Inverter replacement 2000W or 3000W?

[Sailfast]

Replacing the existing 1000W Magnum with a 2000W or 3000W inverter, that’s the question.

Fact: The AI’s 120VAC power is limited to 30A main service, even though the combined load of all appliances is way more than that. However, there is such a device called a Power Control System (PCS) I/O Module. As appliances such as Microwave, Coffee Pot Hair Dryer, AC are turned on, the PSC will constantly monitor 120VAC power and shed/restore power to the controlled loads.

I.e. whether it’s a 2K or 3K Watt inverter with 30A transfer switch, installed such as to control the entire AC panel (between 30A main and shore/gen power transfer switch), as long as you are on shore power or generator, size won’t matter. The minute you switch to inverted power, then size will matter.

Dilemma: available space. For instance a Xantrex x2000 will mount just about in the same space the Magnum is now. So minimal rewiring, time and labor. A 3000W unit not so.

My thinking: Running an air conditioning unit off an inverter in the AI is not realistic because of the considerable size and costly battery system needed for effective use. Any other appliance, including the 1500W microwave will be able to operate on a 2000W (high quality) inverter. So it is just a matter of managing your loads for the very short time you may need it.

When I venture into public camping venues, I always ask for spacious sites, no water no electricity (those spaces are often tight, one large unit after another). I like my Espresso and I always introduce myself to the neighbors and ask them whether it’s OK to run the generator for 30 minutes in the morning. Yes, it’s always OK with the verbal reply, not always with the looks in the eyes.

So I guess it’s a good thing to keep noise levels to a minimum. For that (and my coffee) I am willing to spend a few dollars, at the same time make the right choices.

Your thoughts and opinions are appreciated.

[Rocinante]

First off, your rig, your money, but it sounds like you're on the right track. If you don't have any interest in running the AC on the inverter, a hybrid replacement for the Magnum, rated at 2kW, should be enough to allow you to run the microwave or a reasonable electric appliance (e.g. coffeemaker). As long as you have enough battery power, which may or may not be a good assumption, you may be good to go. In the battery department you'll be happier with at least a pair of LiFePO4 batteries (e.g. 200AH), because Interstates are notoriously under-powered in the coach battery department when it comes to dry camping.

[toskeysam]

When we were planning our lithium upgrade, we decided we wanted to be able to run the AC of batteries, for short times. That being rest area stops or knocking the day’s heat out of the coach. That being said we had Lew install the 3000 watt hybrid Magnum inverter. We coupled that with 3 -160 ahr Victron batteries.
I have learned, over the last few years, that I could’ve gotten by with 2 batteries. When I decided on 3, I felt like...”in for a penny, in for a pound”....the work wasn’t much more to go for 3.
I also installed the Microair EasyStart on the AC. It took the inrush current down for the compressor start and stopped slamming the inverter with that load.
The only load that is not carried by the inverter is the water heater. That’s because we can use propane for that application.

[Hawk-ination]

Sailfast, just curious if you know the Xantrex will fit for sure or not? I started to study the area last week and came to the conclusion to try to put any other inverter in the area where the Magnum is, there are wires running on the floor the length of the box. Not sure I will be able to make anything else work well without building a shelf and even then, I'll have to watch the measurements. That is if your inverter is under your sofa like ours, and you have the same issue with the wires running along the floor.

There's other members who have replaced their inverters so maybe someone else can help explain what works and what didn't for them better than me. I am hoping to find another option as I'd like not to take up the valuable storage space behind the sofa. The Victron just seems to take up too much room to be an option so hoping to go with a different answer. I have another inverter to install but it's also a little bigger than I'd like, so looking for an alternative also.

[Rocinante]

For our configuration we gave up under-rear-lounge storage on the passenger side. They put the pair of 200Ah batteries and the 3kW inverter under there. OTOH, they managed to save all the rest of the under-sofa storage, so we felt like it was a reasonable trade-off. Still, I do understand the reluctance to give up that storage space.

[Hawk-ination]

Rocinante, what inverter do you have? Think you’ve said before but I don’t remember.

Absolutely no offense to anyone who has installed in the back storage area, or installed a Victron. We just take so much extra stuff for our hobbies and such. I mean no insults to anyone on your decision on inverter placement or selection. We’d probably benefit from a little bigger RV but the trade-offs work for us. If there was only a box and bike rack combo that was the size of a small apartment, life would be good!

[Rocinante]

No offense offered or taken. My philosophy is always, "your rig, your money, do what seems best for you."

We have the Victron 3kW hybrid inverter / charger and a pair of 200Ah Life Blue batteries back there. In the space under the jump seat where the old unit used to be, we have a Victron solar controller, and a Victron Cyrix battery isolator/combiner.

[Sailfast]

Originally Posted by Hawk-ination

Sailfast, just curious if you know the Xantrex will fit for sure or not? I started to study the area last week and came to the conclusion to try to put any other inverter in the area where the Magnum is, there are wires running on the floor the length of the box. Not sure I will be able to make anything else work well without building a shelf and even then, I'll have to watch the measurements. That is if your inverter is under your sofa like ours, and you have the same issue with the wires running along the floor.

There's other members who have replaced their inverters so maybe someone else can help explain what works and what didn't for them better than me. I am hoping to find another option as I'd like not to take up the valuable storage space behind the sofa. The Victron just seems to take up too much room to be an option so hoping to go with a different answer. I have another inverter to install but it's also a little bigger than I'd like, so looking for an alternative also.

...actually a Magnum CSW2012-HX will fit in place of the MM1012 with minimal effort to connect the AC-in and AC-out wiring from the existing Magnum. The CSW2012 AC-in is the wire that presently goes to the 30A Main Breaker, a replacement #10/2 w gr will go from the AC-out to the 30A Main.

This is just an inverter with transfer switch, for charging we'll use a dedicated 60A CC/CV charger for the 220AH LiFePo4 bank. That charger will have to be mounted on the "outside" of the same panel the inverter is on (inside). This requires minimal wiring; DC #4 cable to CSW2012, AC can be plugged into the CSW2012 directly.

A 80% LFP charging routine (between 18% and 98% SOC) is electronically controlled and cannot occur during inverter operation. Material cost for the above is under $500

[Hawk-ination]

Minimal effort would be great. Good info on the Magnum.

We have two different end goals though, my goal is to run the AC for a few hours in the end. I think you will find your inverter to fit and I really wish I could also. I’ll probably end up going with a suggestion to put the Victron behind our Battle Born bank on the right side and leave the 64” stretch to take the screen tent and bed foam piece at times. Good discussion on what works best. Hope a couple others chime in as it’s still good to hear what options have worked for others. Best of luck!

[Sailfast]

Originally Posted by Hawk-ination

Minimal effort would be great. Good info on the Magnum.

We have two different end goals though, my goal is to run the AC for a few hours in the end. .........

Well, playing the devils advocate here; ......running the AC for "a few hours" off-grid requires expensive and space consuming equipment and changes of questionable benefit or comfort. AC will be pulling >100A off your LFP bank, so a 600AH of supply will hardy give you full "comfort" in a 12 hour period, let alone a 24 hours. A solar system on an AI to recharge 600AH or even half of that is unrealistic. You are off-grid and what you will have to do is operate your generator or go for a (depending on alternator) long drive to replenish your battery bank.

So if you're camping in hot weather and desire AC comfort, it makes sense to seek facilities with shore power. If you are off-grid and it's that bad, turn on your generator for a few hours. If the noise bothers you too much, purchase a Honda 2000 and a soft-start for the AC, you won't even hear the Honda over the noise of the AC.

Yes, I know there are several Class B products out there with LFP systems to operate AC's. Any of those products no longer have generators, rather large, powerful alternators. However, I have yet to hear how great it is to go off-grid for a few days in Death Valley, in a Class B camper van with the style and comforts of home.

Not trying to dissuade you from your project, just stimulating the thought process.

[Rocinante]

In these discussions it is always useful to remember that the wheels are also an important part of the climate control equipment in any RV. [emoji106]

[Hawk-ination]

It natural to think our particular situation is similar to what someone else is getting at, but sometimes situations might be different in what works for others at times. I do realize it will cost some to upgrade and I expect we will only be able to run our AC for a couple hours. Don’t have expectations to boon dock for days and run the AC unit with upgrading the inverter and the solar. I also do not have expectations that the solar will fully charge the lithium batteries.

We use our RV for travel with two dogs. When we want to go have lunch or supper with our family, or just lunch in general, we have to fire up the generator to run the AC unit. We simply want the freedom to take our pups with us, along with keeping them comfortable. I’ve had times where I’d use it to sit at sports practices and such, where a couple hours of quiet AC would have been fantastic. We live in the Midwest where some days in the summer are so humid and hot it is almost unbearable.

I do appreciate your two cents though as it would be expensive and a shock if I didn’t realize that an expensive inverter upgrade along with a couple more Battle Borns and solar would allow us to stay off grid.

We’ve also been through some pretty nasty situations like Texas this week, where survival was a very big challenge. After experiencing those events, it doesn’t bother me to spend some to upgrade the Interstate. It got us through a terrible week of no water and electricity after the derecho last year. When you go through things like that, the monetary amount takes a back seat to things a bit.

[3OnOurWay]

Hello Sailfast and Hawkination and others who kept inverter upgrade to the OEM front passenger seat location

Could you provide an update / pics/ unforeseen challenges to the install? . Thank you for the help.

I am starting to explore this upgrade now since we have a bit of downtime to fine tune this. My goal is ‘microwave start of day / end of day and we primarily boondock. Not to interested in AC though will be installing soft start.

I also saw that the new Epoch battery 120ah could fit as upgrade to original OEM Undercarriage location and provide 20% capacity for under $1500 total with increased surge / duration and still provide CCA start ability to generator.
Thanks for weighing in. I appreciate the help I always find here

[Chopperguy]

Hi there, I was wondering if you ever tried to install those new group 24 batteries under the coach in the spot of the original 4 agm batteries? Wondering if they indeed fit.

[3OnOurWay]

Hi, if that question is for us,

we were one of the first AI24GL changeovers to factory OEM lithium undercoach. We have two "boxes" behind the roadside and curbside front tires. Each box fits just the BB 100AH battery. Currently, I think an easy swap same size, is the EPOCH 120AH battery, it's a CCA battery $699 priced each for a total of 40 more AH. In our usage 40Ah is 12-20 hrs of extra use. I don't see us upgrading batteries for a few more years, we still have, by my measurements 96% of our original battery usage.

Though if I could dream, for $300 more each, $999, it would be amazing to retrofit a 300ah battery on either side!