If you're thinking of adding an inverter or inverter/charger to a solar / battery system, then you obviously want to run some 120vac stuff off batteries when there's no other power. If you've only added solar to extend battery power for off-grid camping 2-3 days at a time, then you probably don't need an inverter / charger. Just get a plain inverter to run your elec stuff for a few days and plug in a battery charger when you get home, or plug in at a campground and let your factory RV converter* trickle charge your batteries. If you're looking at extended or full time solar power with 120vac, then an inverter / charger makes a lot of sense
* An RV converter is not an inverter. It's the opposite and works only as a weak 12v trickle charger when you're on grid power
What's the difference from just a regular inverter?
An Inverter connects to a 12v (or 24-48v) battery bank and turns that 12v DC power into regular 120v AC household current. From a "pure sine" inverter the electricity is exactly like from the grid power company.
An Inverter / Charger does the same thing, but it also functions as a powerful and sophisticated battery charger when shore power is available, or when it senses a generator.
What are some Advantages to having that extra charging function?
1. If you're off the grid with solar and batteries, there are times when your usage can outstrip what's coming in from the solar panels, like after extended periods of heavy clouds, stormy weather and little sun.
Sometimes the only alternative is a gas generator, but they're loud and expensive to run. If you can run a generator for a short time and quickly recharge your batteries while you're using gen power, then the run time can be minimal. I've seen folks plugging an automotive type 12v charger from wally world into a gas generator to recharge their batteries and I cringe. It's not efficient to say the least, and will take a LONG time to get deep cycle batteries charged. Those car battery chargers typically put out only 5-10 amps, and there's no charging algorithm like with a solar charge controller. A Magnum 2000W inv / charger for example is a 100 amp charger, and also has 5 stage charging, Bulk, Absorb, Float, and Equalize (and battery saver)
* A hybrid system combining a generator with an inverter charger can be very effective and increase the gas mileage on your generator by 300%. If you have solar panels, tests have shown it can be as much as 1000%
2. They are easy to install and charge automatically when sensing shore power
With 2 lugs for the pos / neg connection, they simply get wired directly to your breaker box pos / neg where shore power comes in. When Shore power is disconnected, an Inverter supplies all the AC power. Whenever outside power is connected, either the grid or a generator, the inverter has an automatic sensor transfer switch to stop supplying 120 and start charging the batteries. There's no conflict with the solar charging at the same time.
3. They can easily be connected to most all elec start generators, and automatically start / stop the gen at your desired battery bank voltage points. This can really extend the life of your expensive batteries, and your generator will last longer
Magnum Inv / Chargers are compatible with most major generators, including Onan, Powertech, Generac, Westerbeke, Kohler, EPS, Northern Lights, and most portable generators with electric start.
Auto Gen Start settings do not interfere with the manual start / stop operation of the generator. Just wire into any existing start / stop switch for the generator.
4. Remote controls are available
Offers multiple functions in one place, including: inverter on/off, charger on/off, shore power breaker settings, AGS control, meter button, setup, and technical menus.
Adjustable settings include shore power input from 5 to 60 amps; AGS settings for voltage, temperature, quiet time, clock, and status; inverter and charger settings for search watts, battery bank size, battery type, charge rate, VAC dropout, contrast, and power saver; and tech settings for battery temperature, transformer and internal FETs, software revisions, and factory reset.
5. Run much larger loads from smaller generators.
(With our new "Hybrid" MSH Magnum inverter / chargers only)
Most inverters only use one source of energy to power loads, either from incoming AC power – shore or AC generator – or from the batteries. The MSH-M Series combines the energy from both sources to power loads. This allows the inverter to recharge the batteries when there is surplus power or deliver more power to the loads if they require more than the AC input can supply by itself. A fully charged battery bank with a 3000W inverter combined with a small "super quiet" type generator like 2000 watts can still power big loads with a lot less gas and noise