living off the electricity grid

[simonr]

Another option which I have used in the past is a computer UPS. Some use a single 12v battery. More of them are 24v - both of which lend themselves to being replaced by a bigger bank of batteries charged by something else.

Most UPS's make an annoying beeping while running off battery - but this is soon cured with a hammer! (to the speaker, not the UPS). The advantage as I see it is that you can charge your batteries off mains (generator) while available or from a low voltage source (solar, wind, Land Rover) the rest of the time.

The mains output, you can just treat as mains - they generally spit out a good enough quality sine wave for anything you want to run. Just buy one which has high enough capacity for what you need to run - 3kVA are fairly common.

eBay is a good option as you can as how many batteries it contains (to give you the voltage), info a retailer is unlikely to find for you. I doubt you'll find a cheaper solution.

Si

[bill van snorkle]

Thanks for all the information once again gentlemen.Their wasn't much reliable 12 volt equipment available when I last lived here some 7years ago. Not sure LED stuff even existed then either. next time I have to(dread!!!) go to the big smoke I'll check on most of the type of equipment you have all suggested.

My 140 A arc welder produces about the same quality welds as 3 12volt batteries, that for on vehicle repairs in awkward positions is very poor.Do Inverter welders require less amps on the input side for a given output than conventional arc welders? For reference if it's relevant,My previous 7kva generator used to run the welder just fine.

Bill.

[ejparrott]

Do you know, I havent a clue! Ive never looked at the specs for mine. It still runs off a 13A plug though, have a look at www.green3k.com for the Freeman 150a, the answer you're looking for might be there!

[FridgeFreezer]

Depending on budget, I'd look at a readywelder/spool gun. I've seen them produce some very acceptable stuff from 36v.

That reminds me - these days you can buy 12v (battery) angle grinders etc. which could also be worth a look. Anything 12v or 14.4v will be happy on a car battery. Dead battery powered tools are cheap (even free) when the batteries give up, just solder some leads to the battery terminals and stick croc clips on the end.

[redneck]

I lived off grid for over 7 years, on a converted trawler.

Our set-up involved a 2.5kva pure sine wave inverter (6.5kva surge capacity. very important)800Ah of 24v batteries.

100A charger and a 6.5kva lister genset. Where possible we used either 24 or 12 volt appliances (lighting, pumps etc).

For the heating we used a heating oil boiler converted to use red diesel, this heated our water and central heating with 240 electrics and 240v circulating pump (24 volt heating is available but nearly 6 times the price)

We used the inverter for most of time and charged the batteries when required with the genset(every 2 or 3 days), we did the washing etc when the genset is running.

The only thing I would change is, instaed of seperate inverter charger, you can now get inverter/chargers in one unit (as already mentioned), with automatic changeover.

You can run high output alternators with smart chargers to charge your batteries, but not ideal for day to day running off your landy.

I used to run the my 150A inverter tig set off my inverter with out any problems, but you do need a pure sine wave inverter.

BTW I know someone who has a domestic electric cooker on his boat running from two paralleled inverters, high output alternators and two small batteries!!!!!

Pm if you want any more info.

[Night Train]

Have you had a look at look at The Centre For Alternative Technology? They have many decades of living off grid and only recently acquired a grid connection as a means of storing their excess of electricity to stabilise their supply.

[ejparrott]

oh yeah - duh! Uncle works for them....