Inverter/Charger in lieu of EMS? Combo units vs. separate components?

[yendor]

I'm preparing to receive our first RV next month (a Winnebago Micro Minnie 2100BH), and planning for electrical system upgrades to provide us with more flexibility for a variety of on/off-grid travel.

I've read that an EMS (electrical management system) is useful to protect the RV's electrical components, as the electrical hookups for RVs can be somewhat unpredictable (undervoltage, overvoltage, etc). However, it also sounds like the more advanced inverter/charger units (like the Victron MultiPlus) might also provide the same protection, with further benefit of supplementing grid power with power from the batteries (when shore power dips), and charging the batteries when more power is available from the grid. Is that an accurate interpretation? Can I safely forgo an EMS with a system like this?

Also, I see an advantage to systems that integrate the inverter/charger/MPPT functionality in one box, as more of the switching between modes can be done automatically...but I also worry that when one function fails, you're left with a very expensive brick. How worried should I be about partial failure? Or is it practical to get the same functionality with by connecting separate independent (inverter/charger/MPPT) components?

 

[Jeffjeeptj]

My recommendation is to get the EMS, no matter what solar or inverter you add. I have a Multiplus that I am using for a “portable” system. It may wind up in my Travel Trailer in the future. My experience with campgrounds is their power can be iffy. Wife and I full timed for a number of years, and what we found at campgrounds was sometimes incredible. The multiplus acts as a very nice transfer switch and a “booster” when RV draw exceeds available shore power amps. If installing this into my tt, I would put the EMS between shore power and the multi.
Look at youtube and “all about rvs”, “love your rv”. There are many others, too. IRV2 is a good forum.
RVing is great fun. Do not go crazy on ‘accessories” until you use the unit 15 to 30 nights. What you must have will become apparent Based on your use. If always at a campground with power, no solar should be needed. If never near shore power, solar will be needed much sooner, and you’ll get good at water conservation.
HTH

 

[Jeffjeeptj]

One thing about the Multi, When it was initially programmed (and it is very flexible), it utilized “shore” power very nicely and was very quiet when it charged my lithium batteries. It was bought in late 2019. It would not recognize my 2004 vintage Honda eu2000i generators. Programming had to be changed (a well known situation, readily documented on the victron community, and easy). Now, it uses shore and genny power to pass thru or charge the batts, but, when charging it has a fairly loud hum. I could program it to not recognize the genny and it would charge quietly, like it did initially. That requires me to boot up an infrequently used Windows 7 based laptop to use the Victron software. I really do not want to lug around a laptop when I am happy to use an ipad, that just will not program the multi.

 

[yendor]

Thanks for the advice--based on your suggestion, I've brought back the EMS on the top of my accessories list for now, planning on a Progressive Industries HW30C, unless I hear recommendations otherwise.

In terms of other electrical accessories, I've picked up a pair of Lion Safari UT1300 batteries since they were on sale at Costco, and negotiated a $140 accessories credit from my RV dealer in exchange for the battery they were going to provide. My understanding is that I can use these as a drop-in replacement for the standard SLA, but I won't realize the benefit of charging them as full or fast as possible; nevertheless, charging them slowly and below their peak capacity shouldn't harm their longevity, and might even be less wearing on them.

I also ordered a single 100w solar panel and matching charge controller from Costco, primarily so I can do some early experimentation with solar charging before I do anything big (knowing that I can return it to Costco if I decide it's not right for me).

Beyond that, I already have a 1100w modified sine wave inverter that I purchased a few years ago as a basic backup power source at home (intending to connect it to the battery of my Nissan Leaf), and could bring it into the RV for limited AC use off-grid until I have a need for something more.

 

[Jeffjeeptj]

the HW30C is a nice unit. I have friends with that one. I use the plug into the pedestal unit. I have read that the HW30C does not like the power from an inverter generator since the neutral and ground are not bonded. There are videos about this and the solution, if you may be using a generator. A “bonding” plug solved the issue for me. I use that plug when I am using the genny to power the multiplus.

one other item that is of great benefit is a “coulomb counter” battery monitor. Something like a Victron bmv-712 or similar. Their recently released smart shunt looks like a bmv-712 without the display. Bluetooth works well, in fact i have the display buried.

there is a lot of good info on this forum and Will’s videos.