Recent content by toms

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    What are the top 5 gotchas for going totally off grid

    It’s becoming a circular conversation, no dedicated off-grid system that is designed from the start to power a typical house (20kwh/day) would have inverters that struggle to start any domestic pool pump. I haven’t setup a single inverter off-grid system for years. If the question is “how can...
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    What are the top 5 gotchas for going totally off grid

    How are you calculating the saving when you have an off-grid system as the OP is enquiring about?
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    What are the top 5 gotchas for going totally off grid

    I wouldn’t spend $1500 to save 6kwh/day. This thread is blending small (less than 20kwh/day), and grid tied system requirements with fully off-grid requirements. They aren’t the same.
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    What are the top 5 gotchas for going totally off grid

    That’s the theory. Build a few dozen off-grid houses with varying levels of insulation and then get back to me on how well that translates to reality. I’ve lived in a certified passivhaus building, and a tin shed (and a lot of levels in between). If you have constant air temp and...
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    What are the top 5 gotchas for going totally off grid

    There’s no such thing as lack of “headroom”. Any full sized residential off grid system (such as the one the OP is enquiring about) will include a fuel powered generator. The only point of interest is the cost of fuel over the lifespan of the system vs the extra cost of the energy...
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    What are the top 5 gotchas for going totally off grid

    Good answer for ten years ago. Like so many theorists, it would be wise to actually live off grid for a while in a variety of different scenarios before offering advice. Seriously, just build your off-grid house exactly the same as you would build a grid-connected house. Then install a...
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    What are the top 5 gotchas for going totally off grid

    Sure, but insulation has diminishing returns. The last 5% of comfort will cost 95% of the budget. Leave it at 95% and spend the rest on your power system. When it’s 50°C and in the full sunlight, how much do you think a window that will remain at less than 25°C on its internal surface would...
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    What are the top 5 gotchas for going totally off grid

    Show me the numbers. I’ve been through dozens of actual installs, and it’s only edge cases where spending dollars on extra efficiency beats spending dollars on your power system. How long have you lived off-grid, and what is your average daily usage? A good example of this is a neighbour if...
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    What are the top 5 gotchas for going totally off grid

    Most off-grid systems i build now have two completely independent systems. Don’t spend any extra on energy efficiency, put the money into your power system. Size your batteries for one nights maximum use only, and use generator power as required. That’s the main lessons i’ve learned from...
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    Super Capacitor Bank Output

    I have two systems for my house. The smaller one has a supercap in it to allow greater current than the battery specs for motor startups. This battery is connected to a large reverse cycle AC, a bore pump, and a desalination unit. It can run the rest of the house if required. The cost...
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    Are Lifepo4 cells sensitive to dirty DC ?

    The jury is still out regarding ripple voltage when DC charging. Initial projections suggested AC charging and the associated noise would shorten LiFePO4 lifespan, supercaps in parallel are used to mitigate the risk. In practice i haven’t seen anything to indicate a problem when not removing...
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    Batrium-experiences...

    And it looks like Batrium are happy to let you do business with them. I suspect their strategy in the field they are operating in will remain successful. I can see that there are a few that are unhappy, i’m another customer that moved to a different BMS as the Batrium was too complicated for...
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    Batrium-experiences...

    A company that is selling their products as fast as they can make them and has an overwhelmingly large percentage of happy customers isn’t going to waste someone’s time on edge case issues. It may turn around and bite them, but given the issues their competition has - i doubt it.
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    Winston lowtemp charge and more

    I have setup a lot of systems over the last decade using Winston cells. (they were the most popular LiFePO4 in Australia for a long time. Where i live minimum temps are -5°C. I set the systems to only charge above 0°C. Set your maximum charge voltage to 3.5V/cell, same as any other LiFePO4...
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    EVE identifies Grade B cells using new marking Method [Reposting from General]

    Sorry, meant capacity - when your 100% SOC becomes your original 80% SOC. I’m curious to hear of the cells that are still useful for a long time after this drop in capacity. The newer cells have better electrolyte than a decade ago, maybe they hang on for longer?
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