Electric Equipment

[David & Ann]

I have a 1000w Inverter. Is it possible to plug in a Toaster or a Microwave? A guy in Spain told me it is possible, BUT, any electrical goods should not exceed 1/3 of the power of the Inverter. Meaning, Toaster and Microwave should not exceed 300w, if using a 1000w Inverter. I have looked high and low for Toasters and Microwaves with a lower wattage, but no luck to date. Advice would be much appreciated.

 

[Deleted member 775]

i dont think it is advisable also your battery wont last too long i have a 750 watt one but only use it for the tv and free veiw box phone charger and the like . ps i know you can buy 24 volt micro waves some truckers use them but i dont know how good they are

 

[BedfordMJ]

I seem to think the power of a microwave is rated in the cooking power not the power it actually uses - which is more.
I may be wrong though.

 

[Deleted member 775]

if i am not mistaken there was some discussions a while back on microwaves but i think they are not that efficient on power they use quite a lot of power ok they are not on for long but they consume quite a bit while they are on

 

[shortcircuit]

The 1/3 of power baffles me as it is not logical. If it says it will provide 1000w, then that is what it will provide. You get now't for now't and to give you that output it will need greater than 1000w input and possibly this is where the 1/3 is coming from although that is excessive losses.

The rated output of a microwave is normally the heat it will proved. It does loose a lot in conversion and this is more likely to be where the 1/3 is coming from.

I have a 2000w inverter and it will exceed this amount for a short period. I run the microwave and more importantly the hair drier. Use gas for toast unless on hookup

The most important factor in an inverter is the capacity of the batteries. If you do the conversion factor to run a 1000w inverter on full bore will take a lot of amps out of the battery, 80A+, and it needs to be located near the battery with heavy connections, normally welding size cable. I have 2 x 110A batteries.

Hope this helps

 

[David & Ann]

Thank you all for your input and advice. When I say 1/3, I meant, for example: toaster and Microwave are 750 watts. Then the inverter must or should be atleast 2000to 2500 watt. I have 3 x 100AH leisure batteries which are powered with 2 x 120 watt solar panels. Of course, it would be wise to use only one gadget at a time. Would you suggest I exchange my 1000w Inverter for a 2500w Inverter ?. Your thoughts and advice would be appreciated.

 

[shortcircuit]

You have the battery capacity. Are they close together in order that the leads are as short as possible to the inverter.

The choice to uprate the inverter will depend on how you are going to use it. A larger inverter will give you additional capacity. A 1/3 on to 750w will make it 1000w and not the 2000>2500w you indicate. If you allready have the 1000w, then give it a try,

I have a second inverter fitted at 300w. As the 2000w takes about 1 amp on standby this is inefficient. My 300w powers tv, phone charger etc and could probably have been smaller, 150w to reduce the standby current. It is only switched on when needed

 

[robjmckinney]

Maplins are doing cheap microwave ovens that operate 12/240 for about £99!

This would resolve you battery supply issues!

 

[David & Ann]

Maplins are doing cheap microwave ovens that operate 12/240 for about £99!

This would resolve you battery supply issues!

Hi Rob,
Have you by any chance the phone number or e-mail address to Maplins. I live in Cornwall. I have tried to find one in my area, without success

 

[David & Ann]

You have the battery capacity. Are they close together in order that the leads are as short as possible to the inverter.

The choice to uprate the inverter will depend on how you are going to use it. A larger inverter will give you additional capacity. A 1/3 on to 750w will make it 1000w and not the 2000>2500w you indicate. If you allready have the 1000w, then give it a try,

I have a second inverter fitted at 300w. As the 2000w takes about 1 amp on standby this is inefficient. My 300w powers tv, phone charger etc and could probably have been smaller, 150w to reduce the standby current. It is only switched on when needed

Hi Shortcircuit, Perhaps you misunderstood me. For example: If a Microwave has 750 watts, I was given to understand it must be 3 times more powerful. i.e Inverter should be atleast 2250 watts. Meaning 750w is 1/3 of 2250w. I have already tried plugging in a 750w Microwave through my 1000w inverter. The microwave comes on for a few seconds and then cuts out. I take it the power from the Inverter is not enough. Which is why I am seeking advice if I should upgrade to a larger Inverter. I still do thank you for your imput on this subject.

 

[shortcircuit]

Yes you need to uprate if the overload protection is activating.

Maplins oven on 12 volts will still require a heavy supply "Up to 660W power via direct to battery connection and 175W via cigarette lighter socket"

 

[steve4kay]

Maplins

just google maplins electrical stores and up she comes.....your nearest store is in plymouth. plus phone numbers and product details. happy shopping !

 

[David & Ann]

just google maplins electrical stores and up she comes.....your nearest store is in plymouth. plus phone numbers and product details. happy shopping !

Thanks Steve. Why did I not think of that. Old age is catching up, I suppose.

 

[David & Ann]

Yes you need to uprate if the overload protection is activating.

Maplins oven on 12 volts will still require a heavy supply "Up to 660W power via direct to battery connection and 175W via cigarette lighter socket"

Thanks Shortcircuit. I have a 185w built into the dash as standard in my Fiat, Ducato. I think I will go for a 3000w Inverter. Yes, I do have all 3 batteries, 110AH wired up in a row in heavy duty cables. Everyone has been very helpful, thanks, once again.

 

[Deleted member 3011]

Any decent inverter will have several ratings - the most important will be the continuous rating - ie 1000 watts, which means it is capable of supplying 1000w forever (or until the battery dies, which at close to 100 amps draw is not very long - perhaps 15 minutes for a 100Ah battery and then only at the risk of seriously reducing the life of the battery)

Often the better quality units will have a 5 minute (or even 30 minute) rating 50% higher than the continuous rating and it is OK to make use of this rating for short periods PROVIDED the cables and fuses AND battery are able to handle the loads.

Use of a microwave AND a toaster OR kettle at the same time would never be a good idea even if the inverter was big enough because drawing extra-high currents from deep cycle batteries is NEVER a good idea.

Generally accepted good practice is never to draw more than 50% out of a flooded battery and 70% out of an AGM and then only if it can be replaced the same day. These draws are calculated at a current draw of 5% of the Ah rating of the battery and the general rule is the higher the current draw, the lower the Ah the battery will deliver. Treat them properly and they will last for years, hammer them and leave them discharged and you may be buying new batteries every few months

NB -- microwaves are a special case. A 750W (cooking power) microwave will draw more than 1000w from the power supply - which is why your (cheap????) 1000w inverter won't handle it. Look on the ratings label on the back to get the true power requirements.