Hooking up a 400w inverter

[LandC72]

Is there a location where I can hook up/connect a 400w inverter in my A122s on the inside of the trailer to charge a laptop or cell phone when operating in the boondocks on battery only. Thanks, Larry

[loki008]

I would recommend adding a 12v plug and use that. Being that both of the devices you listed are DC you will actually be better off using a 12v charger as an inverter is not 100% efficient and you will actually lose battery life as you are basically going from DC to AC and back to DC.

As for where you can add a 12v plug, I chose to add mine under the radio. If you remove your microwave there seems to be a good 12v line there (I didn't trace it, but it seems to be on its own fuse) that goes to the radio and night light.





You can see here that I added dual charging ports ((2) USB and a 12v plug) as well as a volt meter so i know the charge of the battery.

[Herk7769]

IMO, put the inverter as close as possible to the battery (direct connect with an on/off switch) and run an extension cord to your charging area.

400 watts at 12 volts is 34 amps draw from the battery.

If the distance from the battery to the inverter terminals is 10 feet or less you can use #8 red/black wire (3% voltage loss) but bigger is better - less loss for the same length.

I would use #6 wire for the least voltage drop at 35 amps.

Since 400 watts at 120 volts AC is only 3 amps AC or so, any size extension cord will work fine.

[Evereddie]

While there is an abundance of 12 volt to cell phone chargers, there is very little in the way of 12 volt charging systems for laptops. Most take 16 volts and up. You will need an inverter for this using the laptops charger..

While Herk is absolutely correct in his wire sizes and theory, you may not need to go so far if you are ONLY wanting to charge a laptop. Laptops take no more than 100 watts and thus you will not need as big a wire as opposed to setting up the inverter for 400 watts. Although once set up you may find other bigger items that you may want to plug into the inverter than a laptop so wiring it for the maximum power output is the way to go.

[ko777]

I use a power pack instead of the TT battery.

I got over 6 hours of entertainment on a 29" HD TV, media player with a 500GB portable hard drive attached and occasionally use my laptop.

But I plan to put a lighter plug extension to the wiring of the tiny light under the microwave oven. I will only use this to recharge small devices and check the voltage of the TT battery.

In my 2012 A128S, it has this option. I took off the light because I think this is in a bad location of being hit, I somehow hit the light cover and broke it, so now I have an option to replace this with a lighter plug panel; (Loki) Please post the link of where you got the power panel. I would like to put that there.

[Herk7769]

400 watts is actually a perfect size

My 32 inch LED TV is 80 watts
My Laptop HP power supply is 120 watts
iPad Charger - 10 watts
iPhone Charger - 4 watts each x 2
MS Surface Power Supply 24 watts
Blu-Ray DVD player - 14 watts

You can run all this and a few other DC items (like water pump use and some lights, minimal or no heat) without over taxing a 100 - 150 AH battery set up.

You will need some way of replacing that power the next day, generator or solar.

[loki008]

Originally Posted by Evereddie

While there is an abundance of 12 volt to cell phone chargers, there is very little in the way of 12 volt charging systems for laptops. Most take 16 volts and up. You will need an inverter for this using the laptops charger..

While Herk is absolutely correct in his wire sizes and theory, you may not need to go so far if you are ONLY wanting to charge a laptop. Laptops take no more than 100 watts and thus you will not need as big a wire as opposed to setting up the inverter for 400 watts. Although once set up you may find other bigger items that you may want to plug into the inverter than a laptop so wiring it for the maximum power output is the way to go.

I disagree. From my experience there is a DC adapter for every laptop out there. They aren't popular and they don't come with the laptops but they are readily available. Amazon, Radio Shack and just about all the laptop manufacturers offer them as an option if you order the laptop directly from them on the customization page. I know this because we have quite a few teleworkers at work that travel quite a bit and we keep universal 12v chargers in the office where you just swap out the tips for the different laptops. in addition my ThinkPad was ordered with the optional travel charger which replaces the standard charger and comes with 2 cords that plug into the charging cable. one AC and one DC.

Higher than 12v doesn't matter. it's still more efficient to convert the voltage than invert from DC to AC then back to DC. Your battery will last longer without the loss of the dual conversion.

[loki008]

I'll post it later this morning. I ordered it from Amazon. there are smaller ones than that one as well. I liked this one because it had the dual USB and looked more like something that would come from the factory.

[Herk7769]

Originally Posted by loki008

I'll post it later this morning. I ordered it from Amazon. there are smaller ones than that one as well. I liked this one because it had the dual USB and looked more like something that would come from the factory.

That IS pretty cool. I may need to buy one!

[loki008]

As promised.

Here is the link to the dual port plug that i got from amazon. Its a bit more expensive than I would like ($45), but to me it was worth it for the finished look.

Here is just a 12v plug for $10

and Here is a dual USB charger for $20

so for $10 less you can just buy both of those and get the same exact functionality. But to me the $10 was worth the cleaner looking mounting frame.

[ko777]

I wish they have the same price in Amazon.ca cost $25 for the lighter plug, thanks for the links.

[Pooneil]

I agree with other posters that the inverter should be avoided when boondocking in favor of direct 12 volt options.

I used an inverter on a previous camper to run a CPAP and to power a florescent light. Developments in CPAP and lighting technologies have eliminated the need for the inverter. Another problem with inverters, it the need to place them close to the battery then wire a plug inside the living area. If you are gloing to that trouble, then you might as well ust run a new 12 volt wire and put in a few outlets.

Here is the latest model of the laptop charger I use.

Targus Laptop AC/DC Travel Charger with USB Fast Charging Port & USB Charging Dongle | Targus Tablet, Smartphone, and Laptop Cases | Targus

[jwedell]

I installed a few hd 12 volts outlets (used #10 wire) Most of our items are 12 volts. The tv and sat box were 120 volts. When we boon dock we use a small plug in inverter and plug the tv and sat box into it. Works great for us. Dw uses a 12 volt cpap so no problem.

[loki008]

Originally Posted by jwedell

I installed a few hd 12 volts outlets (used #10 wire) Most of our items are 12 volts. The tv and sat box were 120 volts. When we boon dock we use a small plug in inverter and plug the tv and sat box into it. Works great for us. Dw uses a 12 volt cpap so no problem.

Best Buy has a few decent TV's that run off of 12v (they come with laptop style AC plugs that output 12v). I picked up at 24" model with built in DVD player as seen in my previous pictures for $130 recently and then picked up an adapter plug for $20 at radio shack (probably could have gotten it cheaper online if i knew the plug size).

Also if you use DirectTV (Im sure Dish as well does, a lot of the mini set top boxes don't have room for AC to DC transformers internally and take straight DC and put the transformer in the wall plug) I know that a few of their smaller boxes are 12v as well and use the same laptop style plug. So if you ever wanted to you could swap that out for 12v as well.

Here is where i am going to completely derail the conversation. I apologize to the OP; Please disregard as its not specifically relevant to the question. Just figured I would add some math and back ground info to why using 12v is much better when running from a battery

Due to the nature of electronics basically if its not a compressor or motor it runs on DC. The reason that we use AC in our houses is due to the fact that long range transmission of DC power has some technical limitations. its much more efficient to use DC especially with the efficiency losses with AC to DC conversion (most inverters / transformers are around 80-85% efficient if i recall correctly off the top of my head with the lost energy going to heat, this is why they are warm to the touch).

So if you are using an DC to AC inverter you are using 125% of the power required to charger your Laptop due to the power loss of the inverter. Then if you are using a AC to DC transformer to charge your laptop you are now using 156% of the required power to charge your laptop due to the secondary loss introduced by the second conversion.

Here are some examples. PC power supplies are some of the few transformers that publish their efficency ratings. HERE is an example of an energy star rated power supply and it is rated as "80 PLUS Certified, with up to 80% efficiency under typical loads".

HERE is a 400 watt inverter that publishes its efficiency rating. "Efficiency (full load, 12V): > 83%"

[LandC72]

Thanks for all of the replies. I especially like the battery meter. Larry

[1A Camper]

If you do need 400 watts and I do. My lap top draws 180 watts, needless to say I do not run it a lot on TT battery. I normally charge it in the TV when we are moving.
I added a direct wire from the battery to the seat front next to the front wall using a 12V plug. Not the easiest place to get too but the shortest wire run.

[loki008]

Originally Posted by LandC72

Thanks for all of the replies. I especially like the battery meter. Larry

Here is the battery meter link. It is out of stock right now, but im sure it will be back soon. I think i paid $17 for it. There are a few others, but i liked that this one had the trim piece included and that it gave me the voltage, not a "gauge" so i specifically know what the battery is at.

[rawlus]

a 400w inverter seems extreme overkill to charge a cell phone. the avg cellphone needs a 4w on DC to charge.

a laptop i would not recommend charging from the trailers battery bank - they're usually 40-75w to charge depending on make/model.

you can charge a cellphone on a very small solar panel or even a hand crank charger or carry one of the many backup battery systems. if you're off the grid then presumably the cell phone needs are infrequent right? haha.

laptops i think i would look at replacing with an ipad or something that has far longer battery life and smaller recharging needs - 5w or 12w (fast charge)

[Teamvandy]

Thanks for the info loki008, I did this exact same thing based on your post. I'm going to hook up the dual USB into the switched line with the night light (because of the always on light on the USB port) and hook up the 12v plug off the radio. I was a little dismayed when I cut the hole in the cabinet using the template because I thought it was too wide to support the screws that attatch the base to the cabinet until I realized the top and bottom tabs come off allowing access.

[Gerry O]

Ok, this is my first post on this forum as I'm a new member.

Just bought a T12RB and still learning about it. My previous camper was a Sprinter van that had two 6v batteries which ran a 1750w inverter. This was enough power to run the microwave.

Has anyone installed a similar type of inverter in a aframe?

Thanks