My boiler needs replacing, I need to re-fit the kitchen, I need new double glazed windows and I need to re-decorate throughout the house. Got no hope of starting any of these jobs until I can organise space for the bikes currently dotted around the house. This is going to be a Tuin log cabin/shed at the bottom of the garden and in the short term I need some sort of temporary 240V AC power until I can arrange for a permanent feed from the existing garage ring main. Welcome to the world of the 12V DC inverter only nothing I have found on the internet so far explains in layman’s terms how best to provide constant power for small current stuff like battery maintainers and switchable power for the heavier current users like the air compressor and MiG welder. I have a 3kVA camping generator that puts out 12V DC but not enough 240V AC amps and I have several Class A 1100 Whr batteries from my folding camper days. Anyone out there who can give me some insight and please remember, I am (or was during my working career) a mechanical engineer Andy
I just put a new 1000w pure sine wave inverter in my motorhome, £180, came with appropriately sized leads. Its hooked to 2 x 12v 110 Amp heavy duty, good quality leisure batteries, about £120. The system is charged in 3 ways, off the vehicle when running, off the mains when hooked up with a shore line or off the 150W solar panel when it is sunny. The general rules are: if you are planning on running anything sensitive then you must go pure sine wave as opposed to modified sine wave as the latter can cause problems. Figure out what you will be running/charging, take the "start-up" requirements for it and double the wattage on your proposed inverter as large items such as microwaves, drills or hairdryers can have double the starting current draw as they do when they are operating. If you go down the battery bank and want independent operation at locus I would suggest a solar panel on the roof, run it to a controller and run a battery bank off it and then install your inverter. However, if you are running heavy stuff off an inverter supplied by a battery bank, ie a compressor, you are going to suck the batteries dry sharpish; so you would need to beef up the system. Big inverters, the panels to charge them and the bigger batteries to supply will get pricey. Maybe just bite the bullet and fit a mains system. Cheaper in the long run. There is a lot of assistance out on the tinterweb on all this, especially on MH, camper,boat etc sites. Hope this helps.
Brilliant, thank you. This is a temporary solution because my property has a boundary with an electricity sub station and several 440V supply cables run under areas of my garden. Running an underground, armoured supply cable is my preference in the long term but I have to liaise with SSE which is a time consuming process. Andy
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I also meant to say that AFAIK you wouldn't be able to run a welder off a battery bank supplied by an inverter, the draw wuld be massive!
I’m good for a battery supplier, had to look after a string of mobility scooters that my late sister insisted she must have over the years. Andy
Accept that which is why I said I’ve got a portable generator which usually runs the tyre warmers and a small kettle. Not man enough for the welder but it has a fairly high current supply 12V DC output. Andy
NP Andy, I'm doing my van to a camper atm. Ive done the leisure battery install and electrics. My next task is exactly this. The electric hook up and inverter etc, just waiting till Ive had the pop top and the bed installed. (once i can get to book the bus in)
Rather than faff with batteries, inverters etc, run a temporary cable to the shed, a length of suitable cable wouldn't cost much, considerably less than an inverter
That’s what I thought. As much as I like the idea of solar and or a storage system, they are long long term solutions. As Ivor suggests it would be far cheaper to run a temporary cable overground. You must have some reason though.
