We never overnight outside of marina.. Wanted something to cool down the cabin for a few hours.
My cabin is small, 6,000btu unit only pulls about 4amp.

Grock designed the whole set up.

I wanted 4 hours of run time

Very cool idea, so simple to install and maintain compared to a genset. Sounds like it meets your needs perfectly.

Is that 4 amps include the electric water pump for cooling? or just the AC unit? if not then you may need to add 1 more amp to that calculation... :)

I was shooting from the hip.

Grock says :

Step 1: Calculate Total Power Consumption

• Air Conditioner: As calculated previously, 5.7 amps at 120V = 5.7×120=684 W 5.7 \times 120 = 684 \, \text{W} 5.7×120=684W.
• Water Pump: 1 amp at 120V = 1×120=120 W 1 \times 120 = 120 \, \text{W} 1×120=120W.
• Total Power: 684 W+120 W=804 W 684 \, \text{W} + 120 \, \text{W} = 804 \, \text{W} 684W+120W=804W.

Step 2: Account for Inverter Efficiency

Assuming 90% inverter efficiency (as before), the power draw from the battery is:
Battery Power Draw (W)=Total AC PowerInverter Efficiency=804 W0.9≈893.33 W\text{Battery Power Draw (W)} = \frac{\text{Total AC Power}}{\text{Inverter Efficiency}} = \frac{804 \, \text{W}}{0.9} \approx 893.33 \, \text{W}Battery Power Draw (W)=Inverter EfficiencyTotal AC Power​=0.9804W​≈893.33W

Step 3: Battery Usable Energy

The Core Mini 12.8V 200Ah LiFePO4 battery has a total energy capacity of:
Energy (Wh)=12.8 V×200 Ah=2560 Wh\text{Energy (Wh)} = 12.8 \, \text{V} \times 200 \, \text{Ah} = 2560 \, \text{Wh}Energy (Wh)=12.8V×200Ah=2560WhAssuming a 90% depth of discharge for safety:
Usable Energy (Wh)=2560 Wh×0.9=2304 Wh\text{Usable Energy (Wh)} = 2560 \, \text{Wh} \times 0.9 = 2304 \, \text{Wh}Usable Energy (Wh)=2560Wh×0.9=2304Wh

Step 4: Calculate Runtime

Runtime is calculated as:
Runtime (hours)=Usable Energy (Wh)Battery Power Draw (W)=2304 Wh893.33 W≈2.58 hours\text{Runtime (hours)} = \frac{\text{Usable Energy (Wh)}}{\text{Battery Power Draw (W)}} = \frac{2304 \, \text{Wh}}{893.33 \, \text{W}} \approx 2.58 \, \text{hours}Runtime (hours)=Battery Power Draw (W)Usable Energy (Wh)​=893.33W2304Wh​≈2.58hours

Step 5: Real-World Considerations

• Startup Surge: The air conditioner’s compressor surge (potentially 1368–2052W) plus the pump’s steady 120W is still within the inverter’s 2000W continuous and ~4000W surge capacity, so it should handle both loads.
• Duty Cycle: If the air conditioner cycles (e.g., 50–70% on-time), runtime could extend. Assuming a 60% duty cycle for the AC (684W × 0.6 = 410.4W) plus the pump’s 120W (total 530.4W AC, or ~590W from the battery), runtime could increase to:

Runtime (hours)=2304 Wh590 W≈3.9 hours\text{Runtime (hours)} = \frac{2304 \, \text{Wh}}{590 \, \text{W}} \approx 3.9 \, \text{hours}Runtime (hours)=590W2304Wh​≈3.9hours

• Other Factors: Battery age, temperature, and partial charge could reduce capacity. The pump is assumed to run continuously; if it cycles, runtime could improve slightly.

Final Answer

With the Marinair 6,000 BTU air conditioner (5.7 amps at 120V) and a water pump (1 amp at 120V) running continuously, the Core Mini 12.8V 200Ah LiFePO4 battery will last approximately 2.6 hours through the Dakota Lithium 2000W inverter. If the air conditioner cycles at a 60% duty cycle, runtime could extend to about 3.9 hours. To extend runtime, consider energy-saving modes, reducing pump usage, or adding solar charging.

If I need more than that I can add an extra battery ..

AI also designed my seats .
I executed the design.
Came out great.

https://cimg9.ibsrv.net/gimg/www.off...a86f1cdb3a.png
https://cimg8.ibsrv.net/gimg/www.off...45e5a1f8f0.jpg

Parts come in? Dyno day? Good news? Big numbers?

First engine made 1050hp at 6200 with 7ish psi.
1075 with another pound of boost but I like the my boost to be on the low side side so I`m good with 7psi, lets just go boating . Boat doesnt need a bunch of power to go fast.

Eddie has reluctor rings lazer cut for the most accuracy. For some reason this time around the guy sent him reluctor rings made from stainless. I think he was thinking he was helping him out but he fu%$ed him instead lol.
That was a difficult diagnosis to figure out .
No crank signal.. well you need a metal wheel for the crank sensor to see it so that took a bit to figure out.

Reluctor wheels should be in by now second engine dyno tomorrow.

That's great news man congrats! Almost there!

very nice..........:ernaehrung004:

Thanx Guys.
That HP # is with my headers and all accessories.
Throw on dyno headers and strip off accessories 1100hp plus easy.


Fast enough for me: