Inverter needs-how much

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John Smith

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I need to charge 24V batteries so a pure sine wave was needed. A small 600 watt unit was simple to wire off the main battery, has a small foot print. It well not run a coffee maker.
Is there any need to use it as a 24 V battery? If you use them as 2 x 12 V batteries you'll have twice the amps.
Or did I get something wrong?
 

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This is the inverter I plan to buy. My 2 batteries are not connected to the car so the solar will connect directly to the batteries I'm guessing. I'm even more confused by some of the answers I am getting. Here is the converter and a video supplied by Harbor freight.
I am sure you can find a nice diagram on how to set things up but the basics are:
1-2 Batteries
Solar Controller to charge batteries
Solar Panel of your choice (100 watt or better would be my recommendation)
A Fuseblock (Bluesea for example) to connect USB plugs, and anything else 12 volt
Inverter direct to the battery (Should have a fuse)

Bonus items (On off switch to turn everything completely off) OR
Battery switch that allows you to get power from battery 1 or battery 2, or both. (Blue Sea Systems 300 Amp m-Series Battery Switches)
Shore power so you can plug in and charge batteries at home (Noco brand work well)

In the Southwest I think 2 batteries are overkill because solar works so well. I have a 95ah starter/deep cycle battery in my FJ and another 95ah deep cycle in my trailer. My 100 watt panel can keep both happy while camping in a matter of hours. I manually switch my fridge to be powered off of the trailer battery when I am base camping.
 

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It seems like most of what you want to use will be 12 volt (including a future fridge). Build yourself a nice DIY charging station that has lots of USB ports. I have a 12 volt charger for traditional rechargeable batteries (flashlights) so I don't have to use 110. I tend to charge my portable HAM radios with the traditional home chargers vs 12 volt.

I don't think you mentioned if this needs to be in your vehicle or a trailer. That also might steer you one direction or another.

Air Pump - If for an air mattress then yes inverter required - If your vehicle has a 110 outlet then you wouldn't need an inverter for that.
Ween the kids off of TV when camping! Then no power required for that. :)
Coffee there are plenty of options that don't require bringing the counter coffee maker (heck there is an entire thread for this!)

I guess what I am getting at is there are a lot of alternatives to power items via 12 volt vs 110 and sometimes you should just leave some stuff at home. But hey that's me.
Totally agree. Most of my examples are situational, I haven't had to use half of the equipment I bought in an actual camping situation inside of my truck camper shell setup. I just like to have the options of 12v and 110 should I need it for whatever reason. My coffee maker is something I have from tent camping. I do have a proper kettle should I need hot water, which I would heat up with my propane setup.

I have so many use cases for my truck camper other than 'overlanding'. I use it for sporting events for the kids, weekend get-aways to our timeshares, and prepping the truck for bugout situations should the situation arise. Sometimes I just let the kids just watch TV inside the truck in front of our house for the heck of it. It's also my man cave so again, many uses other than just one build for 'overlanding'. Like my co-worker says, you love your truck.
 

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One important factor with microwaves a general rule of thumb for wattage. What ever the OUTPUT wattage is , it is twice that for input and usage. ie. if you have a small microwave with 400watts like I have it takes 800watts to run it. And it does make the meter spin, for short term use only. And make sure you get a pure sine wave. A good place to shop is Donrowe.com. Good prices and great tech support for your project. I run a Kisae 2000w pure sine wave with 2 group 31 AGMs, Blue Sea System ACR, 20A Xantrex Marine Charger for shore power, and a 125w solar system that I am going to upgrade to 185w that brings in around 8A to 10 with the 185w. Blue Seas Systems web site has chart of what gauge wire you will need for your inverter install, don’t skimp and keep the run short as possible.
 

Lanlubber In Remembrance

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You will have to use a solar charge controller for charging the batteries. I am using the ones from Victron Energy in 2 rigs.
And still it depends on what you plan it to use for.
If it was my post that confused you please forgive me ;). My english lessons were a long time ago.
John, the harbor freight 100w kit comes with the solar charger. The instructions tell me all I need is an inverter and a battery to complete the circuit and have electricity. I plan for longer stays than most people when I go off grid so I purchased 2- 1000w - 27 series deep cycle marine batteries. Now I need the inverter but they didn't give me a clue as to what size inverter I need to complete my package. I listed in another post what equipment I plan to use. The video posted on the inverter seems to indicate I can run just about anything on a 750w sine inverter adequately. Your English is fine for me. I can speak no other language so I am always impressed if someone speaks more than one language, that's cool. Thank you for your input, I feel the OB people will guide me in the right direction since most have far more experience than I.
 
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bmwguru

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One important factor with microwaves a general rule of thumb for wattage. What ever the OUTPUT wattage is , it is twice that for input and usage. ie. if you have a small microwave with 400watts like I have it takes 800watts to run it. And it does make the meter spin, for short term use only. And make sure you get a pure sine wave. A good place to shop is Donrowe.com. Good prices and great tech support for your project. I run a Kisae 2000w pure sine wave with 2 group 31 AGMs, Blue Sea System ACR, 20A Xantrex Marine Charger for shore power, and a 125w solar system that I am going to upgrade to 185w that brings in around 8A to 10 with the 185w. Blue Seas Systems web site has chart of what gauge wire you will need for your inverter install, don’t skimp and keep the run short as possible.
That's a nicely setup system. Only thing I think I would add is a DC to DC charger to top up the batteries while on the move. I am looking at the Redarc 25a dc/dc charger. It has an mppt solar controller built is as well. Dual Input 25A In-vehicle DC Battery Charger
 

Lanlubber In Remembrance

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Will was my main inspiration for my solar build out in my truck. Wealth of knowledge for a young guy.
This is the site I watched. It is for beginners like me. Everything is clear and understandable. I learned a few things I was not aware of besides the inverter. For those who are thinking of doing something similar, here is the site.


 

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This is the site I watched. It is for beginners like me. Everything is clear and understandable. I learned a few things I was not aware of besides the inverter. For those who are thinking of doing something similar, here is the site.


This is his video that I based my build off of.

 

Lanlubber In Remembrance

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One important factor with microwaves a general rule of thumb for wattage. What ever the OUTPUT wattage is , it is twice that for input and usage. ie. if you have a small microwave with 400watts like I have it takes 800watts to run it. And it does make the meter spin, for short term use only. And make sure you get a pure sine wave. A good place to shop is Donrowe.com. Good prices and great tech support for your project. I run a Kisae 2000w pure sine wave with 2 group 31 AGMs, Blue Sea System ACR, 20A Xantrex Marine Charger for shore power, and a 125w solar system that I am going to upgrade to 185w that brings in around 8A to 10 with the 185w. Blue Seas Systems web site has chart of what gauge wire you will need for your inverter install, don’t skimp and keep the run short as possible.
The inverters I am looking at are sine wave. The inverter I am looking at has a continuous rating and a peak rating. I am assuming the reason for the peak rating is for when a microwave needs that extra wattage. Is that correct ? You have a better system than I have . The harbor freight system I purchased can be added on too up to a point.
Thank you for your input, it was helpful.
 

John Smith

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If there is some interest I'll post some photos of te setup in my VW T4 tomorrow.
I have an 230W rigid solar panel on top, a Victron Energy solar charger and a "refreshed" 115 amps battery from the scapyard inside. The inverter I am using is 3000W sinus continuous and 6000W peak.
I am able to use a concrete (hand) mixer on it. But on the other side a water boiler doesn't work. It's all depending on the watts used an in my case the age and the c-rate of the battery. My battery isn't fit enough for my inverter at max. power.
For lights, a small coffee machine, refrigirator and usb chargers it still is far enough.

The peak wattage of an inverter is only for "starting" wattage. For example my small concrete mixer is rated at 1500W but needs approx. 2500W for starting during a brief period.
For everything that lasts longer it shouldn't be above continuous wattage.
 
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The inverters I am looking at are sine wave. The inverter I am looking at has a continuous rating and a peak rating. I am assuming the reason for the peak rating is for when a microwave needs that extra wattage. Is that correct ? You have a better system than I have . The harbor freight system I purchased can be added on too up to a point.
Thank you for your input, it was helpful.
That is incorrect. Look at the continuous rating. All electrical products have a UL label on them, usually on the back or bottom this will tell you the wattage. I will use a heavy draw one at a time, make the Wifes coffee, the coffee maker is 650W then I use the micro the warm the creamer for about 30 sec. that draws 800w. If you use the them together add up the wattage. Peak wattage is a bull sh*t spec. they use in advertising to make it look bigger. They do it with boat depth finders, stereo equipment all sorts of stuff. Any questions I will be glad to help. I used to do this for a living.
 

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That's a nicely setup system. Only thing I think I would add is a DC to DC charger to top up the batteries while on the move. I am looking at the Redarc 25a dc/dc charger. It has an mppt solar controller built is as well. Dual Input 25A In-vehicle DC Battery Charger
The ACR , automatic charging relay, links the trucks alternator to the AGMs when the truck is running the disconnects them from the truck system when I turn the truck off so my start battery isn’t effected while camping. They are by Blue Seas Systems you can find them on Amazon for around $100. They are called ACR battery links. Pretty cool.
 

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The ACR , automatic charging relay, links the trucks alternator to the AGMs when the truck is running the disconnects them from the truck system when I turn the truck off so my start battery isn’t effected while camping. They are by Blue Seas Systems you can find them on Amazon for around $100. They are called ACR battery links. Pretty cool.
Understood on the ACR. You are missing my point about the dc/dc charger. I dont know what you are driving but your alternator is not typically capable of charging a second battery to full. That's where the dc/dc charger comes in. It can charge up to 15.3v most alternators will not go that high. It steps up your alternator output to properly and completely charge your secondary AGM battery. This will dramatically increase the life of your secondary battery. It can replace your ACR and solar controller as well.
 
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Understood on the ACR. You are missing my point about the dc/dc charger. I dont know what you are driving but your alternator is not typically capable of charging a second battery to full. That's where the dc/dc charger comes in. It can charge up to 15.3v most alternators will not go that high. It steps up your alternator output to properly and completely charge your secondary AGM battery. This will dramatically increase the life of your secondary battery. It can replace your ACR and solar controller as well.
The dc/dc is what I’d like to get next. The Renogy version is $199 for the 20v version. They also have a 40v version. But this would solve my gap when the weather is not clear and the solar is not charging/can’t charge.
 

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The dc/dc is what I’d like to get next. The Renogy version is $199 for the 20v version. They also have a 40v version. But this would solve my gap when the weather is not clear and the solar is not charging/can’t charge.
I saw those. I find it interesting that coming from Renogy they do not have a solar controller built in. At least I can not find any info that says they do. That's why I'm leaning towards the Redarc. One unit to charge while on the move and the same unit will automatically switch to solar when I arrive at camp and plug my panels in. Clean and simple solution for me.
 

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I saw those. I find it interesting that coming from Renogy they do not have a solar controller built in. At least I can not find any info that says they do. That's why I'm leaning towards the Redarc. One unit to charge while on the move and the same unit will automatically switch to solar when I arrive at camp and plug my panels in. Clean and simple solution for me.
Exactly! I just have to watch enough YouTube videos to give me the courage to actually install it myself lol.
 

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Exactly! I just have to watch enough YouTube videos to give me the courage to actually install it myself lol.
The nice thing about the dc/dc setup with a solar controller built in is it's a very minimal wiring setup. Or so I keep telling myself...I do not own one as of yet. I could have but I bought a ARB twin compressor instead. Oh well all in due time.