Buying an Inverter tomorrow. Tips please

[davidathomas42]

So as I am full timing in the Motorhome these days but with just a 125ah leisure battery and no solar yet. Next month hopefully.

I need to get an inverter for saving money parking off grid away from Caravan & Motorhome club sites when I need a proper whack of power to recharge the laptop etc.

I drive the van daily so the battery remains fully charged. But Solar will be going in soon so I can do more with 240v inverters and maybe stay places 2/3 days without power worries.

My plan is to wire it myself in the garage (direct to the battery) which is fully accessible from the inside of the van and then if needed I can just leave stuff in there charging or potentially run a short extension cable to the lounge area and put away again later.

I have just taken a quick look at Towsure in Sheffield as that's where I generally shop for stuff as its a few miles from me 90% of the time.

I am happy to go other places locally but prefer this time to not shop online as Id like to get it fitted this weekend and mail is obviously a hassle now living in the van.

This is what they offer.

Stuff ill be charging. For now

Laptop (MacBook)
Phone portable charging brick USB type
eBike with 500wh battery (not charging it daily. Maybe once a week)
Electric skateboard with 200wh battery (same charge amount as bike)
Magic Bullet Blender
Kettle for conveyance only (dogs food so twice a day for a small amount of water)(I don't drink tea or coffee ever)
Thats about it really apart from maybe the odd extra that creeps in like charging my electric drill etc.

Anyway. Would any of those about work for me from peoples experience. Or can you point me at more suitable ones.

Thanks.

 

[TheBig1]

forget the inverter until you have solar and another battery. avoid the towsure ones, not great

 

[pappajohn]

Personally I wouldn't plug a laptop in any of those.
They are, looking at the prices, quasi sinewave inverters, a laptop or any electronic gadget needs a pure sinewave inverter.
Triple or even quadruple those prices for a cheap one.
One battery is insufficent even with a solar panel, you can't guarantee sunshine.
Two or three batteries would be better but then they need a reliable means of being recharged.

Kettle...... Gas.
Far more cost effective and efficient than electric.
Phone. ... Cig lighter USB adaptor
Why convert 12v to 230v to convert it back to 5v for the phone charger... 12v to 5v is more efficient.
You can buy 12v to 19v converters for laptops

The only things you're really stuck with are the bike, board and blender.

 

[gus-lopez]

Buy a charger for the van to charge the lap top when driving.

 

[DBK]

You would need a 3,000W inverter for a typical domestic kettle. Your other uses need less power so I suggest a cheap whistling kettle from somewhere like Go Outdoors or anywhere like that.

The eBike uses the next most power and I would suggest a 1,000W pure sign inverter and only charge the bike when you are driving. You might get away with a smaller one but it could be working near its peak at times.

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[Two on Tour]

In order of priority I would go for :-

More good batteries
As much solar as you can get on the roof
A good B2B charger then you can belt the amps into the batteries by running the engine
and then think about a good quality pure sine wave inverter like a Sterling.

 

[davidathomas42]

That shot down my plans tomorrow then lol.
I have a 2nd identical leisure battery so I could do a build to link them and make it 250ah over the two fairly easily.

Guess it’s solar first though and rob power where I can.

I have seen the 12v MacBook chargers so that covers that.

The bike I guess I can charge at the gym and work as the battery is removable.

The board i could also charge at work as I use that from the start car park to the crew room so really just need to plan my charge days.

Phones yea easy enough from the cig sockets of which the van has 3

I have a gas kettle already.


It’s just my blender. That’s for my breakfast protein shake so need that daily.

A cheap inverter could work that for now though right until I get fully up to spec on the rest?

 

[DBK]

That shot down my plans tomorrow then lol.
I have a 2nd identical leisure battery so I could do a build to link them and make it 250ah over the two fairly easily.

Guess it’s solar first though and rob power where I can.

I have seen the 12v MacBook chargers so that covers that.

The bike I guess I can charge at the gym and work as the battery is removable.

The board i could also charge at work as I use that from the start car park to the crew room so really just need to plan my charge days.

Phones yea easy enough from the cig sockets of which the van has 3

I have a gas kettle already.


It’s just my blender. That’s for my breakfast protein shake so need that daily.

A cheap inverter could work that for now though right until I get fully up to spec on the rest?

Just looked up Magic Bullet blenders and the one I found was 900W which would suggest something like a 1500W inverter to be on the safe side. I fitted a pure sign one of this rating costing around £150 though the cables and accessories will add at least another £50 to this. Assuming you only run it for a short burst (30 secs max ?) a single battery should be enough though two would be better.

 

[pappajohn]

It's the bike charger that's the killer.
Assuming the chargers input wattage is 120watts then via an inverter it's 10amps per hour from your battery
Assuming it takes 5 hours to recharge that's your single battery almost technically flat (45% discharged) without using anything else.
It shouldn't be discharged below 50%.
Then of course, it needs to be recharged before you can use it again.

 

[pappajohn]

something like a 1500W inverter to be on the safe side. I fitted a pure sign one of this rating costing around £150

I bet if it was put on an oscilloscope that 'pure' wave would look like a ripsaw blade.
I would expect £600/£700 minimum for a quality 1500w pure sinewave.

Unknown Chinese brand?

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[davidathomas42]

Just looked up Magic Bullet blenders and the one I found was 900W which would suggest something like a 1500W inverter to be on the safe side. I fitted a pure sign one of this rating costing around £150 though the cables and accessories will add at least another £50 to this. Assuming you only run it for a short burst (30 secs max ?) a single battery should be enough though two would be better.

Just checked mine as it’s the Nutra Bullet one and it’s 1000w

I run it for 12 seconds.

 

[pappajohn]

Just checked mine as it’s the Nutra Bullet one and it’s 1000w

I run it for 12 seconds.

You wouldn't even notice the power used with that.
It's about 9amps per Hour. I can't calculate that to 12 seconds without a calculator.
The inverters internal losses would be higher than that's power consumption.

Did I mention inverters use battery power even when not in use.
They must be disconnected, not just turned off, when not in use.
The on/off button only turns off the 230v output, not the input.

 

[hilldweller]

Laptop (MacBook)
Phone portable charging brick USB type
eBike with 500wh battery (not charging it daily. Maybe once a week)
Electric skateboard with 200wh battery (same charge amount as bike)
Magic Bullet Blender
Kettle for conveyance only (dogs food so twice a day for a small amount of water)(I don't drink tea or coffee ever)
Thats about it really apart from maybe the odd extra that creeps in like charging my electric drill etc.

Anyway. Would any of those about work for me from peoples experience. Or can you point me at more suitable ones.

Thanks.

I have a 300W pure sine wave inverter that will do all the above except the kettle. Heating foods by inverter is not a good idea, gas is so much better.

 

[Lenny HB]

I bet if it was put on an oscilloscope that 'pure' wave would look like a ripsaw blade.
I would expect £600/£700 minimum for a quality 1500w pure sinewave.

Unknown Chinese brand?

Not put a scope on my cheap one (scope is buried in the loft) but it ain't that pure if I plug the laptop supply into it the mouse pad jitters all over the place but fine with a usb mouse also the the boss's crappad throws wobbles. Better than a modified sine but it it's not that good but a least it doesn't blow anything up. Only really use it for the bikes keep thinking about replacing it with a decent one.

 

[davidathomas42]

Don't judge me!

I don't have time yet to go get a pure sine wave inverter. And yea the cost for a decent one is far more than I thought.

Really Gas low and Solar are my first fish to fry. And increasing the battery bank

Below is a picture of my 2nd leisure battery. It's the exact same and same age as the other one fitted with only slightly less use time.

Next days off I plan to link it to the other one in the space in the 2nd picture in the garage which is accessible from the cab area. (just need to work out boxing and venting)

As a tempory measure I bought this modified sine wave inverter today. I have tested it running my blender and charging my laptop and it worked ok. I plan to check the voltage drop of the battery tomorrow as it was bang on 12.5V before connecting and 12.48 once connected with no load.

Yes am I sure its crap and no I won't risk charging big stuff like the eBike etc. but to just run my blender or throw some juice in the laptop every now and then it should work until I get the other box's ticked and find a proper inverter.

I plan to link it to the batteries with a separable plug or switched so it's completely isolated when not in use.

Anyway.. It was £90 and solves a couple of issues off grid for me at the moment.

Next fish to fry will have to me the gas low as I just switched to my 2nd 6kg calor bottle at a cost of £28 and they last me about 10 days with heating and cooking at the moment. Thats far too expensive. Im on grid 50% of the time at the moment so works out circa £3 a day for my heating and cooking. Thats about as much as living in bricks and mortar

Anyway that was my day.

Off to bed in an hour as up at 7am to go fly a very large plane to Turkey. Already at work which is good so just a short stroll to the office in the morning

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[possar]

if you want to charge the laptop you can buy a 12volt charger up to 24 volt model number l40bb 120 watt,i bought mine at the chinese shop in spain but have seen them on ebay.
possar

 

[possar]

L40BB 120 WATT

 

[mfw]

I've got a bestek 2000 w inverter looks similar to yours but mine has 2 pos and 2 neg terminals + 2 pos and 2 neg leads - when i connected using single cable as yours is connected cable got very hot - but using both leads cable was warm - might be worth checking your cable to battery is not getting too hot

 

[Bart]

Personally I wouldn't plug a laptop in any of those.
They are, looking at the prices, quasi sinewave inverters, a laptop or any electronic gadget needs a pure sinewave inverter.
Triple or even quadruple those prices for a cheap one.
One battery is insufficent even with a solar panel, you can't guarantee sunshine.
Two or three batteries would be better but then they need a reliable means of being recharged.

Kettle...... Gas.
Far more cost effective and efficient than electric.
Phone. ... Cig lighter USB adaptor
Why convert 12v to 230v to convert it back to 5v for the phone charger... 12v to 5v is more efficient.
You can buy 12v to 19v converters for laptops

The only things you're really stuck with are the bike, board and blender.

Very true indeed , the only thing we use our inverter for is to power the microwave , which TBH you can adjust and do without , 12V is king

 

[tonyidle]

I'm rather at a loss to understand why any modern electronic device would be affected (in any way that would cause damage) by a modified sinewave inverter. Earlier devices used a transformer in the power supply that won't work with a modified sinewave device and rechargeable toothbrushes still do but pretty well anything else is powered by a switched mode power supply. A switched mode PSU output is chopped DC followed by whatever smoothing can be crammed into the wall wart or other small plastic box. At the other end the input to the PSU is rectified and stored in a large (-ish) capacitor. What exactly is the likely effect of using a modified sinewave inverter on, say, a laptop? I should say I've seen no effect on anything (other than a toothbrush).

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[autorouter]

I'm rather at a loss to understand why any modern electronic device would be affected (in any way that would cause damage) by a modified sinewave inverter. Earlier devices used a transformer in the power supply that won't work with a modified sinewave device and rechargeable toothbrushes still do but pretty well anything else is powered by a switched mode power supply. A switched mode PSU output is chopped DC followed by whatever smoothing can be crammed into the wall wart or other small plastic box. At the other end the input to the PSU is rectified and stored in a large (-ish) capacitor. What exactly is the likely effect of using a modified sinewave inverter on, say, a laptop? I should say I've seen no effect on anything (other than a toothbrush).

Some devices with power controllers use phase control. As the voltage rises along a smooth curve, the controller shuts off the power when it reaches a pre-set trigger point. So it can switch off for 1/3 of the time to reduce the power from 100% to 67%, for example. That's an oversimplification, but the point is, the controller is expecting a smooth voltage curve and its control algorithm is based on that.

Complex modern devices like an automatic coffee machine or microwave may have a phase controller, for the heater element for example. Certainly LED dimmers have them - you have to be careful to use the correct type - 'leading edge' or 'trailing edge' phase controllers as required by the LED lamp circuit.

As for damage, maybe there's not much risk. But my microwave heats much slower when on a 2kW Modified Sine Wave inverter, and my automatic Nespresso machine won't even start.

 

[tonyidle]

As for damage, maybe there's not much risk. But my microwave heats much slower when on a 2kW Modified Sine Wave inverter, and my automatic Nespresso machine won't even start.

That I'd expect as they both use wound components.

I take your point about phase control but effects will be harmless and simply point to the need for a true sinewave inverter. For the many (most?) who don't have anything that needs true sinewave fitting one is simply added expense.

 

[TheBig1]

I plan to link it to the batteries with a separable plug or switched so it's completely isolated when not in use.

Replace those small cables with more like twice the thickness. You can use the originals to link the second battery. And add a battery isolator switch to the black wire connecting to the inverter. They are only £5 or £6 on ebay but can handle 200amps

 

[funflair]

That I'd expect as they both use wound components.

I take your point about phase control but effects will be harmless and simply point to the need for a true sinewave inverter. For the many (most?) who don't have anything that needs true sinewave fitting one is simply added expense.

Or is it false economy not fitting pure straight away, our van came with modified wave inverter but the microwave was useless and the Nespresso machine even worse and they were the first two things that I wanted to run, so I changed it for a pure and I now know that I can plug in anything I like.

Martin

 

[tonyidle]

Or is it false economy not fitting pure straight away, our van came with modified wave inverter but the microwave was useless and the Nespresso machine even worse and they were the first two things that I wanted to run, so I changed it for a pure and I now know that I can plug in anything I like.

Martin

It depends on need. Quite often a request for help on here is quite specific and only mentions a couple of items. I totally agree that if aiming for 1000W+, and especially if considering a fully installed system, a pure sinewave is the better option.

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[DBK]

I'm rather at a loss to understand why any modern electronic device would be affected (in any way that would cause damage) by a modified sinewave inverter. Earlier devices used a transformer in the power supply that won't work with a modified sinewave device and rechargeable toothbrushes still do but pretty well anything else is powered by a switched mode power supply. A switched mode PSU output is chopped DC followed by whatever smoothing can be crammed into the wall wart or other small plastic box. At the other end the input to the PSU is rectified and stored in a large (-ish) capacitor. What exactly is the likely effect of using a modified sinewave inverter on, say, a laptop? I should say I've seen no effect on anything (other than a toothbrush).

This is one explanation. It may not be complete but makes some useful points. https://www.lifewire.com/modified-sine-wave-inverter-damage-question-534760

 

[tonyidle]

This is one explanation. It may not be complete but makes some useful points. https://www.lifewire.com/modified-sine-wave-inverter-damage-question-534760

Pretty well as I suggested. Doesn't mention toothbrushes though.