how many watts for how long

[Upfisk]

Donna,

When we are boondocking, and it is the winter months, and we are running the furnace i would use the Instant Pot to fix dinner...if it is forecast to be sunny tomorrow. It is all situational. If it is July and forecast to be cloudy tomorrow, and we are boondocking, I would use the Instant Pot. We do monitor our battery state daily, and make inverter usage decisions based on that. We spent 18 years on a sailboat with most of our charging from solar and wind, and know what voltage means for our usage.

[Donna D.]

Thanks. I've only truly boondocked less than 10 days, in Ten Foward. And that was in the heat/bright sunlight of the summer. I do have the 170w solar and dual 6v batteries... I just don't like to be cold! Your information helps, truly.

[StillCampin]

I use my 3 qt IP when boondocking to make yogurt all the time. But, the Honda provides the basic power. When the heating element is on I see about 8-9 amp (total) draw that occurs for about the first few minutes and then seems to cycle for about 10-15 seconds every few minutes. I used a Kill-a-Watt meter once and the total was surprisingly low. Unfortunately I'm currently boondocking in the AZ desert and my notes are at home. For yogurt, which needs many hours of maintaining the temp, once it gets to temp I unplug and wrap the whole pot & put it outside in the sun for the day. Made my 3rd batch in 2 weeks just a couple days ago.

[MyronL]

How about if using a sewing machine? Dear One wants to bring one with her and use it to pass time at Quartzsite. We have 200 watts of solar, and a 600 watt inverter, dual 6v batteries. I told her, "no problem," but what do I know?

[Oldtimer]

Get her a pedal sewing machine

[Upfisk]

Myron,
I sewed on our sailboat using a 300 watt inverter. Always had enough power with a 1/8 HP motor on the sewing machine. It was an industrial Bernina from the 1930's and could sew sail cloth. A domestic home machine should draw the same or less.

[peter]

Originally Posted by MyronL

How about if using a sewing machine? Dear One wants to bring one with her and use it to pass time at Quartzsite. We have 200 watts of solar, and a 600 watt inverter, dual 6v batteries. I told her, "no problem," but what do I know?

My wife always brings her sewing machine and pieces quilts everywhere using solar. Our solar panel installed on our 2013 19 has no problem running her small Jenome or Singer Feather Lite machine.

[MyronL]

Thanks, guys. I knew it!

[Ron in BC]

Originally Posted by Upfisk

We spent 18 years on a sailboat with most of our charging from solar and wind, and know what voltage means for our usage.

Us too and years before battery monitors came into common use. Heck, I even had an analog voltmeter at one point. But yes, using battery power day after day and watching the voltmeter does give you a pretty good idea of your situation.

Ron

[lynne r]

Upfisk
We have an older, 2011 19 ft and just went back to the factory last summer for a 170 watt solar panel and a 1500 watt Go Power inverter. I am an Instant Pot believer and wanted the inverter for my baby 700 watt pot. I have tried to use it twice and the inverter makes a noise...the fan I guess....and it appears to shut off multiple times while attempting to pressurize. Both times the pot did obtain pressure and cooked but I worry that something is not working right. I did watch the voltage drop to 12.3 but it came right back up immediately when it cut off and after it pressurized (I was prepared to unplug if it went below 12.2.)
We have camped for years without an inverter....I just wanted it for the IP. Am I killing my inverter?

[Upfisk]

Lynne, our IP does the same with the inverter. The only time it is semi constant is when building pressure, that seems to be 10 minutes or so. After that point it is up and down with watts consumed or not. It is totally normal. Every time we used the IP our meals cooked successfully.

We picked up our 19 on Oct 1st, 2018. The inverter had a loud fan that would come on, and a buzz when we plugged into it. After 4 weeks the inverter died. Go Power sent us a new inverter under warranty.

The new inverter is mostly silent, when the IP is drawing 700 watts the fan does come on, the buzzing is gone. Our original inverter was faulty from the beginning, the IP did not kill it. Another appliance we use is a small wired vacuum cleaner, the watts drawn go up and down depending if a floor rug is being cleaned or pet hair removed from a cushion. The inverter is meant to handle varying loads.

[padlin]

Hi Lynne & David, can you post the make and model of the pot? 700 watts is usually the output as opposed to the input it pulls from the inverter, which is probably up around 1000 watts, add in 10% or so for inverter loss, or about 1100 watts. Still it should not be an issue as your inverter is 1500w. Have you tried the pot when you have city power to verify the pot is okay? Is anything else running on the inverter when using the pot?

Don't know which inverter you have, but the 2 current 1500 watt models of GoPower work from 10-16 vdc so the 12.2 or 3 you see should be fine.

[Brian B-P]

Originally Posted by padlin

Hi Lynne & David, can you post the make and model of the pot? 700 watts is usually the output as opposed to the input it pulls from the inverter, which is probably up around 1000 watts, add in 10% or so for inverter loss, or about 1100 watts

The instant Pot just uses a resistance heater, so the heat output of the device is essentially equal to the electrical power input to it from the inverter (less a few watts to run the electronic controls). If it is identified as a 700 watt model (any of Instant Pot's "Mini" pressure cooker models), that's the heater power and it is both the power input and the heat output.

This is very different from a microwave oven, which is not a resistance heater and would take about 1000 watts of electrical input (as shown on the electrical info sticker on the appliance) to produce 700 watts of microwave energy output (as indicated by the nominal rating of the appliance).

[Brian B-P]

Originally Posted by lynne r

We have an older, 2011 19 ft and just went back to the factory last summer for a 170 watt solar panel and a 1500 watt Go Power inverter. I am an Instant Pot believer and wanted the inverter for my baby 700 watt pot. I have tried to use it twice and the inverter makes a noise...the fan I guess....and it appears to shut off multiple times while attempting to pressurize. Both times the pot did obtain pressure and cooked but I worry that something is not working right. I did watch the voltage drop to 12.3 but it came right back up immediately when it cut off and after it pressurized (I was prepared to unplug if it went below 12.2.)

Where was that voltage measured? The voltage at the input terminals to the inverter could be significantly lower than at the battery, due to resistance in the wires between the battery and inverter.

[Upfisk]

Hi Brian, if Lynne measure her volts the same place I measured mine it is at the face of the battery monitor, inverter control, charge controller, under the drivers side dinette seat. It fluctuates all the time based on clouds rolling by, fans turning on, or the IP changing wattage.

[Vermilye]

Originally Posted by Brian B-P

Where was that voltage measured? The voltage at the input terminals to the inverter could be significantly lower than at the battery, due to resistance in the wires between the battery and inverter.

Which, because Escape uses minimal sized wiring for the inverter, can be improved with larger wire. If you are going to hit your 1500w inverter with a full load, I'd suggest following the recommendations of Xantrex (another inverter manufacturer), and going to at least #0 wire for a 1500 watt inverter. This may prevent the inverter from alarming or shutting down due to low voltage.

Again, if you batteries are already down, or getting a bit long in the tooth, it may not help, but if there is a significant difference between the battery voltage & the voltage at the input of the inverter at full load, larger wire will help.

If you have solar, starting the Instant Pot while there is full sun on the panel will help. Even if your batteries are fully charged & the solar controller is in the float mode, the additional load of the Instant Pot will switch it to the bulk or absorption mode, providing a bit more amps from the panel & less from the batteries.

[Brian B-P]

Originally Posted by Upfisk

Hi Brian, if Lynne measure her volts the same place I measured mine it is at the face of the battery monitor, inverter control, charge controller, under the drivers side dinette seat.

That's essentially the voltage at the battery end of the wires between the battery and inverter, so while the inverter is using high current the voltage at the inverter could be significantly lower... and that can be improved, as Jon explained.

[lynne r]

We have the 700 watt Duo Mini 3 Quart IP.
The few times I tried to use it while boondocking it was mid afternoon, nothing else was using the battery and the battery read 100 %. I am reading this voltage like Upfisk said on the face of the Go Power solar controller on the side of the bench. I also had the door open to promote air flow.
So I may try it again but suspect that it is the wire size......which was the deduction of some other fiberglass friends who have electrical experience.
Thank you to everyone who responded!

We will be at Dome Rock by Monday at the latest and would love to meet anyone who cares to look us up. Big Blue Tundra, red graphics on the Escape. And thanks, Jon. Hope to see you again!

[Upfisk]

Frankly, if the inverter is a 1500 watt inverter and the instant pot is using 700 watts, it is absolutely no where near it's maximum load, kinda like half instead. So why should the wire size be upgraded? The biggest load we will ever run is 1000 watts on a tea kettle with the same heater type element as the instant pot. That kinda seems like 66% of the load which is giving the wires to the inverter some extra capacity. Nope, we are not changing wires from the batteries nor to the inverter. Our load selection is taking care of the wire capacity being slightly undersized for the full 1500 watts.

We have NOT had the inverter alarm ever from overload nor have we had it shutdown due to overload. We did have a manufacturing defect in our inverter, but it was not from overload.

[Brian B-P]

Originally Posted by Upfisk

Frankly, if the inverter is a 1500 watt inverter and the instant pot is using 700 watts, it is absolutely no where near it's maximum load, kinda like half instead. So why should the wire size be upgraded?

Because according to this, the current used at 700 watts is enough to drop the input voltage to the inverter too low for operation (to 10.3 volts or lower), despite 12.3 volts (or more) at the battery:

Originally Posted by lynne r

I have tried to use it twice and the inverter makes a noise...the fan I guess....and it appears to shut off multiple times while attempting to pressurize.
...
I did watch the voltage drop to 12.3 ...

It's either too much voltage drop in inadequate wires, or too much voltage drop due to poor connections to those wires (possibly just a loose screw), or a defective inverter (unlikely), or some combination of these factors.

The manual for the GP-HS1500 says

Please use 10 ft or less of #2 Cable with a 200 Amp fuse.

At 200 amps, 10 feet (each way, so 20 feet round-trip) of 2 ga copper wire (0.16 mohms/ft) will drop 0.63 volts; that would avoid low-voltage alarms as long as the battery stays above 11.33 volts.

Are the wires which Escape used to connect the inverter to the battery less than ten feet long, and 2 gauge? Are they the resistance equivalent (e.g. less than 5 feet of 6 gauge, or 2.5 feet of 8 gauge)? We're not talking about an upgrade from what GoPower calls for, but an upgrade from what Escape installed.

At only 700 watts, 11 volts to the inverter, and 90% inverter efficiency the current would only be about 70 amps; the Escape's cables are also presumably less than 10 feet long. Unfortunately, I don't think they're anywhere near 2 gauge conductors.