Pure or modified inverter

[Dicko1]

Not quite, at full power it will draw 1000/12 = 83amps and considering you don't want to run the battery down under about 50%, you have about 40 minutes of useful time if on one 100amp deep cycle battery.

Inverters are not very efficient. Allow 10-15% inefficiency loss. A 1000 watt piece of equipment would pull about 100amps from a battery at 12 volts. Depends also on cabling and resistence. So a typical start battery of 80amps would last about 20 minutes before its longevity will be harmed. A 100 amp agm would take 30 minutes and then approach the 50% limit most people abide by for battery longevity. If its a very rare occurrence then taking it down to 30% is possible with no long term damage. This is why we try and use 12 volts for all our camping equipment...tv,s, laptops, drills..etc.

[Drewan]

Van has 480 amp hrs gives us about 4 days living normally with no sun (fridge is on gas , fire makes things cold who knew ) was a shipwright in my youth got used to giving wives what they wanted so husband's could have their toys . Don't get put off by high output inverters . a 1000w inverter with a 500 w load will use a lot less amps than a 600w with a 500w load its a swings and roundabouts kind of deal (hurts my brain as well )

[Poita]

General rule of thumb... Divide the power of the ac device by 10 and that will give the approximate dc current required from your battery. Inverters are typical only 85% efficient.

[Kingbrown]

Also worth noting that a typical lead acid battery rated at (say) 100Ah at a modest C10 discharge rate will have a significantly reduced capacity when it's called on to deliver energy at a hefty C1 rate (or greater).

[Ian H]

Agree with the posts above.

. a 1000w inverter with a 500 w load will use a lot less amps than a 600w with a 500w load its a swings and roundabouts kind of deal (hurts my brain as well )

A 1000W inverter with a 500w load will still draw around 50amps (using the divide by 10 rule - which is a worse case scenario, it's actually divide by 12).

I think most equipment which would need that much power would be things like a heater. But that's negated because there's no point running one for only 30 minutes, or 60mins if you have 2x100 batteries. Coffee makers also pull that sort of power and don't run for long but that's a lot of dollars for a decent cuppa. Hair dryers....we have a 12v. Cryovac machine, ditto. Toasters, you can do it on gas, same with a kettle. A microwave oven is all I can think of and that's a maybe as they draw more power than they output.

What have I missed ?

[Drewan]

After much trial and error we've found our microwave makes a great place to store bread 😀

[Bru9]

You can't do anything really with a MSW inverter, they are almost useless unless your running a light bulb or a toaster. Even ac adaptors in laptops & ac fans really should use PSW. You will not get a solid answer as to whether your appliance can run on MSW unless you try yourself.

I just got a small PSW for my 30cm AC ped fan, as there is no DC fan that will cool you down. Sure it uses more power but at least it sounds quiet & oscillates. That is the thing you need to understand that many DC appliances are plane bad compared to AC household ones.

Another thing is the size of battery bank has to be truly massive to run large inverters like 1000watts +. My 130AH AGM battery pack can really only take about 200-300Watts max for continuous use.