MultiPlus-II - Power Inverter - Pure Sine Wave Inverter Charger for 120 amp Battery - with PowerAssist Technology - 3000VA 12-Volt

Victron stuff is the best of the best for diy solar, seriously. The Multiplus II is totally awesome, super reliable, and loaded with features. Keep in mine Victron inverters use VA instead of Watts so they are not really 3000 Watts. But honestly, I love these units. They are so capable and dependable, and you can set them up to do a ton of different things, even connecting with smart home stuff. It costs a lot but you get peace of mind and expandability with these, It's working perfectly right now, and I hope it stays that way. I actually bought 2 units during the buy 1 get 1 free promo to set up a split-phase system so I am very ecstatic about the deal!

Both the inverter and the warranty are extremely good. You will need additional equipment like wires and data cable adapters, it's a sophisticated piece of equipment that can be used many different ways. You'll need to learn to install it correctly. Use 6AWG romex wires directly in the AC terminals and ignore the comments about adding ferrules to the wires, thank me later. Watch some youtube videos, this is a critical detail with these AC terminals, if you shove the end of an extension cord in those AC terminals, it might work for a few days and then stop working. It really does need to be a thick solid piece of metal, and it helps if you relax the clamping terminal with a 2mm micro flat screwdriver when you slide the wire in. Use the wire stripping illustration on the inverter to ensure you strip enough wire before going into the AC terminals (my original batches production model doesn't have this warning sticker). When you tighten the DC lugs, use a torque measurement driver, they are tinned brass rather than stainless steel, if you are tightening them with a large ratchet, it's EASY to tear the lugs in half. You'll need to buy a MK3-USB (or the usb-c version) cable to configure this inverter, unless you use a cerbo (comms hub/VenusOS), connect with canbus and configure it online through VRM Portal. I don't use a cerbo, I use a raspberrypi4 instead for a comms hub (also VenusOS), so I need the MK3-USB cable to connect my monitoring/comms anyway because a raspberrypi4 does not have a canbus port. With the default settings, the battery charger will be in storage mode--presumably so it doesn't destroy someones' battery bank by charging it to an undesirable voltage. That's one of the biggest reasons that you'll still need to program it unless you buy it from a distributor who takes for of the settings for you. If you're doing an advanced setup, there are many other reasons you would need to configure it.

the Victron 3000VA multiplus ii is HEAVY due to all the Iron in the transformer: this allows it to store a lot of power in the magnetic field that will reliably start up motors that pull a BIG Inductive load. Note: this 3000VA (volt*amps is NOT watts) unit puts out about 2400w as i understand it. BUT it has the huge surge capacity that's needed to handle inductive loads like AC and refrigerator motors. the Victron 3000 starts my 2 500w ACs, plus a dehumidifier ~500w, + fan (air purifier) and still has 800w for my microwave oven. it handles the input surges that occur when the clouds clear from the sky w/o a problem. (it logs over & under voltages) this unit is not cheap because it has so many features like a transfer switch, & ground relay. it has two AC outs, the second one can be programmed to, say, run a water heater only when batteries are charged and spare input power is available. my only complaint is the password problem. the default password is usually six zeros, 000000, But ... Victron plays games & says " sometime the password is randomly set at the factory & must be cleared and reset by the user." this is BS for "the unit was returned & we tech it but don't reset the password the user entered" this units would not take the pw default, but instead used the secret "zzz" password... Victron says nothing i could find about the zzz pw ( it was all over the web) but tells you the secret password is only available to professionals who have taken their instructional course! Also the AC outputs don't accept cables with lugs, only bare wire & the manual says that AWG 6 is the minimum wire gauge when awg 6 is close to the max AWG guage. overall a very robust unit!

This is a beast and I haven't been able to trip it into overload in my stand along, solar powered shop yet. Continuous loads are 12, 4 ft. LED lights plus some smaller over bench lights, tool battery chargers, massive computer, stereo with two amps driving two sets of speakers. Just for fun on top of everything else I ran my table saw, my insanely power hungry heat gun, my 1000W water distiller, bench grinder and drill press and it just hummed along. Checking the metrics via the Victron VRM showed no more than a 1 volt drop on the AC output and an almost immeasurable 60 hz fluctuation which is better than I get from the power company. It is HEAVY my friends, and don't think for a minute you'll be able to mount this by yourself above shoulder height. I did it it, and it was super sketch... Is it expensive? Yes, but it's designed in the Netherlands and manufactured in Taiwan and the Quality Control is exceptional. Can you get the same specs for less? Sure, but you'd never get the metrics and rock solid performance Victron delivers. Don't let the voltage graph freak you out, I have a high of 120.30V and a low of 119.5. We're talking a 0.8V Delta.

Seems to work good. Nice to be able to add the Bluetooth. The only complaint I’d had to by a USB interface to be able to program charger adjustments. Too bad they don’t have that on the APP.

Very reliable, very versatile, can be easy or complicated that's up to you how far you take it. Integrated well with home assistant. Don't expect a lot of help from the vendor.

Its Victron, of course it works great! Excellent efficiency (48v 200ah battery bank) Super customizable with the RJ45 to USB3 dongle!

Powers my RV great company to work with

Victron has quality products and work great. The only reason for the 4/5 is the need for ferrules which needs more special tools that are normally not needed and won't be used again