Teardrops n Tiny Travel Trailers

my first post dissappeared, weird.

Sounds like i need a ANL fuse between the 2000w inverter and the 155ah battery. The booklet says that it needs to be on the positive side between the inverter and battery. Found a rough guide online and it recommended about a 350amp fuse. Does this sound right?

it will be on a 4awg wire, fairly close <12" from inverter to battery

Maybe 30 amp fuse? I don't think I've ever seen ANY fuse at 350amp. That would cook most any wiring I know of. The main breaker to most houses is only 100 amp or less. It would be a BIG one! Remember, the purpose of fuses and breakers is to protect the wiring, not the appliance. The fuse limits the amount of current to the amount the wiring can safely handle. Too much current (amps) means red hot wires, and then smoke, and then fire. All bad things...just sayin'

McDave

On the other hand,
https://www.bluesea.com/products/5120/C ... _-_350_Amp



Here's a chart, I love charts,...
http://www.cerrowire.com/ampacity-charts

Well, the fuse ought to allow the biggest power load you actually expect to use, and the wires should be sized to carry that many amps.
2,000 watts = 12 volts x 167 amps. Even more when you consider the efficiency of the inverter.

In our builds we have 2,000 watt inverters but we don't ever really expect to pull all 2,000 watts from the batteries.
We have over-sized the inverter/charger to reduce stress and increase life.

We will use a 100 amp ANL fuse on the tow vehicle, placed 3 inches downstream of the tow vehicle battery on the positive leg.
That will allow 1,000 watts to run the air conditioner from the tow vehicle but still protect the long power wires, the car battery, and the car alternator.
For the trailer battery we'll use a 150 amp DC circuit breaker like this one.
The boat guys have them at the marine supply websites.

http://www.bestboatwire.com/circuit-bre ... nt-150-amp


That will protect the trailer battery and that short run of wire.
I prefer a breaker there because I expect me or the wife will forget we are boondocking and turn on too much 120VAC load, like the microwave and coffee maker together. I would rather reset a breaker than change a fuse. But I don't want to limit the 120VAC circuits so when we have shore power we can use everything.
For the tow vehicle power line the fuse is OK, it should really be a fault or failure (short) that puts 100 amps on that line.

Keep in mind that a fuse is really a temperature sensor - it melts when the current makes it too hot.
So if you camp in the desert or mount it in the hot engine compartment, you won't get full rated power through that fuse.

2000 W @ 12VDC is 167A. If you expect to actually draw that 2000W from your inverter you need a 150A fuse, but your 155AH battery will be DEAD FLAT in less than an hour at that rate.

Your 155 AH battery will provide ~75AH before reaching 50% charge level. Discharging a Lead-Acid battery below 50% drastically shortens the life of the battery.

If your loads really add up to 2000W you need a generator like a Honda EU2000 not a 155AH battery.

<Chas>

GuitarPhotog wrote:2000 W @ 12VDC is 167A. If you expect to actually draw that 2000W from your inverter you need a 150A fuse, but your 155AH battery will be DEAD FLAT in less than an hour at that rate.

Your 155 AH battery will provide ~75AH before reaching 50% charge level. Discharging a Lead-Acid battery below 50% drastically shortens the life of the battery.

If your loads really add up to 2000W you need a generator like a Honda EU2000 not a 155AH battery.

<Chas>

For our setup we allow big power from the inverter knowing it's only good for a few minutes.

My coffee maker runs for 15 minutes. My microwave runs 4 minutes for the wife's tea or to heat up a plate.
We can make that work. The tow vehicle is right there to recharge the battery if we want to let it stand and run for an hour or so.
That's OK for me every day or two in the boondocks.

Aguyfromohio wrote:

GuitarPhotog wrote:2000 W @ 12VDC is 167A. If you expect to actually draw that 2000W from your inverter you need a 150A fuse, but your 155AH battery will be DEAD FLAT in less than an hour at that rate.

Your 155 AH battery will provide ~75AH before reaching 50% charge level. Discharging a Lead-Acid battery below 50% drastically shortens the life of the battery.

If your loads really add up to 2000W you need a generator like a Honda EU2000 not a 155AH battery.

<Chas>

For our setup we allow big power from the inverter knowing it's only good for a few minutes.

My coffee maker runs for 15 minutes. My microwave runs 4 minutes for the wife's tea or to heat up a plate.
We can make that work. The tow vehicle is right there to recharge the battery if we want to let it stand and run for an hour or so.
That's OK for me every day or two in the boondocks.

If you are going to use the tow vehicle to charge your battery after big draws like this, the cables to the TV battery need to be #4 or larger also. Unless you want to run the vehicle for hours to replace a few minutes usage. What comes out must go back in.

<Chas>

OK, I just learned something. It didn't hurt as bad as I thought it would. Thank you Aguyfromohio and GuitarPhotog. I hadn't considered running the trailer AC from inverted 12v off the TV alternator while in flight. I do have the trailer battery charging and 12v fridge powered from TV. Soooooo, a pre cooled trailer ya say? I believe I have a 185amp alternator, that should be able to support that kind of load, yes? Well now,....if I can do it, I probably should do it,... just sayin'..

Thanks again guys, gotta run.
I've... got... a plan....


McDave

Exactly true, GP.
We sized that wiring for a different load, running the trailer air conditioner from the tow vehicle.
We are using two #4 wires each leg, four wires total.
That gives 0.37 volts drop at 100 amps. We actually expect only 70 amps for running the air conditioner, it's nice to have a cushion built in.

Aims recommends a 500amp fuse for my unit. 3000w continuous 9000w peak. Don't forget modern inverters can peak 2 to 3 times thier continuous rate. Installation pdf recommends 00awg from battery to inverter and less than 6 feet in length. The origonal poster I believe is inquiring about the model below mine. 2000w/ 6000w peak. I recommend 250 fuse no less than 0awg of 4 ft.