running a house from car batteries for the electrical idiot

[ellie]

No, if you know your 12v electrics, there is zero fire risk if, and only if, you do your homework, so on this occasion I beg to differ Vortigern.
I was born and bred on these 12v things, and 24v too, and there is no way you can cause death by stupidity unless you add total ignorance too!
It is a different world, and it has it's detractors, but the fact remains...some install sub-stations, some do mini-electrics, but each has its idiosyncracies, and each its specialists!
So..."electricals/idiots"? well probably not...but I bow to your experience...

phew! momentary panic over. lol.

 

[ellie]

No, if you know your 12v electrics, there is zero fire risk if, and only if, you do your homework, so on this occasion I beg to differ Vortigern.
I was born and bred on these 12v things, and 24v too, and there is no way you can cause death by stupidity unless you add total ignorance too!
It is a different world, and it has it's detractors, but the fact remains...some install sub-stations, some do mini-electrics, but each has its idiosyncracies, and each its specialists!
So..."electricals/idiots"? well probably not...but I bow to your experience...

phew! momentary panic over. lol.

No, can't say I have lol. Seen a few go up though.
I don't think the OP will be commissioning this herself though. I think she is just looking for views.

um... i will be doing it myself. i did all my house wiring, plumbing, windows, flooring (tiled and wooden) myself. as well as digging a soak-away cesspit, digging a swimming pool and many other things. with each job i took on i had no idea of what i was doing so i asked everyone i knew and many i did not for their advice. the first time i plumbed in the bathroom (i changed my mind 3 times on which room i wanted it in) i had my phone clamped to my ear with my dad on the other end talking me through what to do. ok, so i am crap at soldering joints to i bought compression joints instead. et voila! a higgedly-piggedly, oddly routed water system that works and does not leak. lol luckily i have lots of time and am not too bothered if i make mistakes. as long as they don't kill me. OH! i did nearly die once. i sawed through a 3-phase cable that was supposed to have been disconnected years before i bought the house. my saw now has 3 inches of teeth missing. and i lost a potentially free source of electricity. i am so glad i had wellies on and gardening gloves

 

[ellie]

Have you ever tried putting a spanner over the terminals of a car battery? But yes on the surface of it what could possibly go wrong. Oh and by the way I would not recommend bowing to my experience, like anyone else here there are always things to learn from each other.

no. but now i am ... brb

 

[Marvo]

I still have a very basic back-up system at home, it's something I installed a few years ago when we were have power outages of 3-4 hour duration on alternate days.

Firstly forget halogen lighting of any kind, they're a fire hazard, they're fillament so they're unreliable and they're extremely innefficient. Use LED lights.

Secondly forget car batteries or any normal lead acid batteries, they're not designed to be discharged by more than 20%, discharging them more than that destroys them in no time (<a month) You have to use deep cycle lead acid batteries, yes they're more expensive but they should last years rather than days.

Because we were getting the power back on every day solar wasn't worth the extra expense. The cheapest route for me was a small, cheap 5kVA inverter that was plugged into the normal supply and 4x lead acid 110Ah deep cycle batteries to provide back-up power. .

The inverter ran all the important items in the house such as 3x PC's, 1x server, ADSL router, cordless telephones, TV, satelite decoder, Hi-Fi system, as well as occasional use of microwave, kettle and coffee machine. On batteries it would run for around 5 hours with everything on and about 7 hours if I shut things down when I wasn't using them.

I also installed some 12vDC LED lighting around the house, it was mostly cheap 10 watt floodlights and some adhesive tape type lights. Obviously the lights ran directly off the batteries, not from the inverter.

 

[ellie]

BTW, we always tested the calor cylinder to regulator joint with a match!
Oh, happy days!
DO NOT DO THIS FOLKS!
(It's fine actually, as long as you ventilate the area properly...
50 years on and I'm still here...and the copper junctions just had an olive and a smear of calor-tite and that was that...of course we ran a risk assessment every time we changed a cylinder!)

a friend of mine who used to work for the gas board told me that is exactly what he used to do. i was horrified and wondering if he was pulling my leg all at the same time.

 

[Marvo]

As mentioned it is worth putting a main fuse at the batteries and it's also worth fusing any 12vdc circuits you run. Without fuses the risk of fire is very high.

I'll add a few photos of my setup but I'll warn you in advance it isn't going to win any awards...

 

[ellie]

Maybe she will even revert to us and tell us what she has done...

she will. and probably add a few photos too. I have thoroughly enjoyed reading all the posts this evening and have learned a lot in an interesting way.

 

[ellie]

Why can't the OP just use mains electric,and just do what the French do,when something fails,and they are not happy with it...block the roads and have a picnic

i have mains electric. for the most part. but power cuts are a fairly regular occurrence. especially in the winter when the wind blows trees down. more than happy to have a picnic though.

 

[ellie]

I still have a very basic back-up system at home, it's something I installed a few years ago when we were have power outages of 3-4 hour duration on alternate days.

Firstly forget halogen lighting of any kind, they're a fire hazard, they're fillament so they're unreliable and they're extremely innefficient. Use LED lights.

Secondly forget car batteries or any normal lead acid batteries, they're not designed to be discharged by more than 20%, discharging them more than that destroys them in no time (<a month) You have to use deep cycle lead acid batteries, yes they're more expensive but they should last years rather than days.

Because we were getting the power back on every day solar wasn't worth the extra expense. The cheapest route for me was a small, cheap 5kVA inverter that was plugged into the normal supply and 4x lead acid 110Ah deep cycle batteries to provide back-up power. .

The inverter ran all the important items in the house such as 3x PC's, 1x server, ADSL router, cordless telephones, TV, satelite decoder, Hi-Fi system, as well as occasional use of microwave, kettle and coffee machine. On batteries it would run for around 5 hours with everything on and about 7 hours if I shut things down when I wasn't using them.

I also installed some 12vDC LED lighting around the house, it was mostly cheap 10 watt floodlights and some adhesive tape type lights. Obviously the lights ran directly off the batteries, not from the inverter.

thank you. i like this idea. do you have any advice about selecting an inverter please? or do i just chose one inside my price range?

 

[ellie]

thank you to everyone who took the time to reply to my question. i have found all your replies to be most informative. i am so glad i found this forum. i hope you do not mind me popping in again when i have more questions. and i will.

 

[Marvo]

I'm not sure what inverters are available in France, the one I used was an 'Axpert' but I've seen it rebranded under other names as well. It was pretty cheap as pure sine inverters go and it's been very reliable.

Here's the battery bank, you can see the main fuse at the top right and also one the lighting circuit fuses laying loose on the left if you look carefully

Here's the inverter (the silver box in the corner);

 

[Marvo]

I ran the back-up power from the inverter on extension leads. Here's the lead that powers the coffee machine and above you can see one of the 12vDC 10 watt floodlights that's powered direct from the batteries.

 

[Marvo]

This is the LED tape lights I used in the kitchen;

And this is what they look like when they're on;

 

[Marvo]

This was another 12VDC floodlight that provides back-up lighting in my office, it was just a plain light so I added the pull switch.

As I said it's not going to win any awards but it served it's purpose when we had regular blackouts.

 

[ellie]

This was another 12VDC floodlight that provides back-up lighting in my office, it was just a plain light so I added the pull switch.

View attachment 41451

As I said it's not going to win any awards but it served it's purpose when we had regular blackouts.

Wow. thank you for the pictures. that is really helpful. and those LEDs look brilliant (literally). Thanks Marvo. much appreciated.