Inverter Capabilities

[Jmreim]

I'm new to inverters and the new (to me) boat I recently purchased has an 1800 watt Xantrex inverter. I'm trying to understand what that can run and under what conditions.
For example, can the TV be on while I'm underway (it is setup to mirror my MFD)? Can I watch an LCD TV at anchor (no genset) and if so, for how long?
Any help would be most appreciated and sorry to be so ignorant on this subject.
Jim

 

[O C Diver]

Most likely yes to all of your questions. You will want to determine if the inverter is pure sine wave or modified sine wave. Pure sine wave plays well with everything within 50% of its wattage capacity. Modified will have problems with some things that require a pure sine wave.

Ted

 

[MYTraveler]

What you really need is a meter that will tell you, in real time, how much electricity you are taking out of your batteries, how much remains, and how long that will last. With that, you adjust your loads accordingly. The good news is those meters are readily available -- they are called State of Charge meters, and sometimes Battery Monitors. And they are relatively easy to hook up. When you are charging, they tell you how much electricity is going into the batteries, and after some experience, you will know how long before recharged (as the batteries reach 100% capacity, the rate at which you can put electricity in slows way down; In fact, when charging off a genset that would not otherwise be on, it is common practice (at least with FLAs) to stop charging when the batteries hit 85%, and to never run them below 35% -- thereby using only the middle 50% of capacity. The good meters also tell you about the health of your batteries by comparing how many more electrons you have to put in than you take out, and by determining (automatically) how much capacity your batteries have (it diminishes over time).

 

[Comodave]

Compass Marine has a good review of the new Balmar SOC meter.

 

[DavidM]

As others have noted, yes to your questions. How big is the house battery bank that powers the inverter? That will determine how long you can run various appliances.

For example, a smallish tv of 19" or so draws about 50 watts. I takes roughly 5 amps DC to make 50 watts AC. So if you have a 200 amp hour house battery bank it will take 20 hours to bring it down to 50%, the most you should discharge a battery for decent life. Of course other DC house loads like the fridge, lights, water pump, etc will contribute to the discharge rate.

David

 

[Jmreim]

The inverter is a Xantrex Proline Sine Wave 1800 and it does have a meter at the helm but I haven't figured it out yet.
Library Archive

There is also a Xantrex LinkLite installed on the boat - perhaps that augments the Inverter meter to provide additional info?

 

[Wxx3]

Cheap battery monitors

I have a Victron, but if I was buying now, I would look at these cheap monitors, from Will Prouse. I really like this kid.

https://youtu.be/E6O76Okmt0

 

[Slowmo]

Inverters are generally rated for continuous output. So an 1800W inverter can easily power an LCD flat screen TV which draws only 50-100W. Most inverters also have a peak rating for transient loads (motor start), yours should have a 2900W surge capacity. What you'd have to watch is running multiple appliances at the same time. For example do not run a microwave and hair dryer at the same time.

The key question on how long you can run is the size of your house battery bank (amp-hours). As stated above, you can't access 100% of your battery capacity. For simplicity I normally assume that 50% of the capacity of the battery bank is available to power equipment before its time to recharge.

If you have the Xantrax LCD remote panel that WILL provide the meter function both for energy in and out of the batteries. I leave my panel set to monitor amp hours in/out of the house battery.

If you're underway then the alternators should be charging the batteries so you should be OK assuming you have at least a 45A alternator. In my case the AP is the biggest power user underway.

 

[DavidM]

The Prosine's control panel shows DC volts and amps and AC watts. Take the amp reading while you are watching the television and divide it into half of the amp hour rating of your batteries. That is how long you can run off of the batteries with no other loads.

David

 

[caltexflanc]

You would be very well served by getting yourself a copy of Nigel Calder's "Boat Owners Mechanical and Electrical Manual." It will be perhaps the single most referenced tome on the vessel. The first three chapters are devoted to inverters and electrical issues. Read it and then you can come back with situation specific issues that will be more helpful. Such as your battery system, including capacities, functions and charging sources.

Your inverter is a max of 15 amps AC... the capacity of most outlets. All your AC devices will have wattage ratings on them too.