their rated capacity at any given time (and that is stretching it).

Put it all together and you will need an honest 800 Amp hours worth of cells to be comfortable in a 5 hour run time. That is (4) 200 Amp Hour batteries that must be replaced every 1.5 - 2 years.

It gets VERY expensive to maintain such a system... and a generator starts to look VERY affordable.

UPS systems are rarely used to support equipment for more than 30 seconds. This is the budgeted time for the genset to kick in and take over.

I hope this helps. I am not trying to discourage you. I am trying to help you get the big picture. People spend millions of dollars on UPS system and don't maintain them. 90% of the consumer units sold are at only 10% of so of their capacity.

Bean

 

[flyingpolarbear]

I use an APC UPS, around 300W, connected only to a 20W backup circulation pump. It helps a little when power goes out, but like the previous author, I believe the best solution is to have a generator on standby just in case. I like the Honda generators (2-3kW should be sufficient in most cases). They models 2kW and below are pretty quiet.