Jump to content
Sign in to follow this  
agent_zed

Wiring A House With 12V Leds From A Battery

Recommended Posts

ok so this is probably a stupid idea but bare with me..

 

So my Fiancee likes low light levels before bed as it helps her get to sleep. My problem is that i don't have that type of light in my house as i've just installed loads of downlights. So i could always put dimmer switches on but i don't really like them as i can often hear them buzz (thankfully the 2b hasn't killed my hearing yet) and i don't really like them in general as the button is harder to operate quickly (yes first world problems).

 

So in the bathroom i've already made a solid oak shelving unit that has 12v strips of leds under the shelves which i was going to run off a 12v transformer but then i got to thinking.... :crazy:

 

I have 4kw's of solar panels which merrily make electric during the day, most of which i don't use. But what if i was to store some of that for later!? but how...? a car battery in the garage with a charger set to come on during daylight hours.

 

Surely this would be enough power to run a fair few led strips wouldn't it for quite a few hours?

 

On the practical side if there was a powercut i would still have lights and also my hot water uses a pumped heat exchanger from the tank which i could for a short time run an inverter off the battery (it only has to run a small circulation pump) and it would cost me nothing to run the lights.

 

Is this a ridiculous idea?

 

 

Share this post


Link to post
Share on other sites

Not a problem in my eyes, we wobble box pullers use 12v led's, water pumps, toilet flush etc. running from a battery being charged by either a mains supply charger or from a solar panel on the roof.

 

We spent all weekend at Stoneleigh this year off our solar panel, using water pump for showers a little bit of TV and lights as and when needed.

  • Like 1

Share this post


Link to post
Share on other sites

12 volt LED strips in all your windows behind pelmets would give a natural wash of light down the curtains or window panes, could run all the L/V wiring round the outside of the house making for a simple installation (assuming detached property)

 

LED strips I've used come in 5M lengths which can be cut at every 3rd LED & connect direct to 12volt DC.

Share this post


Link to post
Share on other sites

Us yachties have exactly the same..all my lights are 12/240v for use on mains supply or away on the battery. Battery gets charged via engine alternator/solar/from 240 mains

Share this post


Link to post
Share on other sites

Would require deep cycle batteries if you want them too last a long time, car batteries are designed to give a big instance load of current then be topped up, where you require long charge time and long current drain, as a short term solution a car battery would work.

 

When setting up battery size, length of time lights will be on for X current draw off lights will = X, is dose not mean you need X as the battery size, X is your float value which is about 20% of the total battery (depends on batteries),

 

so you had 2 amp draw on lights and you would have them on for 2 hours, you require 4 amps to run them, so not to destroy and shorten the life of you batteries you will need at least a 20amp battery.

 

but this will only allow for 1 day, during the winter this would cause a problem as lack of light to charge the batteries, As I don't know your set you whether your using a gird tie system or a back feed system. deeming how much solar to point to the battery's depends of type and voltage arrangement of your solar set up but a good rule is 20% to 50% of the power of panels generated in winter time.

 

If it was me and you had a 12v solar rig, I would point all of the solar panels at the batteries allowing you to use a smaller size battery then use a charger controller to divert the solar panels back into the house once the battery's are fully charged. This means you keep the battery's toped up and once there full it goes back into the set up you have at the moment.

Edited by owlman

Share this post


Link to post
Share on other sites

Yes, I have a couple of 100w panels charging leisure (deep-cycle) batteries through a maplin solar-panel to battery charger. In the evening I run an inverter to power the TV - but if you have 12v LEDs, you wont need an inverter.

I had to upgrade one of the batteries to a large lorry battery so that on a hot sunny day like today it could store all the electric generated. It then runs the 40" TV for 4-5 hours in the evening.

As an initial test, I used old car batteries (old but not dead) because the inverter turns off before the battery is completely flat. Again with LEDs you wont get this option.

-steve

Share this post


Link to post
Share on other sites

sounds like a brill idea as said maplin do strip led lights I have them under the wall cupboards at night they are the only lights we need we also have led flood lights out side that are 12/240v so you have got me thinking along the same lines

peter2b

Share this post


Link to post
Share on other sites

Thanks for all the thoughts. I am more convinced to do it now. I'm renovating and have most of the ceilings down and/or have access under the floating floor so running wires is not an issue. I have a 4KW solar system so having a battery charger come on for daylight hours is not going to take a lot of juice to charge the battery is it?! I don't have my charger to hand but i can't imagine they use more than a couple of hundred watts do they? I guess as well as a leisure battery i need a 'clever' battery charger that knows when to stop charging. http://www.halfords.com/workshop-tools/garage-equipment/car-battery-chargers/halfords-fully-automatic-battery-charger?cm_mmc=Google+PLA-_-Garage+Equipment-_-Car+Battery+Chargers-_-329075&_$ja=tsid:60494%7Ccgn:GoogleShopping%7Ckw:329075&istCompanyId=b8708c57-7a02-4cf6-b2c0-dc36b54a327e&istItemId=aiwrritl&istBid=tztx&_$ja=tsid:35522|cid:344535484|agid:25437357364|tid:pla-224048583844|crid:89797547524|nw:g|rnd:1976181046310988246|dvc:c|adp:1o5&gclid=CjwKEAjwrvq9BRD5gLyrufTqg0YSJACcuF81h7zOzavhd_ZV0g233qB5clQx3tAMOMv9RSYvqJD0BRoCzL7w_wcBthis one for example seems to suggest it will sort itself out between full charge and trickle. I'll just put it on a timer plug for daylight hours.

 

might be a while before i get this set up though

Share this post


Link to post
Share on other sites

hahaha 365 days of christmas? might get in the way a bit in the house.

Share this post


Link to post
Share on other sites

have you given fork truck battery's a thought

 

can't say i have :)

 

Are they 12V? Lorry batteries are 24v aren't they?

What are the advantages of fork truck batteries?

 

I'll probably start with a car battery as i have a couple of ok-ish ones kicking around the garage and i don't mind if i kill them whilst experimenting.

Share this post


Link to post
Share on other sites

Truck batteries are 12v mounted in series to go up to 36v when such is required.

Truck batteries would be better than car batteries as higher wattage or amp/hours.

However as quoted by deep cycle batteries made to do this kind of job for caravans, boats, barges etc are the best type for you to get.

Normal batteries are designed to be charged as getting used so the voltage does not keep getting to low.

Deep cycle batteries will live a lot longer in your case as they are able to take continuous use to low voltage and then recharge when convenient. Only downfall is they are more expensive.

Whatever you do, do not go Li I. Don't know if you are aware but in any application the are allowed to go completely flat, they will not recharge and so are completely us.

Anyone with one fitted to your car should disconnect it when car not in use.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...