PDA

View Full Version : Back up batteries - emergency preparation



Disco Dan
11th July 2008, 13:09
Back up batteries - emergency preparation

You may of heard of people in NZ fitting solar cells to their homes and actually creating a positive amount of energy that they return to the grid.

You may also of heard of battery backup systems - where a battery bank is installed in your home and in the event of a power cut your appliances continue to run. This is along the same lines as a computer UPS but on a larger scale to run several/all home appliances.

Battery banks are relatively simple to construct, as well as a black out relay (http://www.alpharubicon.com/altenergy/2manytoyzblackoutswitch.htm).

The main things are the high cost of batteries and ensuring a way of recharging the battery bank. It is important to note that the wiring can get complicated!

So does anyone have a battery backup system installed already? How/where did you mount everything and where is the best place to get deep cycle batteries?

I'm researching ways in which to power a large aquarium, security system and also limited lighting (even computer). A standard computer UPS is simply not large enough power all of the items so I am looking into either a large battery bank located outside in a weather proof box and routing the wiring inside to the appliances.

Making a control box with indicator lights, override switches and meters.

Anyone have any experience with this sort of thing??

ManDownUnder
11th July 2008, 13:14
If it's only "non continuous load", buy a little generator and make sure the fuel's full.

Key start is good, remote start better.

Disco Dan
11th July 2008, 13:20
With the cost of fuel and the safety factors around storing fuel (treating it for storage and replenishing old fuel) the generator option is not really ideal. Especially when this system will be automatic - ie I don't want to be out/working when the power cut occurs and a generator fires up unattended!

I would prefer to be off the grid entirely however batteries are the next best thing!

I'm aiming for 8 hours use - when your standard UPS lasts only 1-3 hours I will be needing a lot of batteries I think!

However a small generator could well serve my purposes well - depending on how much fuel it would use. Ie - how much fuel I would need to store (inside) to power everything I want for upto 8 hours.

bungbung
11th July 2008, 13:24
Work out what your load will be first, go from there. You can buy pretty big UPSs, work out what size inverter you'll need and then how much storage you'll require for 8 hours.

Example: Std single PC UPS is around 350-450VA, if this can run your needs for one hour, then you'll require 8 x the battery capacity, simply replace the (probably) 7Ah batteries (s) with the eightfold equivalent. Should be several battery shops in AKL.

nodrog
11th July 2008, 13:25
..... and the safety factors around storing fuel...(

storing a heap of big batteries with dodgy wiring presents its own risks, make sure your smoke detectors are working.

Disco Dan
11th July 2008, 13:27
Well load wise this what i'm after -

Computer is easy 280w
Aquarium - x3 50w lamps, fluro tube (w?) filter (w?)
Lighting - one 100w bulb would be sufficient.

Roughly looking at at least 600w to be safe.

Disco Dan
11th July 2008, 13:30
storing a heap of big batteries with dodgy wiring presents its own risks, make sure your smoke detectors are working.

Yes very true, the web pages on battery storage I have found outline how to vent batteries and storage options etc.

ie - a kitchen cupboard lined with fireproof material, vented outside with fuses on the wiring.

Much prefer to have a cupboard full of acid filled batteries than cans of petrol/diesel !

nodrog
11th July 2008, 13:34
Yes very true, the web pages on battery storage I have found outline how to vent batteries and storage options etc.

ie - a kitchen cupboard lined with fireproof material, vented outside with fuses on the wiring.

Much prefer to have a cupboard full of acid filled batteries than cans of petrol/diesel !

beware if your house burns down (for whatever reason) and you have an uncertified mini powerstation under you kitchen sink, your insurance company might be less than helpful.

bungbung
11th July 2008, 13:37
Well load wise this what i'm after -

Computer is easy 280w
Aquarium - x3 50w lamps, fluro tube (w?) filter (w?)
Lighting - one 100w bulb would be sufficient.

Roughly looking at at least 600w to be safe.

You need to know your inverter efficiency, lets say 90% (according to Google), so 666W input for 8 hours = 5.4kW/h.

That is 441Ah @ 12V so you'll need 6 of 12V 80Ah batteries.

vifferman
11th July 2008, 14:03
So does anyone have a battery backup system installed already?
Mate, I don't even have the emergency bottle'o'water, can of baked beans, torch, radio, first aid kit...
If there's an emergency, I'll just hide in the wardrobe...

Morcs
11th July 2008, 14:53
Tropical fish can survive for a good few hours with no light or heat.

for security - just get one of those huge police torches and youve got a good weapon and a light :)

Calm down Dan, the germans arent coming.

vifferman
11th July 2008, 14:56
Tropical fish can survive for a good few hours with no light or heat.
So.....
I should eat lots of tropical fish?
(There's some good-sized goldfish in our pond, but I bet they taste like shit...)



for security - just get one of those huge police torches and youve got a good weapon and a light :)
Yeah, but I've got a few litres of mower fuel and some waste engine oil in the gargre - that'd be more fun for both purposes.

pzkpfw
11th July 2008, 17:07
If there's an emergency, I'll just hide in the wardrobe...


I'm planning to eat the neighbours.

vindy500
11th July 2008, 17:20
if your power goes out it doesnt really matter if your tanks lights turn off, just make sure the heater and filter keep going

scracha
11th July 2008, 18:05
I've got 3 x 650Va UPS's (they're under $100 each) connected in a serial type fashion. A genny is on the todo list (be useful at the track too). Otherwise you're getting a sparky in and spending lots of peso's. After investing lots of peso's, be aware that the batteries wear out in a shortish period of time.

Why on earth would you wanna keep the computer going though :shifty: Buy a laptop and some spare batteries for it.

dhunt
11th July 2008, 18:49
Back up batteries - emergency preparation

You may of heard of people in NZ fitting solar cells to their homes and actually creating a positive amount of energy that they return to the grid.

You may also of heard of battery backup systems - where a battery bank is installed in your home and in the event of a power cut your appliances continue to run. This is along the same lines as a computer UPS but on a larger scale to run several/all home appliances.

Battery banks are relatively simple to construct, as well as a black out relay (http://www.alpharubicon.com/altenergy/2manytoyzblackoutswitch.htm).

The main things are the high cost of batteries and ensuring a way of recharging the battery bank. It is important to note that the wiring can get complicated!

So does anyone have a battery backup system installed already? How/where did you mount everything and where is the best place to get deep cycle batteries?

I'm researching ways in which to power a large aquarium, security system and also limited lighting (even computer). A standard computer UPS is simply not large enough power all of the items so I am looking into either a large battery bank located outside in a weather proof box and routing the wiring inside to the appliances.

Making a control box with indicator lights, override switches and meters.

Anyone have any experience with this sort of thing??
1) Get some old telcom exchange batteries or buy some truck lead acid batteries. Hook a few in parallel to increase storage space.

2) Buy a decent size inverter - 1k-2kW is probably pretty good. An average a house uses about 1kW if I remember right. Keep the wires to your inverter short & use large gauge wires to lower losses in wires.

3) For higher efficiency (less losses) run stuff straight off the 12V system if you can. ie lights, power packs etc.

4) Replace all incandescent lights with fluorescents.

5) Get rid of your desktop and buy a laptop to save power.

Just remember if you get lots of cloudy days/our current weather. Solar panels will not make as much power. So you will need to reduce your load in these cases.

For example when I was growing up we just had solar power. We ran 4x 60w panels for our fridge (high efficiency super thickwalled 3-4"). Which after 3 days of bad weather would turn off.

The rest of the house ran off another 4x 60w panels. All our lights were 12V high efficiency fluorescents. We ran as much as we could off 12V. Computers/laser printer ran off an inverter. If we had a few days of bad weather we had to limit computer usage and limit number of lights on simultaneously.

Hopefully that gives you some ideas.

Swoop
11th July 2008, 20:06
The "sending excess power into the grid" thing is being attended to. A lot of the old type of meters (with the wheel that goes around, and around, and around...) are being replaces with digital ones. I am led to believe that you cannot "back feed" power into the grid with these (and get paid for it of course).

CookMySock
12th July 2008, 11:02
Computer is easy 280w
Aquarium - x3 50w lamps, fluro tube (w?) filter (w?)
Lighting - one 100w bulb would be sufficient. Turn the PC off and boot teh lappy up 280w becomes 21w. Dont use 100W incandescent lamps - use an LED equivalent - 100w becomes 4w.



be aware that the batteries wear out in a shortish period of time. Just replace them with some car batteries.

DB

FROSTY
12th July 2008, 11:25
Currently my parents house is 100% self sufficient electricity wise. -has been for a number of years.
For lighting/tv etc they have a bank of deep cycle batteries which are stored outside under the deck.
To charge it up they have a bank of solar panels with a windmill backup unit.
Refrigeration is by lpg
water heating is a combination of wood stove wetback and solar
cooking is either lpg stove or woodfire