How many amps does my inverter provide

[opnspaces]

If I have a Zamp ZP-300PS or a P-600PS pure sign wave inverter, how many amps does it put out at 120 volts?

Am I calculating correctly at 300w \ 120 v = 2.5 amps AC?
If I use a 600W inverter then am I only going to see 5 amps AC?

The ultimate question is; if I want to plug a computer power cord (18/3 x 18 inches) to power something, is the 18 gauge heavy enough to prevent melting down the cord? Keep in mind that this is power coming out of either the 300 or 600w inverter and not coming from a city utility line. Below is the spec sheet for the two inverters.

[landyacht318]

The blue insulated 'quick connectors' which are provided with these USB sources, and some of the 12v combo panels with voltmeter and switch and USB and 12v port, are very poor. They are not tin coated brass or aluminum even, but some other metal, and the blue plastic shears apart when crimping and they cannot properly clasp the tangs.

Do not use them or even keep them for a 'just in case' situation.

I dislike crimping insulated terminals even with the correct dies to do so, and usually remove the plastic/nylon insulation, then crimp, and solder over the crimp, then heatshrink, usually two different length layers of heatshrink. Much more time consuming but much more reliable.

Lately I've just been soldering wires to the tangs, as I am out of the quick connects, and don't feel like going to acquire more, or placing an order.

The parasitic draw of my 8 year old Blue Seas 1016 USB is somewhere under 0.01 amps. It has a small green LED, but that 5vDC is always there, so the device is always converting 12.xvdc to 5v even with no usb cords inserted or devices asking for juice. I am 24/7, but not always 365. I have in the past pulled the usb fuse when away, but not so much because of parasitic drag but to extend the life of the USB and peace of mind while away.

As GTE says my Ciggy 12v receptacles have rarely been the issue, always the plug, but one is worthless without the other in most instances, the USB source being an exception, and they are an unreliable mechanical and electrical connection at best, and deserve zero praise.

It's disappointing to see this horrible ubiquitous connector get any. Any that have not failed, simply have not failed yet.

I've had a few which came with higher draw devices which eliminate the internal fuse, and some even have the glass fuse's endcap soldered directly to the wire inside the plug. Poorly soldered, and the failed fuse still appeared unblown.

The most failures of plugs were of the exploded view design that GTE posted. The spring got so hot it changed color lost its spring and the spring and spring holder melted into the plastic. That was powering this laptop's 90 watt DC to DC powerbrick streaming some HD video. Two of them failed, and the second replacement, was provided for a 400 watt inverter, but came with a sticker on it saying to not use it for more than 120 watts, and it failed at just over half that current.

Blue seas make their own plug version one inserts their own upto 14awg wire into, and I forget what I was powering but it also melted. I still use them where simply pushing on the connector to seat it and pulling it out slightly is convenient or I want something fused while testing boosters or buckers, but even here they have proved more trouble than they are worth.

When there is a high pitched whine coming from within a connector when a PWM led dimmer or motor speed controller is being powered through it, then it is obvious the connector is ****, no matter how much faith one might have in it, or how much they dislike me.

Avoid the ciggy plug and receptacle whenever possible. Even when used at half their 'maximum' rating, they will fail, its just a matter of time.

[Gdetrailer]

opnspaces wrote:
Thanks for continuing the discussion Landyacht and Gdetrailer. I have a clarifying question.

I do use one of the mentioned plug in adapters to charge my phone while driving. And yes over time the plug vibrates out and I have to push it back into the socket. And I agree this is not the best solution.

I'm a bit confused though on the use of the USB port. In my rear power panel I used something like the picture below with the power wires attached to the rear. Are you guys saying that using this type of plug is also bad and should be avoided?
Link to plug I used

No, the "bad" discussion is is not with the "adapter" you are using, LandY's beef is with using a regular cig lighter plug in..

Here is a pix of the back of your 5V adapter..



What you selected is not the same as a cig adapter and is a permanent mounted hard wired device.

What I will say though with your device they show the connection can be made with slide on connectors which you crimp the wire in the connector then slide the connector onto the device..

To me, those connectors are far, far worse of a connection since you now add a handmade crimp and a friction slide fit of the connector.. In your case, low enough wattage, most likely will not present a problem but once again adds potential of issues down the road.

IF you have a good soldering iron and some rosin core solder for wire and some heatshrink wire I would skip the slide on connector route and directly solder the wires to the device if the terminals offer a small hole to thread the wire through. Gives better mechanical and electrical connection and results in best reliability.

I would also suggest setting your outlet up with a on/off switch or at a minimum connect to a switched power source that only supplies power when vehicle key is on (ACC or Run).. Reason for this is this little outlet while it looks harmless WILL become an additional small Phantom draw from the battery.. If the vehicle sits for a long enough time the extra draw combined the vehicles electronics draw can flatten the starting battery..

That is why most newer vehicles now manage the cig lighter power ports via Body Control Module and will shut it off after 10 or 15 minutes after key off..

[opnspaces]

Thanks for continuing the discussion Landyacht and Gdetrailer. I have a clarifying question.

I do use one of the mentioned plug in adapters to charge my phone while driving. And yes over time the plug vibrates out and I have to push it back into the socket. And I agree this is not the best solution.

I'm a bit confused though on the use of the USB port. In my rear power panel I used something like the picture below with the power wires attached to the rear. Are you guys saying that using this type of plug is also bad and should be avoided?
Link to plug I used

[Gdetrailer]

landyacht318 wrote:

You say 80 watts is their continuous duty limitation, I say 60 .Many 12v receptacles will say 120 or 150 watts maximum, but this is wishful thinking and one best enjoy the smell of melting plastic if they are intending to ask them to pass this much current for more than a minute.

In the olden days back when vehicles were built of all steel and the dash was all steel with a little hard plastic top, those cig lighter outlets were truely designed to handle up to 15A.. They had to, since every car which was equipped with one of those came with a cig lighter that you pushed in to heat and it would pop out when ready for you light your cig..

Those outlets were fused at 15A on the BACK of the outlet which is 180W for your information. Pop that fuse and you had to remove the outlet from the dash to replace.

Yeah, I do have a 1970s car with one of those and I still have the cig lighter that goes in it..

Have used heavy spot lights in that along with those 1970s 12V vacuums (they made more noise than they did actual work), 50W Mobile two way radio telephone (think like "5 O" TV series when they wanted a phone patch), CBs, 50W 2mtr Ham radio equipment, .5 cu ft 12V absorbsion fridge and even used 12V air compressors to fill low tires..

I have never had burnt contacts in any of my vehicles or any other calamities that you mention.

Keeping in mind that they were NEVER designed for 24/7/365 permanent high power use, they were designed for a quick high wattage burst then off (think as in how the old fashion cig lighter worked) they provide a universal power port which is readily available, easy to use and pretty much every vehicle in the world built since the 1990s come with at least one as a standard item.

The issue you have had is not the socket but the PLUG, not all plugs are well designed and that IS the problem you have had..

Cheap plugs have very poorly designed negative contacts, often not much more than a light ga wire with barely enough spring load to prevent the plug from backing out..

The fix is easy, change the plug..

There are better plug designs which have a wide contact area on the negative contacts which have a higher spring load.. Those do not backout easy and are often rated 15A or better.



And for the record, a few years ago when "car PCs" were the rage and laptops were insanely priced, I built a poor mans car PC for my DD to use while traveling.. Found a low power system board with a 1.6ghz Atom processor (27W for the system board), 500 GB HD a 12" TV with VGA input and ran it off a 400W inverter.. All told the PC wattage with the TV monitor was just at 80W.. Yeah, didn't burn up the plug or outlet, didn't have any issues with PC quitting either..

[landyacht318]

I still employ ciggy receptacles, and plugs and have highly capable 2 usb chargers which fit into them. I know they wont approach the wattage level where the receptacle or plug itself is in danger.

Pulling out the usb plug from the socket just enough to eliminate the parasitic draw is easier than rigging up a switch or pulling the fuse.


You say 80 watts is their continuous duty limitation, I say 60 .Many 12v receptacles will say 120 or 150 watts maximum, but this is wishful thinking and one best enjoy the smell of melting plastic if they are intending to ask them to pass this much current for more than a minute.

But they also can rattle/ workl their way out of the plug under light wattages, and if they are somewhat looser than perfect, can emit more RFI noise and cause some USB charged devices to act weird, stopping charging or saying they are full when they are not or saying they are charging, when they are not.

Having a USB ammeter and some tv channels prone to interference from DC to Dc converters, i can say with lots of experience, that the worst choice for fast reliable charging of my USB devices with minimal possibility of screwing up my actual channel 8 or actual 10, is the USB plugs inserted into 12v ciggy receptacles, where the hardwired one while in a somewhat less convenient location, rarely knocks out the Tv channels.

I also have the PWR+ Dc to Dc laptop car adapter powering this laptop I am wringing on right now, it is likely a decade old, it is rated at 90 watts, though the average draw is 32 watts typing like this with two tabs open. Solid 60 watts or more is for dvd watching or streaming HD, or some other more intense CPU consuming tasks.

I've been calling people crazy for 10+ years for insisting they need an inverter to power their original AC to DC powerbrick, when DC to Dc converter 'car adapter' is significantly more efficient and reliable( once ciggy plug is eliminated) at performing the same task.

The original ciggy plug on my PWR+ car adapter melted arounf the internal fuse in a month, its replacement lasted 2, and the third I bought, but never employed a '12 amp' Blue seas and mating blue seas receptacle which has proven to be problematic too powering other things
I've since switched to Anderson powerpoles and not an issue since in the subsequent 9+ years, with the input side. I have had issues with the 19.5v dc output wires. My Dell uses 3 wires and the barrell connector has a small pin in the middle. the thinner 3rd wire to this pin would break internally and the laptop would not charge.

the 150 watt DC booster I linked would work fine to power my laptop, but the laptop battery will not charge.

I use the dc to dc 150 watt booster for many things, like charging 24v Nicad battery packs or charging my 18Ah AGM at 14.7v while my regular battery is being held at 13.6v by my solar and it has exceeded that 150 watt rating for a good while without issue, but I did add a 60mm fan bridging the heatsinks. It's installed within some old inline ventilated powerbrick housing for some forgotten device.

I've used it often for bringing 12v batteries upto 16.2 volts for an equalization charge. Its honestly among the best and most useful sub 3$ purchases I've ever made

In short while 12v receptacles and some plugs can work 'just fine' for low draw devices for some period of time, they are an unreliable connection that adds more resistance than needed for the task at hand. Just because they are ubiquitous worldwide does not mean they are some greatly reliable connection.

In my opinion they are best eliminated from anything requiring reliability and maximum efficiency, even if the wattage they are asked to pass is well below their 'quickly troublesome' range.

I've experimented with them, running 10AWg to the receptacles and the plugs, and seeing how hot they get passing various amperages. It was a waste of solder and 10AWG and confirmed my suspicions, that they are always best eliminated on any circuit requiring reliability and efficiency

I do still employ them. they are convenient, but I feel 60 watts is their continuous duty limit, and only when well wired, and somewhat new with the ground springs roughed up a little to grab the side walls of the receptacle tighter, and the spring loaded nipple tip kept clean, Caig Deoxit d5 clean, and the spring lengthened a bit and somewhat regularly to keep it pressed tightly against the back of the receptacle.

I rarely ask mine to exceed 20 to 25 watts, powering leds, fans or these USB chargers, but when the LEDs start changing brightness, it is almost always remedied by pushing the plug back deeper in the receptacle, and if channel 8 or ten start pixellating and stuttering, pushing them deeper in their receptacles more often than not allows the tv signal to come though unadulterated with noise generated from poor spring loaded connections from some horrendous electrical connection designed 75 years ago. I am not powering the TV through the USB receptacle or the same wiring even feeding the USB/ciggy plug. It kills the reception even if They are powered by different batteries.


You of course are welcome to your opinion, I was not attacking your product recommendation, I employ two very similar products. I was only sharing my experience having used them widely, pushed them to and past their limits with various designs and various gauges of wires entering receptacles and leaving the plugs. measuring the heat voltage drop and seeing whether they would knock out my channels 8 or ten and whether at that moment when they would, if bypassing the ciggy plug and receptacle itself allowed 8 or ten to be watchable. Much more often than not it did.

Ciggy plugs/12v power ports plugs and receptacles are horrible unreliable electrical connections, best avoided whenever possible. the more current they are asked to pass the more important it becomes to have a back up connector on hand for their inevitable failure, as it is not a matter of if, but when, they fail.

So Instead of having to fix things at the most inconvenient time possible to do so I recommend not having to fix it at all by eliminating the problem prone device in the first place instead of learning the hard expensive time wasting and material wasting way of those of us who have been there and have done that and never want to have to do it again.

Eliminate the Ciggy plug/12v power port receptacle whenever possible, especially in the product planning stages.

[Gdetrailer]

landyacht318 wrote:


I recommend skipping the Ciggy plug whenever possible too, It is a horrible, contemptible, highly resistive electrical connection, that gets worse with age and the more current it is asked to pass. I've had one of the supposedly 'better' ciggy plug and mating receptacle buzz audibly when using a PWM dimmer on some leds, and could stop the whine/buzz simply by changing the pressure on the plug, but as soon as I let off it came back.

There are USB receptacles designed to fit the same space as a ciggy plug 12v receptacle, This one shows Amps( @5vdc) as well as voltage reaching the plug.

I considered posting about the built in USB charging ports but really didn't know exactly the OP's full intentions so ruled in favor of a Cig lighter plug style for ease of installation, portability and ease of replacement if it dies, not to mention fairly inexpensive.

In reality, 12V to 5V USB chargers will not draw enough amperage to be a issue with burning or melting plug or socket contacts.

I realize cig lighter outlet contacts are not all that great, but most vehicles have them built in and typically they work reasonably well provided you don't make a habit of drawing 80W or more from them

Dual 2.4A 5V ports should be a max of 57W (approx 4.75A) which is below the max rating of most cig lighter outlets.

Keep in mind, pretty much most of the time most devices will draw not much more than half amp to maybe 1.5A at 5V and even if it did draw 2A at 5V it would be a very short time when battery is fully depleted.

So, unless you are attempting to run a high wattage inverter with a 80W or higher load a cig lighter port WILL work fine for most loads of less than 80W.

In fact, most laptops now days come with 40W-60W power supplies so you can buy generic universal 12V to laptop power supplies (12V battery voltage in and 16V-21V output selected by the tip you install)up to 90W which will not have any issue with using a cig lighter port.. Like this.



I HAVE done that on a i7 Quad core 2ghz processor 2 in 1 laptop/tablet with touch screen with a TB SSD drive (eats battery)and it worked flawlessly!

I am not a fan of running a 12V to 120V inverter and then plug in a simple phone/tablet 5V battery charger.. Too many conversions = wasted energy in heat. Just not the right tool for phone charging.

[wopachop]

I bought one of those panels a couple years ago. Was going to cut a 4" square into the side of my cabinet. So glad i never pulled the trigger. For me the switch and voltmeter never gets used. Might eventually cut a 1" hole and install just the USB.

Another idea for people in the market is to purposely buy a 1a USB outlet. Because some devices claim to only use the included charger which is sometimes only 1a. That was the case for my Verizon jetpack wifi device. Sales guy said they get a lot of returns because people cook and expand the battery from using too high of charge. Same with the wireless ear buds i just got. I have them plugged into the inverter using that white charge block that is only 1a. So it would be kinda nice to have a low power 1a USB to accompany a dual 2.4a (or whatever is highest right now...got to think some can now do 9v fast charge). I personally would like a dual 1a USB and a dual 2.4a. With also the inverter to charge laptops when not on shore power.


Here my procrastinating setup. Just kinda free willy nilly for a good year or two. I push them back behind the lip while traveling.

[2oldman]

Sine wave, not sign wave.

[opnspaces]

RoyB, I love the panels you posted, I never even imagined they existed. I will definitely get one for my trailer in the future.

[opnspaces]

You guys are great. Landyacht, Gdetrailer, RoyB, DrewE, wa8yxm, Ca Traveler, Wopachop, ndrorder, I love all the suggestions and pictures to go along with them. I actually have a few of the exact USB adapters that Gdetrailer posted. You'll see it in one of the pictures below.

Here is where I have to admit to my mind being in a different place when I created this original post. Because of this I incorrectly stated the reasoning behind adding the inverter. So I'll try to clear it up here and show what I was doing.

Aside from being a tow vehicle, my Suburban is the family road trip vehicle. With 4 boys of my own, plus 8 nephews and 1 niece (all teenagers) there can be any different number of kids and their electronics in the vehicle at any one time.

In the rear cargo area of the Suburban I have an Intel NUC mini computer running both PLEX and PlayOn movie servers with over 400 movies stored. This is hard wired to an ASUS wireless router that the kids can link to in order to watch movies. This combination of computers plus 8-10 different USB plugs is what the inverter and a power strip is really for.

This week I finally removed the original factory stereo and installed a touchscreen unit with a backup camera. This made the rear audio controls in the center console obsolete. And since I have a 3d printer I decided to remove the audio controls and make a panel for some outlets.

The inverter in the center console and powered off of an ignition on fuse. The console is all plastic so there is no metal to short to.


Here's the original and now obsolete audio panel (truthfully we never used it)

The 3d printed patch panel.

And finally everything put together and powered.


I decided to run the 300w inverter powered off a 15 amp fuse. If the kids blow the fuse it they will have to decide how to better ration the available power.

[ndrorder]

Since the surge of the 600W model is 1200W, a 7Amp inline fuse to protect the 18 ga. wire is a hands off approach to not overloading the wire.

[RoyB]

If you are just wanting POWER STATIONS these panel would be ideal... They connect directly to your Batteries and can be mounted almost anywhere. I would get one with an ON-SWITCH as if you have a digital readout the panel may be very bright being left on 24/7.... These are very inexpensive panels and can be mounted either horizontal or vertical... Most of these panel kits come with wiring cables etc... Check out on AMAZON for 12VDC USB SOCKET PANELS...


google image


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Using a POWER INVERTER for something like this will most likely get you in an discharged battery situation.

Roy Ken

[wopachop]

Gotta love when landyacht replies!! Learned a ton from you dude.

[landyacht318]

Another case of the inverter not being required to do the task at hand.

Anytime one can bypass the requirement of having to use the inverter it will likely save both money, and battery power.

I recommend skipping the Ciggy plug whenever possible too, It is a horrible, contemptible, highly resistive electrical connection, that gets worse with age and the more current it is asked to pass. I've had one of the supposedly 'better' ciggy plug and mating receptacle buzz audibly when using a PWM dimmer on some leds, and could stop the whine/buzz simply by changing the pressure on the plug, but as soon as I let off it came back.

There are USB receptacles designed to fit the same space as a ciggy plug 12v receptacle, This one shows Amps( @5vdc) as well as voltage reaching the plug.

https://www.amazon.com/Charger-ADSDIA-Aluminum-Waterproof-Motorcycle/dp/B07PN5YZX3/ref=sr_1_5?keywor...

Shop around, that was just the first hit that looked like the product I have in mind and have employed on a friend's rig.

I've installed a few of these in a friends vw bus and they do recharge his Kid's ipads at a high rate. The voltmeter and ammeter display is kind of a novelty, and is difficult to see when there are two usb cords installed in it. These do have a very small parasitic draw when they are not charging anything, somewhere under 0.01amps. Use a switch in line, or be able to pull the fuse easily, for storage mode.

The inverter is wasteful when powering 5vDC USB ports or a 19.5vDC laptop. One can get dc to dc 'car adapters' for their specific laptop for about 25$ or less, and save 5 to 15 watts of energy over using the inverter powering the provided AC/DC power brick.

150 watt DC boost converters can be had for about 2$, if one has some DIY skills.

https://www.ebay.com/itm/1pcs-150W-DC-DC-Boost-Converter-10-32V-to-12-35V-6A-Step-Up-Power-Supply-Mo...

Inverters are a necessary evil, but in my opinion, should always be the last resort, not the go to solution for everything household on battery power.