I want to run a microwave on an inverter

2oldman wrote:
I'm just curious, what takes 10 minutes in a microwave?

A Big TV Dinner. :)

I've been running my microwave using a Renogy 2KW Inverter to heat a small TV Dinner or a cup of coffee. Maybe 6 minutes max.

When I installed the Inverter, using two Battleborn 100 ah batteries, wired with 2/0 awg wires running about 2' to the Inverter, and monitored by a Victron BMV 712, I found the Inverter was drawing 125 amp and after a one minute run it used exactly 2 amp hours as recorded on the monitor.

A 6 minute TV dinner uses about 12 amp hours.

Nice thing about the LiFePo4 batteries is the lack of significant voltage sag as you see with Lead Acid batteries. This setup has served me well for over a year now and I use it a lot. For every night I spend at a full hookup site, I spend 15-20 days boondocking.

You need a 2000w inverter for that job. We do that all the time. You want a good sized battery bank to run that inverter such as four 6s. In a smaller Rv you could use LFP or SiO2 batts so the inverter will not alarm off while it is running the MW, but you still need AH to run the furnace etc that night. Just means recharge more often so keep the Honda handy!

Inverter at 120amps for 10 minutes is 20AH, not too much, but that is not the only AH draw for the 24 hr day of camping

Main thing is gen quiet hours. You can run the things off inverter early in the morning before gen hours let you recharge the batts. Same thing at night--watch movies off inverter, no gen noise, and then recharge with the Honda next day during gen hours.

With a TC you can carry batteries ahead of the wheel wells in the truck and then wire them up with the camper slid in part way so the wires will reach inside. That way you can carry four 6s, eg, two in the truck bed and two in the camper's battery box. Lots of ways around the problem.

Keep the Honda with you!

If you regularly use that kind of power and don’t have a recharging source like a generator or solar, you likely won’t get them recharged while towing. The generator is still the way to go.

ok, there is an "easy peasy" way to run a microwave on a 1000W sine wave inverter. Been doing it for a decade or more. solution: Buy a panasonic true inverter microwave. rather than cycling between 0% and 100% power on reduced settings it runs continously but on lower power. the 50% power level easily runs on our 1000VA inverter, draws about 850W on that power level.

At 50% power level things like heating water, cooking frozen veggies etc. takes about 25-30% longer than 100% power.

Nice thing is we can use the microwave w/o having to go out and start the generator.

Now for the downside. If your battery bank is a PAIR of GC-2's, likely the inverter won't like the voltage drop if the batteries are below about 80% SOC. four GC-2's and your good down to around 50% SOC. Here is where a pair or even one 12V outperforms the GC-2's. The 12V has WAY less internal resistance and hence voltage drop. and a pair of 12V wins even more with the batteries splitting the current.

BFL13 wrote:
You need a 2000w inverter for that job.

2nd a 2000 watt inverter at least 4 GC2 (400+ amp hours) of batteries properly connected HEAVY (00 or bigger) wire and keep it short. Tape the positive and negative wires side by side for as much of the run as you can. a 3rd pair of GC2 will extend run time.

Source on some of this is Xantrex.

zzyzxpat wrote:
if using the microwave for say 10 minutes, do you see a huge battery drain?

Yeah. You'll need at least 4 well-charged GC batteries for that, or lithium.

Ran our Panasonic 850w (cooking watts only) conventional MW from two GC’s and a 2000w ProSine Xantrex (0004 cabling) for over a decade without a single glitch (typically up to a minute or two at a time), but a less demanding inverter MW would now be my choice…Robust cabling prevents excessive voltage sag…

3 tons

I occasionally need to run our microwave from the inverter. It’s a very small unit that pulls about 950 watts total, so it’s slow. I only have one battery, a group 31 AGM. When we’re dry camping, I use a 1000 watt Yamaha generator for most of our power needs. The inverter is a 1500 watt pure sine. The Yamaha by itself can’t run the microwave directly, as it can only sustain about 900 watts.

What I found out by accident though, was if I put the microwave on the inverter while the generator is running, the 45 amp battery charger will kick in and supply about half the wattage, and the battery will supply the rest. Of course the generator kicks into high gear, but it doesn’t overload it. I can run the microwave like that for more than long enough to get a meal nuked. Also, it keeps me from having to turn off the Yamaha, move the shore power cord, then start the built-in generator just to run the microwave about 10 minutes.

The turntable motor in my microwave has been growling though, so instead of trying to find a replacement part for it, I’m going to find an inverter microwave that will fit and give that a try.

:):)

jkwilson wrote:
If you regularly use that kind of power and don’t have a recharging source like a generator or solar, you likely won’t get them recharged while towing. The generator is still the way to go.

Not true if you are using a DC-DC charger !

If it heats, cools or drives something mechanical it is a power hog. To get any meaningful power for any sort of duration you need a large battery bank. To get longevity out of the inverter you don't want to be demanding near 100% capacity out of it for any length of time. For voltage sensitive things, such as microwaves, you will need a pure sine wave inverter or risk the early demise of whatever it is powering.

If all of this is starting to look pricey, it is.