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.

 

[The Ghost]

i changed my mind 3 times on which room

I've worked for you before I'm sure, maybe not just seems familiar that thing about changing your mind halfway through an install.

 

[Marvo]

You're welcome. I see you can buy 10 watt 12VDC floodlights on ebay for under five UK quid and the LED strip light is less than 10 quid per 5 meter length which is pretty cheap. I assume similar is available in France if you shop around so you should be able to buy back-up lights for the entire house for about 50 Euros.

 

[static zap]

.... i do like the idea of LED lamps

Probably the right kind of current , (My old favourite was a small 12V fluorescent...)
Car batteries -hate deep cycle ,so cannot get near AHr rating (even nearly new) with steady loads !

 

[pirate]

Indeed Static, which is why I use the golf trolley batteries which are deep cycle, and likely to be virtually fully discharged every round, then charged up again for my next attempt at breaking 100...and that's just on the front nine!

They are also very compact, about 9" square, and 3" deep, so very portable. ( i believe they come in metric sizes too!)

 

[pirate]

Here's the metric version

18cm x 18cm x 8cm

 

[Marvo]

Yep, golf cart batteries would be deep cycle as would fork-lift batteries, both would be suitable but I found that batteries made/marketed for a specific purpose were inexplicably more expensive that a general deep cycle battery of exactly the same specification.

The cheapest decent quality deep cycle batteries I could lay my hands on at the time were Trojan T105 which are a wet lead acid type. I installed 4 of them in series to give me the 24VDC that the inverter required. I've had them now for about 4 years and they've seen about 200 full cycles and maybe 25 partial discharge cycles and they're still in great condition. We had a planned power outage the other day that was for 6 hours and the system ran the entire time and still had about 30% left in reserve when the power came back on. Finger crossed they last another 4 years without problems.

 

[pirate]

Good info there, thanks Marvo!
To be fair, I thought the OP was looking for a simple, compact and cheap way to get some light when the mains failed for a couple of hours...
now I think she could run a call centre on a PP3!

 

[static zap]

(...Was PP9 the bigger one for fake Wooden Fidelity radios ? --Blast from past)

 

[pirate]

Yup, PP9 was the big fella! Think it had 2 spring terminals. Heavy beast ...

 

[Adam W]

Yup, PP9 was the big fella! Think it had 2 spring terminals. Heavy beast ...

The "lantern battery", which I remember from my youth is what they used in those flashing beacons they have on roadworks.

 

[pirate]

Think I'm getting confused...
the PP9 had snap terminals like the PP3
this is the chap with the springs...

and is the "lantern" type, iirc...
I had a flashlight that took 2 of these. It was very heavy, and very bright for about, oh, 5 minutes, before it started to dim. Things have come a long way with battery technology and LEDs!
PP1, PP7 and PP9 were all 9v with snap connectors.
There was another one, which was rectangular, and had screw-on connectors but I cannot recall what it was called.

 

[pirate]

Well, clearly I am at a loose end today!

 

[pirate]

"There was another one, which was rectangular, and had screw-on connectors but I cannot recall what it was called."
Oh well, here you go...it was also called a lantern battery.

 

[Adam W]

Bit before my time but you used to need a dual voltage 90v/1.5v battery to run portable radios.
According to t'internet they stopped making them in the 60s.

A decorator I used to work with found one in his shed. It had a battery clip on it so I tried to get it working by sticking 10 PP3s together, but let the smoke out.

 

[static zap]

Ahh memories tongue testing batteries ,3R12 - 4.5V
with long and short brassy strips ..friendlier than PP3 !
(3R12...May be new name .. )