2000 or 2800 watt inverter?

[MaryL.]

Hi everyone,

I'm looking for some advice on whether to use a 2000 or 2800 watt inverter. We're planning to have a dealer install (2) 160 watt GoPower solar panels on the roof. For the solar installation, the dealer is quoting a total of $2100 which includes all parts and labor (panels, controller) At the same time, we're looking to have the dealer install an inverter. We expect to use the inverter for watching TV and occasionally using the microwave. The dealer is saying we should get an inverter charger with the automatic transfer switch and go with the 2800, bigger is better. If we go with the 2800 (looking at the Magnum), does the wiring have to be changed to a heavier gauge wire? I don't want to do more wiring changes than necessary, is the 2800 overkill?

Thanks much!
Mary

[TucsonJim]

According to the Magnum installation guide, wiring size will be dependent on the length of the run from the battery to the inverter. If your run is five feet or less and is in free air, the wiring for the 2012 (2000 watt 12V) is 2/0. For the 2812 (2800 watt 12V), the recommended wiring is 4/0. If the run is in conduit, the only change is to change to 4/0 on the 2012.

If your run is longer than five feet but less than 10, you need to ramp up the wiring based on Magnum's chart. For the 2012, you need to go to with 4/0. For the 2812, you need to run double 4/0 runs.

For 10-15 feet, the 2012 needs two runs of 4/0, and it is not recommended for the 2812.

In the grand scheme of things, the wiring will be a very small portion of the total price. In fact, I'd recommend you go one wire size larger than the recommendation just to assure that you will not have significant loss.

What kind of a battery bank will you be running to power the inverter?

Jim

[kregli]

Mary,

I think Jim covered the wiring well. I suggest you think about the size of all components in the system together. Using the microwave forces a pretty large inverter - something over 1500 watts. Using the microwave will draw around 120 amps from the battery, so if you use it for 15 minutes it will consume about 30 amp hours. The TV will be on the order of 100 watts drawing around 10 amps, so if you use it for 4 hours that will be about 40 amp hours. Given fridge fans, furnace fans, lights, and other stuff your probably talking 100 amp hours out of the batteries in a day. The battery that probably comes with your trailer is a 100 amp hour battery (wet cell) which means you won't be able to use more than 50 amp hours before recharging. So you probably need more battery power. The 320 watts worth of solar panels will typically produce around 80-100 amp hours on a sunny summer day, which would recharge the standard battery, but you'd need more if you increase your battery power. Those are very rough calculations, but hopefully it will give you some ideas. Many solar sites have extensive help in figuring this stuff out.

[MaryL.]

Jim,

Thank you for the information! As the trailer is new, we only have the (2) 12 volt batteries that the dealer provided as part of the purchase price of the trailer.
I imagine I will need to change the batteries at some point to (4) 6 volts, maybe AGM's, but I'm thinking it would be nice to get some use out of the current batteries.
I heard back from the dealer and he says he can get the MS2812 and the remote panel for $1990 total. I'll have to check Amazon to see if that's a good price.
I'm not sure how much dry camping we'll do, likely 20% of the time. We're not full timers so that's why we're going with only 320 watts of solar power for now. I'm sure that much solar will change the existing batteries pretty fast, and it's probably a little overkill on the solar with the existing batteries........

[MaryL.]

Keith,

Thanks so much! I really appreciate your response. I'm a little lost on the inverter size differences and how much wattage I'll really need. I read a post and think I'm beginning to understand it, then I read another post and think it's a better plan than the other one........what to do, what to do. It seems for the price difference between the 2000 and 2800 watt inverter, the 2800 is a better buy as it's just a little more expensive and if we do want to dry camp more in the future and use more convenience items, then we'll have enough wattage. I just want to be able to watch a few hours of TV and keep the house batteries charged while we're dry camping, maybe run the microwave for 5 minutes at most, and maybe run a hair dryer for 5 minutes.

Mary

[TucsonJim]

Mary - Personally, I'd go with the 2812. Your dealer is a little higher than Amazon, but less than what Magnum charges. That is a nice solar set up and you probably won't have to expand it anytime in the future. As you already know, your battery bank is the weak link. Just don't let them get too low watching TV so you can't run your furnace over night if needed.

I have a 2000W inverter, 300 watts of solar and three 12V batteries for a total of 270 amp hours. I try to keep microwave use to daytime so that the batteries will have time to charge back up before the sun goes down. My batteries do a good job of providing power for a drip coffee pot in the morning, and watching TV at night while also powering a Winegard satellite dish and VIP211Z receiver.

Jim

[MaryL.]

After doing more looking around on Amazon, what do you guys think about this system from GoPower? $2703.99 for the Go Power Elite Coplete Solar Kit & Inverter System.
It looks like it has everything I need. Granted, the inverter is 2000 watts but I think that would be OK for what we need. I don't have to use the hairdryer or the microwave....

https://www.amazon.com/Go-Power-Sola...Y2DCM3K2AYJ8MG

[TucsonJim]

My microwave runs just fine on 2000 watts.

Jim

[MaryL.]

Yay, I can heat up a burrito!
Do you think the GoPower complete system is an OK deal? It says it also allows for the expansion of one additional panel that can be added within the existing controller capability.

[Rodney Stokes]

I have a 2000 watt pure sinus inverter. I can run 2, 4 or 6, 6 volt batteries. I have no problem running the TV for hours. Running a fan or two all night. Then the wife fixes coffee and does her hair. After all that, 2 batteries are about 1/2 way down. If we do some real dry camping then we cut back a lot. And the new TVs these days are real low power draws. There should be minimal power draw while watching them. Also, I cheat. I have a 36 volt golf cart. Borrow the batteries, use them, charge and put them back in. Less money dished out.