# Electrical Question: Choosing batteries to power low-voltage lighting

#### imported_Pablo

##### Diamond Member
BACKGROUND

My family owns a cabin in the mountains that is 1 mile off-grid.

I am researching lighting solutions. We currently light the cabin with coleman propane lamps. Needless to say, these are high maintenance, only last a few hours, etc.

I read an article recently in Dwell magazine about an off grid house that used halogen lights on a wire track to provide power from a deep cycle battery. I'm trying to figure out if this is a possibility.

PROBLEM

I'm looking at sealed batteries right now due to ease of maintenance, specifically, Optima Blue Tops (deep cycle). Their specs are here.

I'm looking at a cable light system here where each light draws 20 watts.

I will not be using the transformer.

My question is, how do I calculate how long one battery will power one light, two lights, ten lights, etc?
Anybody offer any help? Thanks in advance!

#### MikeyIs4Dcats

##### Lifer
a small generator would be a much more sustainable option.

#### oynaz

##### Platinum Member
Watts = volt x ampere.

#### imported_Pablo

##### Diamond Member
Originally posted by: MikeyIs4Dcats
a small generator would be a much more sustainable option.
We have a generator. They are noisy. Cheap ones don't last long, good ones are expensive.

#### Mo0o

##### Lifer
what if you use LEDs? Wouldn't that require much less energy?

#### imported_Pablo

##### Diamond Member
Originally posted by: oynaz
Watts = volt x ampere.
12 volts x 1000 amps = 12000 watts... but for how long?

#### SoulAssassin

##### Diamond Member
Originally posted by: MikeyIs4Dcats
a small generator would be a much more sustainable option.
Would it be efficient to use a generator to occasionally charge the battery to power the lights? This way if you don't need to run the generator all the time and you still have battery power at least for a while if you forgot to fill up the gas tank.

Also, depending on your budget and how long you/your family is going to own the house is solar an option?

#### imported_Pablo

##### Diamond Member
Originally posted by: Mo0o
what if you use LEDs? Wouldn't that require much less energy?
It might, I haven't researched them, but I would still need to know how long the battery would last....

#### So

##### Lifer
Originally posted by: MikeyIs4Dcats
a small generator would be a much more sustainable option.
I tend to agree. Gas is cheaper per watt than batteries and you won't have to take the batteries home to charge, just an empty tank.

#### imported_Pablo

##### Diamond Member
Originally posted by: SoulAssassin
Originally posted by: MikeyIs4Dcats
a small generator would be a much more sustainable option.
Would it be efficient to use a generator to occasionally charge the battery to power the lights? This way if you don't need to run the generator all the time and you still have battery power at least for a while if you forgot to fill up the gas tank.

Also, depending on your budget and how long you/your family is going to own the house is solar an option?
Solar isn't an option, due to a heavy tree canopy, but I have looked into microhydropower. Plenty of water flowing thru the property.

But my main concern right now is how to calculate how long the lamps would operate on battery power. Any help?

#### imported_Pablo

##### Diamond Member
Originally posted by: So
Originally posted by: MikeyIs4Dcats
a small generator would be a much more sustainable option.
I tend to agree. Gas is cheaper per watt than batteries and you won't have to take the batteries home to charge, just an empty tank.
Maintenance on an occaisional use generator isn't easy. Oil would need to be changed etc. Keeping fresh and charged batteries would be much simpler for my father as opposed to maintaining a generator.