Worth it to buy a smaller microwave?

softdown

Full size units require 1300 watts. Bad enough but it also seems to "shock" cold batteries.

I am wondering if a smaller microwave using about 750 watts would be worthwhile. 

Not going to quit microwaving. Unfortunately I am hooked on the convenience. Though I try not to use it for over two minutes unless the sun is effectively charging the battery bank. 

706jim

I've been using a small microwave on solar for several years. It works fine even with modified sine current. Biggest pain is not being able to use a full sized plate in the limited space.

SteveK

Remember to keep in mind the 1100W microwave uses more like 1500W or VA out the inverter too.

I had a 700W microwave in our smaller 30A camper. Every time we used it was a let down. Things took forever to cook compared to our other microwaves so were just spoiled. We found it took the same amount of energy to cook meals but the times were way longer. So much longer we decided not to use it so I took it out. We moved to a single burner induction cooktop there instead.

SumPower

We found that if you use the power setting on a large micro wave and take your time, the food cooks more evenly.

The total power consumption was about the same between a small micro and the larger one that we replaced it with.

For example, cooking rice in a glass bowl with a glass lid. We would set the micro to the power setting of 50%, then cook for 15 minutes. So the micro cyles full power for 10 seconds, then no heating for 10 seconds, so it would have full power for three 10 second periods per minute and three 10 second periods of no heating. Then let the dish sit for 5 minutes as a finishing process (simmering). Rice was always fluffy and perfectly cooked.

Once you get food up to temp. it takes less heating to keep it simmering. 

softdown

Thanks for the input. So far nobody has indicated that a smaller microwave would significantly help the battery bank. 

With all my freezers it becomes difficult to ascertain what exactly caused a significant voltage drop in the battery bank. It fluctuates a lot. 

Graham Parkinson

Just as a side note to all this - Inverter type microwaves such as the Panasonics actually draw less power when on lower power settings instead of turning on and off like conventional microwaves do to modulate power delivery.   This way you can have a larger microwave, still run on lower power draw and fit larger plates in.

SumPower

Thanks for posting Graham, had no idea that there was an inverter microwave on the market. Researched by googling "inverter microwave oven", and they are supposed to use up to 15 to 17% less power.

Cooked for several years in Latin America and the only appliance we had was a microwave, so this makes it quite interesting for replacement microwave ovens.

SteveK

The inverter microwave sounds like a decent solution. Should bring the otherwise ~35% efficient cooker up to 50%. Thanks. Inverter tech saves us a ton of energy in our basement dehumidifier.

JRHill

I didn't know of inverter MWs until this thread.

I just recently replaced our 10 year old microwave as it was obviously degraded it took a minute+ longer to reheat a coffee, etc. than it did years back. We are anally conservative with power draw and when the MW performance deteriorated it drew the same amount of power while running. If the power draw degraded with run time I wouldn't not have been an issue vs run time.

scrubjaysnesttoo

SteveK said:

Remember to keep in mind the 1100W microwave uses more like 1500W or VA out the inverter too.

I had a 700W microwave in our smaller 30A camper. Every time we used it was a let down. Things took forever to cook compared to our other microwaves so were just spoiled. We found it took the same amount of energy to cook meals but the times were way longer. So much longer we decided not to use it so I took it out. We moved to a single burner induction cooktop there instead.

I changed ours to 1100 watt, draws 60 amps on the inverter input while running. 

SteveK

scrubjaysnesttoo said:

SteveK said:

Remember to keep in mind the 1100W microwave uses more like 1500W or VA out the inverter too.

I had a 700W microwave in our smaller 30A camper. Every time we used it was a let down. Things took forever to cook compared to our other microwaves so were just spoiled. We found it took the same amount of energy to cook meals but the times were way longer. So much longer we decided not to use it so I took it out. We moved to a single burner induction cooktop there instead.

I changed ours to 1100 watt, draws 60 amps on the inverter input while running. 

Sounds about right for a 24V system.

softdown

Just seen that eggs do better if cooked at a lower temp. Seems a smaller microwave would have the same effect. Not going to constantly fiddle with my power settings. I keep forgetting the close the skylights until it gets weirdly chilly.