Here is an inverter under consideration
It is about $250 from China. There are some others on eBay and one for over 1k on Amazon.
Product description
HuiKe pure sine wave inverters represent the most technologically advanced,
lightweight, compact and diverse inverters on the market to help ensure the
widest use of applications. For over a decade, the HuiKe ’ Power has
consistently delivered the broadest range of sizes to accommodate virtually
every power requirement. Advantages of a pure sine inverter: -Equipment
runs more efficiently -Motors run cooler -Cleaner power -Ideal for power tool
chargers, laser printers, electric shavers, microwaves, variable speed motors, TV’s, medical equipment.
Intelligent LCD automatically detects faults and provides modification suggestions.
Full Power, True Pure Sine Wave, No electromagnetic Interference
About Description:
inverter input: 12V/24V/48V/60V/72VDC
DC input range: 10V-15V/21V-30V/42V-58V/50V-70V/70V-90V
Inverter output:AC110+/-5%
Output frequency: 60Hz
Ouput waveform: Pure Sine Wave
Continous power: 2500W
PEAK power: 5000W
Inverter Best efficiency: Aprox 92%~97.2%
No Load Current Draw:less than 0.3
Low Voltage Alarm:10+/-0.5V, 20.5+/-1V, 44+/-1V, 55.5+/-1V, 62+/-3V
Low Voltage Shut Down: 9.5+/-0.5V, 19.5+/-1V, 42+/-1V, 55.5+/-1V, 62+/-1V
Over Voltage Shut Down:15.5V+/-0.5V
Thermal shutdown: 60+ degrees
Cooling Ways: Cooling Fan will run when the temperature is over 50 degree
AC output: 2 BS socket
Voltage input meter: yes
Power out put meter: yes
LCD display
Over Thermal :Shut Off Output Automatically
Fuses: Short Circuit
Start:Soft Start
Protection:Overload, Short Circuit, Overtemp, Reverse Polarity, Under/Over Voltage
Machine Size(mm): 390185150MM
Net Weight(kgs): 5.5kg aprox.
I found this online calculator to be useful.
It does not have 72v but you can just use 36v & divide Amps DC by two.
Amperage
I am aiming to create a 20 Amp 110 VAC supply and slightly oversizing the inverter for headroom.
This is about 34 Amps DC (67.47 / 2 = 33.74). Is this unreasonable? Too much? For comparison, what does the motor draw through the controller?
Runtime
This is an example supplying 1,000 watts. How long will it last?
- 1,000 watts equates to 15.35 Amps DC @ 72v (even less amperage at 80v)
- 160ah / 15.35 Amps = 10.42 hours theoretical max runtime
- 10.42 X 0.80 = 8.33 hours assuming a safe 80% depth of discharge
- 1,000 watts for 8 hours, 500 watts for 16 hours, and so on
Please point out any flaws in the math.
I also found another thread about this idea with @Old_Houseboater @LA-GEM4s @Big_Dee @LithiumGods