backchannel: a small car setup

From (a /r/urbancarliving thread](https://www.reddit.com/r/urbancarliving/comments/1bobas4/house_battery_setup/)

the setup

It will be running my fridge, a 500 watt induction cooker, electric water kettle, portable monitor. Used to charge laptop, phone, batteries for power tools, tablet and what ever else needs a charge.

some thoughts

This seems to be a thoughtful setup for inexpensive power. I took a Chemistry and aewsthetics of wine course as an undergrad in the late 80s. One quote sticks with me: “anybody can buy a good bottle of wine for $100; the trick is to find a good bottle of wine for $10”. I think OP has done a good job of it.

the DC-DC and battery

20A charging is spot-on the 0.2C charge rate used by many mfg to calculate cycle life. No mention of the car’s (miniman’s) alternator rating, but most should be fine at 20A. If not, this one can be derated to 10A via the LC terminal.

inverter and AC loads

The inverter seems a bit oversized for the bank. Assuming 85% inverter efficiency and a max 0.5C draw from the batteries our AC loads should be ≤545w. Our cooker fits under that; not clear about the kettle.

the cooker

[Note: the 500w induction hob sounds interesting. I suppose because of economies of scale the small ones can cost more than the full-power ones. We could just run full-power ones on LOW/MEDIUM but many of them pulse full power. This 500w model seems to be adjustable in 100w increments and I’d give it serious thought at $40.]

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