Any reason NOT to just buy a cheap portable inverter?

[svfinlandia]

Originally Posted by StuM

The link is to a MSW inverter (modified sine wave)
It depends on what you are going to use it for.

See for instance:
https://invertersrus.com/pure-sine-vs-modified-sine/

Some devices and appliances that require a pure sine inverter are:

• Microwaves
• Laser printers
• Variable speed tools
• Cordless tool battery chargers
• Some TV’s
• Key Machines
• CPAP machines with humidifiers
• Medical equipment
• Sensitive electronics

+1 on this!
I would be sure to buy a true sine wave inverter. Modified inverters put out an ugly looking square wave with spikes and are really hard on equipment.

Al, S/V Finlandia

[Boatyarddog]

Originally Posted by aisleorwindow

Thanks for all the help. Was not aware of the different sine waves, so that's quite useful.

To clarify, I just would plug into the 12V, would NOT be wiring directly to the battery.

As long as you use a proper fuse to protect your 12vt, socket.
Pure sine wave is a full wave, like what comes out of your house plugs, in the USA.
Modified sine waves have the wave top cut off. Efficiency is the result and cooler running apparatus.

https://m.youtube.com/watch?v=B-xO8-uMFNw

Boatyarddog

[goboatingnow]

Originally Posted by Rumrace

Yes a couple dozen.

At any rate make sure it’s for marine. A car battery charger will cause metal damage to anything in the water. You can get a simple charger inverter for a single battery with a 120V outlet around 40$. For 75$ You can plug in solar 120V charging charging, and two outlets.

It’s equipment for bass boats. They have tiny marine units. I’ve seen them on amazon and Westmarine.

I doubt there is such a thing as a “ marine “ inverter

And as to how an isolated device can’t cause “ metal “ damage ???

[Boatyarddog]

Originally Posted by goboatingnow

I doubt there is such a thing as a “ marine “ inverter

And as to how an isolated device can’t cause “ metal “ damage ???

There is this.
https://www.boatsafe.com/best-marine-power-inverter/
Boatyarddog

[Boatyarddog]

Originally Posted by svfinlandia

+1 on this!
I would be sure to buy a true sine wave inverter. Modified inverters put out an ugly looking square wave with spikes and are really hard on equipment.

Al, S/V Finlandia

Costs are definitely higher with pure sine, I've not had any problems with a modified sine, inverters.

I do not use a laptop on the boat although, or have sensitive equipment.
I did notice a slower start up on rotational motor equipment though a
Mikita angle grinder.

I attributed that to 1000w peak output rather than a sine wave difference.
I think a 2000w unit wouldn't do that.

A non charging/inverter model cannot damage any metal on the boat.
Boatyarddog

[zstine]

Originally Posted by aisleorwindow

Have been looking at just getting a basic inverter to plug into my 12V just for simple charging of phones/laptops/etc while under motor.
At present, we don't spend long periods of time on the hook - mostly just day sailing in Lake Michigan.

Is there any reason not to buy a super simple "cheap" inverter like this one:
https://www.batteriesplus.com/produc..._term=PWR10017

I like having something small that I can store easily, and like the idea of being able to use in the car as well if needed.
But I don't want to be "penny wise and pound foolish" either, so very open to feedback.

Why use an inverter to go from DC to AC back to DC? If you want to charge a laptop, phone, etc... get a DC to DC laptop charger or something like DC to USB (65Wmin to charge laptop). Much more efficient. less prone to problems


https://www.amazon.com/Universal-Cha...s%2C75&sr=8-10


OR


https://www.amazon.com/Charger-Cigar...s%2C109&sr=8-6

[Wayne Bostow]

ANY inverter use will void the warranty on anything you plug into it.

[Boatyarddog]

Originally Posted by Wayne Bostow

ANY inverter use will void the warranty on anything you plug into it.

As I don't agree with this statement, could you cite your source for that statement.
I've never heard of this issue.

How would anyone know where you plug it in.

And if it's a pure sinewave inverter.
There is no difference in power quality.
Boatyarddog

[jmschmidt]

Most electronic do-dads can be charged on 12VDC systems. That's what the charging ports in your car do.

[StuM]

Originally Posted by Wayne Bostow

ANY inverter use will void the warranty on anything you plug into it.

So you have no warranty on any appliance if you live off grid with solar etc as your primary power source?

Yet another totally unsupported contention that flies in the face of facts.
Why is it almost always in electrical threads that we see this sort of noonsense?

[StuM]

Originally Posted by jmschmidt

Most electronic do-dads can be charged on 12VDC systems. That's what the charging ports in your car do.

Many (most?) electronic do-dads using batteries require voltages other than 12V.
(5 and 18-19 are VERY common) The "charging ports" (I still call them cigarette lighter sockets ) are 12V - you generally need a DC-DC converter to charge from them. Something like this (although this one is "buck only", not "boost":

[Colin Stone]

I just use a cigarette type QC3 12-24v USB charger in socket.
For laptops, 19/20v, and satellite receiver 12v, DC - DC converters, up and down, from the battery voltage.
12/24v up to AC and back down to 5v doesn't seem to make much sense for just charging phones etc. If inverter is on for something else, then fine.

[wholybee]

Originally Posted by Rumrace

Yes a couple dozen.
At any rate make sure it’s for marine. A car battery charger will cause metal damage to anything in the water. You can get a simple charger inverter for a single battery with a 120V outlet around 40$. For 75$ You can plug in solar 120V charging charging, and two outlets.
It’s equipment for bass boats. They have tiny marine units. I’ve seen them on amazon and Westmarine.

He is looking for a standalone inverter, not an inverter/charger. It won't be connected to the AC system on the boat, or the boat's AC grounding system. Just plugged into a 12v socket, with a phone charger or similar plugged into the inverter. So those issues do not occur.

With that in mind, there are some good reasons to have a small inverter. Large inverters are very efficient when run at higher loads. But, my 3000W pure sine wave inverter draws 0.5A with nothing plugged into it at all. That's terrible. If I am charging something at <100W, using a small plug-in inverter uses a lot less power than my 3000W inverter.

But, the OP should look for a pure-sine wave inverter. More and more often, newer electronics need it.

[SOLAR SUPPORT]

I use a small and simple second inverter with a power of 150 W on my boat. I comfortably use laptop, TVBox, mobile phone and other small 220V chargers. Even at idle, large inverters consume 1.5-2% of the total power. Using a second and small inverter for small power needs creates an advantage in this respect. In order to test an inverter of the same power and wave type but very cheap compared to others, you can use simple and inexpensive devices that measure 220 volts of power, but with precision. After plugging this device into the 220V outlet of the inverter, plug a device with a label showing the power level in watts to the power meter. If the power seen on the meter is the same or very close to the power indicated on the device's label, the AC energy produced by this inverter is of good quality. By measuring the DC consumption of the inverter, you can also control its efficiency. Some 110-220V AC powered tools may need pure sine types.

[Eight Sails]

Originally Posted by thomm225

So I was thinking it was like this

https://www.donrowe.com/Samlec-SAM-4...iABEgK1h_D_BwE

with battery lead attachments and no fuse.

I've used an earlier, 350 watt version of this Samlec inverter on my boat for a number of years and it works fine.

Although a 12V USB charging socket is undoubtedly more efficient than using an inverter to charge small electronics like a phone or Raspberry Pi, it's handy that the Samlec, for one, includes a USB charging port in addition to two AC sockets. An inverter this size is small enough to mount out of the way under the chart table and any kind of cord can plug into it -- 110V plug for a laptop, USB cable for a phone, whatever.

Having used a cigarette lighter-type 12V socket over the years to charge everything from Pocket PCs and phones to netbooks and laptops, I've never liked that solution--way too loosey-goosey, with a heavy charger hanging off the socket and flopping around in rough weather. Replacing the lighter socket with a USB outlet is better, if all you need to charge is a phone or tablet.

For powering/charging anything bigger than a phone or tablet--i.e. anything that needs a power brick--you need the inverter. I don't like running the engine more than I have to, just to charge the house battery, so I favour a small inverter and fewer, smaller electronics. YMMV

Battery clamps aren't an acceptable permanent solution for wiring even the smallest inverter. If your boat is insured and you will ever need to get a survey done, take the time to hard wire the inverter and ditch the clamps. Size the leads correctly and put a fuse in the positive circuit -- I used 8 AWG marine grade wire and a 50 amp maxi fuse in a 30-80A block, following the specs in the user guide.