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0 pointsmschuster914mo ago0 comments

> I guess the bigger issue is the limited power -- you probably can't use a small scale solar installation for cooking or washing, not because it's DC, but because it just wont offer 1000W power.

Your average lead-acid starter battery can easily do that - 1 kW is less than 100 amps at 12V, less than 50A if you wire two in series. 200 Ah means about four hours worth of runtime.

The problem is switching off higher DC voltages and currents. AC is easy, it traverses through 0V 100 (or 120 in the US) times a second. But DC? The arc is just going on. That's why most electrical equipment, from switches over automated breakers to fuses, has distinct ratings for AC and DC, with DC ratings sometimes being half the AC rating.

Additionally, larger DC networks tend to have issues with weird current flows and electrochemical corrosion.

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nativeit4mo ago

Could it easily do that for several minutes at full chap? Under the load of a full washing machine?

kragen4mo ago

No, only for about a minute or two. But there are a lot of lithium-ion batteries capable of 10C discharge rates which can survive several minutes of max load. For 100 amps I am guessing you'd need 10 amp-hours of 10C-capable lithium-ion batteries, roughly a 4S4P or 4P4S configuration of 10C 18650s. I think this is about US$128 of batteries, a similar price to the car battery but much smaller and more inflammable.

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