Changing to 12v lighting

Rouxenator

Rouxenator

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Going all out solar is going to be too expensive to me, that I have made peace with. What got me thinking is pretty much all my lights are 12v downlights, each with their own transformer. Assuming I have about 40 of them in the house and each are max 6watt I should be able to run them all off a single rather powerful USP? At least 240watt.

I was thinking of just getting a large UPS and running them off the battery. If there is AC power the UPS will charge the battery even as they are running off it and when the power goes they will just keep running off the battery. Is there anything I should consider or take into account on this?
 
No reason why it shouldn't work. Watch that whatever is charging the battery doesn't output too high a voltage tho.

240W is 20 amps, add another 5 in for inefficiencies, so at 25A constant draw you'll need a 100AH battery to last the 4 hrs. Get 2 if you want the batteries to last.

EDIT: for whatever is charging it's gonna have to charge at over 20A if you run the lights while the battery is charging. Quick google shows that a 40A charger to charge in 4 hours while all lights are on is 3k, and about another 3k for the 2 batteries...
 
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Rouxenator said:
Going all out solar is going to be too expensive to me, that I have made peace with. What got me thinking is pretty much all my lights are 12v downlights, each with their own transformer. Assuming I have about 40 of them in the house and each are max 6watt I should be able to run them all off a single rather powerful USP? At least 240watt.

I was thinking of just getting a large UPS and running them off the battery. If there is AC power the UPS will charge the battery even as they are running off it and when the power goes they will just keep running off the battery. Is there anything I should consider or take into account on this?
Click to expand...

If you are planning to go that far with rewiring - why not look at replacing the lights with LED DC units? That will probably cut your demand by 50%
 
Im a little confused. You saying your requirement is just 240w but yet you want a large UPS ? Generally a large UPS means 3kw + .
 
I have 22 bulbs in my living room running at 40w each...

a 3w Arora candle bulb is going to cost me R215 each...

I am looking for something similar to OP to run all the lights in the house as well.

So what components would we need?

I pretty much suck with these things. :)
 
You could do this with any lights... This setup is just going to go 220-12-220-12 a normal light will go 220-12-220... it's just the wattage which is the problem. Or are you planning on doing away with the transformers and pushing 12V through your house? This would be a bad idea as you are basically multiplying the current in your house by 18x and with heavy losses.
 
ScottulusMaximus said:
EDIT: for whatever is charging it's gonna have to charge at over 20A if you run the lights while the battery is charging. Quick google shows that a 40A charger to charge in 4 hours while all lights are on is 3k, and about another 3k for the 2 batteries...
Click to expand...

You wouldn't be running the lights 24/7 so a decent capacity UPS could trickle charge through the day and then come on when you need it at night.
 
It depends if he's going Charger---Battery---Lights all at 12V or UPS---Transformers---Lights.

Case 1: you have to have a charger that runs at higher than 20A or will discharge continuously while lights are on.
Case 2: will need an inverter rather than a UPS to handle the bigger batteries
 
The LED lights are already 12V downlights, each with their own transformer. Simple replacing the transformer and running it off a large UPS should provide hours of light?
 
ScottulusMaximus said:
It depends if he's going Charger---Battery---Lights all at 12V or UPS---Transformers---Lights.

Case 1: you have to have a charger that runs at higher than 20A or will discharge continuously while lights are on.
Click to expand...
Yep, that is what I am aiming for. Going 12V DC on the light circuit for the entire house.
 
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