Victron EnergyMultiPlus-II Pure Sine Wave Inverter Charger for 35 amp Battery, 120V, 3000VA 48-Volt

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.

This, coupled with four 100AH 24V LiFePo3 batteries, makes for a great long-term (4-8 hours) UPS system for much of our home. Originally intended to keep our business' network equipment up in our absence, I found the load from most of our lighting and outlet circuits was low enough to be included, along with a furnace, sewage pump, fireplaces, and microwave. This gives us plenty of uptime if we're away from our home for the day, as well as time to set up generators for the critical components.Installation does require a solid understanding of electrical circuits and load requirements, along with experience in residential or commercial wiring.

I was very excited to install this unit and surprised to see how quiet it was. The unit stopped working after a day of use, spoiling my fridge contents in the process, and no lights are turning on the unit. There is only a 30 day window period and I am out 1500. I really expected better from VictronEdit: This company took the old unit back and repaired it at no extra cost! Happy camper

Works perfect. Had a slight problem with first one ordered. It disappeared in transit via UPS. Contacted Amazon.....Second one showed up in 2 days with Amazon shipping.

I learned after purchasing that it's not possible to configure the Multiplus-II without forking over more money to Victron for a proprietary $70 USB adapter or spending hundreds on their proprietary protocol equipment (Cerbos GX). They clearly took a page out of Apple's business ethics handbook. How is it legal to sell a product that is effectively dead on arrival unless you purchase additional proprietary equipment?

So far I like this overall but was hoping it would be a replacement for all the plug in UPS’s I have all over the house. But after a few months, it seems this will not be so. It is somewhat unreliable in its automatic switch over when the power goes out. If I turn off the breaker directly at the panel it works every time, but when the power goes out about 1/2 the time it just shuts down. Not really helpful seeing that it was for backup of important systems. I have had to re-install the UPS’s up stream of this to keep everything from shutting down when the switchover fails. I find that the problem is more apparent on the roll over back to mains power. When it works it keeps everything running on the initial switchover but everything shuts down when it switched back to mains power. Not what I was hoping for but maybe in time I can dial it in and make it work more as planned. I have tried adjusting count out and in voltages etc but that has not yet seemed to help.

The quality exceeds what I expected

I'd give this thing 5 stars for just about every category except one.. the installation . The AC in and AC requires you to put Ferrules on the wires. It would be much better if they would just use nuts like they do on the DC side. Also where the cables enter the device at the bottom appears to have 3/4 inch holes, but they don't accept the standard 3/4 inch conduit connectors ( the holes are just a bit too small ). They do have nice rubber stoppers over those holes that can be cut to provide a snug fit around the cables to keep bugs and the like out, but if your wiring code requires conduits between it and your circuit breaker box you may be in for a challenge trying to find something that will fit. In the picture I attached, I was able to use 3/4 PVC conduit and the insert was from a piece I had purchased from Home Depot that had connectors on both ends. Its not designed to be used the way I have it shown there but it works. Of course I need to push the conduit up on the connector more before mounting.Update 2/2/2024 Unit still working perfectly, I have half the circuits in the house on it and it makes a great UPS for out home offices. 4 to 6 hours with 4 lead acid 12v batteries is more than enough for our Generac to kick in only 30 seconds later if street power fails. We have a large power pull so If I was doing it again I'd get 2 of the 10k versions and then do whole home which would include the AC and Stove.