What, if there is one, is the conversion between AC and DC amps?

[max2k]

greetings all, first post. be patient.

I'm looking over the spec sheet of the tesla powerwall and it's boasting 14 kWh @ 50V. The aH doesn't seem that different than other batteries, but I'm confused on the 14kWh capacity. Is there a conversion between AC and DC amps they are using to claim 14kWh will run a 2-bedroom abode for a x period? I know, I know, it depends on watt hours, but it just seems like an inflated claim until I know the method used.

I'm just getting started--looking at a way to combine a small 2-axis array with a portable gas gen to weather the outages we've had here in Houston during the storms. "burst" generator usage and some simple battery storage to keep two fridges running about 7 hours each day and periodic use of one HVAC (and some random LED kitchen lights).

But, amp conversion--the impetus for the post.

thanks, and I'm researching the archives now too.

it's defined by the law of energy preservation: AC energy = DC energy + some losses (< 5%) Now if you have 14,000 Wh of energy such storage can power 1 kW load for about 14 hrs. If DC energy comes from solar typically 5hr are taken as charge time so to supply 14kWh of energy one needs 14,000Wh / 5h = 2,800W of panels to fully charge that battery. Normally you would want to use about 1/3 of your battery storage daily to have at least 3 days of autonomy so it can power 1 kW load for only 5 hrs and subsequently would require only 1 kW of solar panels to replenish. As you can see amperes were not involved in these calculations at all. HVAC often defines most of the capacity requirements - in my home they consume 3.5kW each and 14kWh battery would sustain 1 such HVAC for less than 1.5 hrs if 3 days of autonomy required.

[thirtywest]

greetings all, first post. be patient.

I'm looking over the spec sheet of the tesla powerwall and it's boasting 14 kWh @ 50V. The aH doesn't seem that different than other batteries, but I'm confused on the 14kWh capacity. Is there a conversion between AC and DC amps they are using to claim 14kWh will run a 2-bedroom abode for a x period? I know, I know, it depends on watt hours, but it just seems like an inflated claim until I know the method used.

I'm just getting started--looking at a way to combine a small 2-axis array with a portable gas gen to weather the outages we've had here in Houston during the storms. "burst" generator usage and some simple battery storage to keep two fridges running about 7 hours each day and periodic use of one HVAC (and some random LED kitchen lights).

But, amp conversion--the impetus for the post.

thanks, and I'm researching the archives now too.