Looking at the 360 degree view of the 200L on the web site, on the back panel it specifies 2048Wh, 51.2VDC, 40Ah.
But I’ll be using it at 12VDC almost all of the time. So could we just as easily say that the unit is 2048Wh, 12VDC, 170Ah? I’d like to think I spent my money (on this unit & a PV350 all arriving today!) to nearly triple my overall storage from a single 100Ah BattleBorn LiFePO with a 195W Go Power rooftop panel, to a total of 270Ah, rather than try to justify only increasing my storage by 40Ah with such a cash outlay.
And why 51.2V? Who does that? Does this have anything to do with the mostly useless 48V port on the front of this thing that has only one accessory on the planet to connect a D40?
Wh is an unit of energy.
2048 Wh is the nominal energy that the battery can store.
Energy is energy, it doesn’t change. It only gets lower with efficiency and usage cycles over time.
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If you are only going to use the 12V outlet, without considering efficiency, you will still get 2048 Wh of nominal energy.
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51.2 V is the nominal voltage of the internal battery.
40 Ah is the nominal current of the internal battery expressed as the charged current with the time necessary to discharge it.
If you multiply 51.2*40 you get 2048.
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You can play with the values in your head if you keep the energy which must be equal to the nominal.
So you could “easily imagine” to have a 12.8 V and 160 Ah battery since energy will still be 2048 Ah.
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However, since nominal voltage is 51.2 V, to get 12.8 V there is a conversion efficiency to take into account (51.2 > 12.8), which will result in the Wh value out of the battery to be slightly lower in a real-world usage from 100% to 0%.