Motorhome Inverters

[LEXUS]

Hi
I have a 2013 Bessacar E520.
I would like to fit a suitable inverter to my MH which has a microwave of up to 1270w consumption.
This figure was supplied by Swift who strongly ADVISE AGAINST fitting an inverter to my vehicle presumably because of this consumption.
From the very little I know of the use and application of invertin M/H’s I believe the best model for my application would be a CONTINUOUS SINE invertor of a capacity in the region of 3000w to 5000w.

As I am an OAP of 73 years with very little knowledge of this subject can I ask that any M/H Fun Member who has an inverter of this
range size who is looking to sell the item please reply to this post with an indication of price and postage to central Scotland.

Thanks in anticipation of any help in the acquisition of this item.

LEXUS

 

[34127]

Hi, you might want to change the thread title.

 

[Geo]

Yes I thought he was trying to raise the cash to buy a Motor Home
Bloody spool chucker pain in the arris

 

[Jimbohorlicks]

It may be a cheaper option to change the microwave for a smaller wattage one. We have a 800w microwave, it's a Daewo. But have also installed one in a previous van that was 700w,ex tesco microwave.
We have a 1000w inverter with 290 ah of batteries. But would only run the microwave for about 4 to 5 mins, max, before mid day as it does use up a lot of battery power.
It's great for when on ehu, but not really suitable for inverter use.
Best of luck.

 

[funflair]

Hi LEXUS

Whenever the question of inverters comes up the answer if never about the inverter but about what battery bank and then means of recharging you have, you need to understand what the inverter is taking out of your batteries and how you will put that back, or which drawer the candles are in for when the lights go out.

A pure sine wave 3kw would cover all eventualities.

Martin

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[Richard n Ann]

Hi
I have a 2013 Bessacar E520.
I would like to fit a suitable inverter to my MH which has a microwave of up to 1270w consumption.
This figure was supplied by Swift who strongly ADVISE AGAINST fitting an inverter to my vehicle presumably because of this consumption.
From the very little I know of the use and application of invertin M/H’s I believe the best model for my application would be a CONTINUOUS SINE invertor of a capacity in the region of 3000w to 5000w.

As I am an OAP of 73 years with very little knowledge of this subject can I ask that any M/H Fun Member who has an inverter of this
range size who is looking to sell the item please reply to this post with an indication of price and postage to central Scotland.

Thanks in anticipation of any help in the acquisition of this item.

LEXUS

How many batteries have you got? The microwave will use 106 amps

 

[tonka]

There are many videos on YouTube that explain about inverters. Types, how to install, power consumption etc.
Really worth a watch to understand a little more.

 

[Gaston aires]

Why on earth do you have to use a microwave oven when you are not connected to EHU ? The eat up battery power.
Phil

 

[funflair]

Why on earth do you have to use a microwave oven when you are not connected to EHU ? The eat up battery power.
Phil

Nobody "has to" but some of us "want to" and the coffee machine and the hair dryer and the air-con so you spec the van accordingly

Martin

 

[Gaston aires]

Nobody "has to" but some of us "want to" and the coffee machine and the hair dryer and the air-con so you spec the van accordingly

Martin

I guess so, I didn’t know you could use air con through an inverter. Ok for those who have flairs and morellos, I remember those days.
Regards Phil

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[funflair]

I guess so, I didn’t know you could use air con through an inverter. Ok for those who have flairs and morellos, I remember those days.
Regards Phil

You can run anything as long as you have the batteries to power it and the solar and the means to recharge we can run a lot more in the MORELO than we could in the Flair as we have 320ah LiFePO4 and 520w of solar

Martin

 

[tacr2man]

The only prob with running aircon when not on EHU or with gennie is the amount of solar you need and size of battery bank means a big vehicle which needs more aircon to cool , and round it goes

 

[autorouter]

In principle an inverter is a great idea. The problem is the numbers.

A typical leisure battery is 100Ah (amp-hours). It's 12V, so that means it contains 12 x 100 = 1200 watt-hours of energy. Since it's recommended not to discharge below the 50% level, you've got 600 watt-hours of usable energy.

A 1200W microwave running for 6 minutes (1/10 of an hour) will use 1200/10 = 120 watt-hours. So in terms of energy, that's fine.

The other consideration is the amps. Taking 1200W from an inverter means the 12V battery has to supply 1200/12 = 100 amps. Depending on the battery type, the recommended maximum amps about a fifth of the capacity in amp-hours - for a 100Ah battery that's 100/5 = 20 amps.

To supply 100 amps, you'd ideally need 5 batteries in parallel, each giving 20 amps. OK, for short bursts you could get away with three batteries, or even two if you're pushing it. But a single battery won't cope with 100A.

So, as funflair said, it's more about the batteries than the inverter.

 

[Reallyretired]

Inverter of 3000w continous and 6000w max, pure sine save will see you right. Loads on ebay, I have been using cheap chinese ones for years no problem. You will need more than one battery and adequate solar and/or B2B to recharge, and only use the microwave for a few minutes.

 

[funflair]

The only prob with running aircon when not on EHU or with gennie is the amount of solar you need and size of battery bank means a big vehicle which needs more aircon to cool , and round it goes

I am surprised how little power the air-con takes actually and LiFePO4 batteries are a game changer in terms of power to weight, our roof is nowhere near full with only 4 panels and if we doubled that it would run the air-con with power to spare as it only takes 60-70 amps intermittently when the compressor kicks in.

Martin

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[Reallyretired]

If like me you use starter batteries rather than leisure ones, the high current for short periods is less of a problem.
I use starter batteries because they suit my use better, high current for short period and rapidly recharged from solar. They are also generally cheaper.

 

[7 Bertha]

How is it that I understand household electrics so well, but not motorhome?
We’ve just purchased our first motorhome. Not a grand one, mind and certainly not new, (Weinsberg Meteor 790, 2006 with 22000 miles).
It has two leisure batteries and 3 x 100w solar panels. It has a small inverter connected, sufficient to power and charge a computer and I actually thought of installing a 3000w inverter to increase our options for higher rated items.
One of the batteries is flat and not charging, so I thought, whilst replacing the duff one, I would replace both with large Ah capacity batteries doubling the Ah as a bank for the inverter.
I thought that it would be simple to just swap them over, but it seems there is a “procedure” to disconnecting and reconnecting when reconnecting leisure batteries where solar panels are connected.
I am an absolute newbie to all of this and any help or advice would be much appreciated on how I can do this safely...

Many thanks in anticipation

 

[Jev88]

There is a company that down watts microwaves to order.
Or get one from Amazon.

Amazon product ASIN B00EO2MBUC

 

[7 Bertha]

There is a company that down watts microwaves to order.
Or get one from Amazon.

Amazon product ASIN B00EO2MBUC

Thanks for your reply, but the question was not about microwaves ovens... I’ve never owned one and don’t intend to ever purchase one...Even at home!! It’s about installing a higher power inverter and replacing batteries

 

[funflair]

How is it that I understand household electrics so well, but not motorhome?
We’ve just purchased our first motorhome. Not a grand one, mind and certainly not new, (Weinsberg Meteor 790, 2006 with 22000 miles).
It has two leisure batteries and 3 x 100w solar panels. It has a small inverter connected, sufficient to power and charge a computer and I actually thought of installing a 3000w inverter to increase our options for higher rated items.
One of the batteries is flat and not charging, so I thought, whilst replacing the duff one, I would replace both with large Ah capacity batteries doubling the Ah as a bank for the inverter.
I thought that it would be simple to just swap them over, but it seems there is a “procedure” to disconnecting and reconnecting when reconnecting leisure batteries where solar panels are connected.
I am an absolute newbie to all of this and any help or advice would be much appreciated on how I can do this safely...

Many thanks in anticipation

I think you are referring to the fact that when you connect solar you should connect the controller to the battery and then connect the panel to the controller, the primary reason for this I believe is that the controller needs to see the battery voltage first as some controllers will switch automatically between 12v and 24v depending on what they see when connected.

Martin

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[Richard n Ann]

Just disconnect the solar panel from the solar controller first, then do all the swapping of batteries, then last job reconnect the solar panel to controller

 

[7 Bertha]

Just disconnect the solar panel from the solar controller first, then do all the swapping of batteries, then last job reconnect the solar panel to controller

Excellent... Thank you

 

[Lenny HB]

A 1270 watt microwave will need at least a 2500 watt inverter because of the high start up current and as said a decent battery bank of around 800 a/h if you want your batteries to last. If you have one battery at the moment that would be 8 batteries.

 

[mitzimad]

How is it that I understand household electrics so well, but not motorhome?
We’ve just purchased our first motorhome. Not a grand one, mind and certainly not new, (Weinsberg Meteor 790, 2006 with 22000 miles).
It has two leisure batteries and 3 x 100w solar panels. It has a small inverter connected, sufficient to power and charge a computer and I actually thought of installing a 3000w inverter to increase our options for higher rated items.
One of the batteries is flat and not charging, so I thought, whilst replacing the duff one, I would replace both with large Ah capacity batteries doubling the Ah as a bank for the inverter.
I thought that it would be simple to just swap them over, but it seems there is a “procedure” to disconnecting and reconnecting when reconnecting leisure batteries where solar panels are connected.
I am an absolute newbie to all of this and any help or advice would be much appreciated on how I can do this safely...

Many thanks in anticipation

Batteries Before is how i remember which order the controller has to see the batteries first to register the voltage to charge at

 

[peterc10]

Thanks for your reply, but the question was not about microwaves ovens... I’ve never owned one and don’t intend to ever purchase one...Even at home!! It’s about installing a higher power inverter and replacing batteries

The answer was to the question the original poster asked, not yours.

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[7 Bertha]

Ok

 

[gus-lopez]

Excellent... Thank you

Just remember to safely isolate the wires when off as they will still be live. Usually before disconnecting solar panels I blank them off with cardboard taped down & then also securely isolate their wires.

 

[autorouter]

How is it that I understand household electrics so well, but not motorhome?
We’ve just purchased our first motorhome. Not a grand one, mind and certainly not new, (Weinsberg Meteor 790, 2006 with 22000 miles).
It has two leisure batteries and 3 x 100w solar panels. It has a small inverter connected, sufficient to power and charge a computer and I actually thought of installing a 3000w inverter to increase our options for higher rated items.

The huge difference between 12V and 240V systems is hard to take in at first.
12 volts means each amp carries 12 watts.
240 volts means each amp carries 240 watts.

So 3000 watts requires 3000/240 = 12.5 amps at 240V.
But 3000 watts requires 3000/12 = 250 amps at 12V.

The wire thickness is determined by the amps, not the volts. 250 amps is a serious current, requiring wires as thick as garden hose.

Batteries normally can supply in amps about a fifth of their rated amp-hour capacity. For example, a 100Ah battery can supply 100/5 = 20 amps without undue stress. If you want 250 amps, you will need a battery bank of about 250 x 5 = 750Ah, which is about what Lenny HB said.

And that's before the question of how you refill the batteries with that sort of energy.

 

[7 Bertha]

Thankyou so much for that... That is without doubt the clearest and most succinct answer. Even from Motorhome service points, whose explanations were as clear as mud...