Great! Now that we've covered the information one needs to really get an understanding of their battery capacity needs, based on how they use their Leisure. Let's look at the next big component, the Inverter. I agree with DiverBob, I like to define the various components/functions I need for a project and then see what is available on the market. I forgot to add earlier, that before you start any electrical project, you really need your coaches wiring diagrams. They are very easy to get , just send Leisure's Willie Neufeld,
WNeufeld@tripleerv.com, an email with your VIN#, email address, and phone number. Requesting him to send me, via email, the PDF versions of your Leisure's 120vAC and 12vDC electrical systems wiring diagrams. Then follow it with a call to him (877-992-9906 ask the operator to connect you to him) and leave a message on his voice-mail of what your email requests. He will very promptly send a single or multiple emails transmitting your electrical system wiring diagrams. Here is a thread,
https://sprinter-source.com/forums/index.php?threads/92289/, that has some diagrams on it already that may match your Leisure. If you do get wiring diagrams please consider posting them on this thread, it may just help someone else.
Now let's consider how our coaches work on batteries (12vdc) and shore/generator/inverted power. Our coaches are equipped with a power distribution panel/box (120vac breaker/12vdc fuse box) and an inverter. Here is a simple chart (not intended to show every detail) that shows the simple power distribution on a 2014 Leisure. Different model years have differences on power distribution panel/box model and model/size Inverter/Charger, so this is why having the wiring diagram for your model/year/floorplan is important. But conceptually the functions are the same. If you look at post #27 here,
https://sprinter-source.com/forums/index.php?threads/91673/page-2, you'll see a lot more detail on the panel differences and wiring. I'm going to get to that and everything on the chart thru later posts, but for this post I want to focus on power distribution.
As you can see power comes from 3 sources; batteries, shore/generator or solar (if equipped) power. The batteries support everything in the coach that runs off 12vdc, which the batteries supply. It either feeds those things directly or thru the 12vdc fuse box side of the power distribution panel/box. The batteries also supply the Inverter which converts the 12vdc battery voltage/direct current (dc) to 120vac (120 volt alternating current, same power as your house uses for household appliances or high amp draw equipment like air conditioner, microwave, hair dryer, washingmachine/dryer, stove/oven, etc.). In my 2014, I only have a 600w (6a) Inverter, so it can only supply about 6 amps, which Leisure connected 2 outlets to this Inverter. So I can only use it to supply low amp simple things like tv, satellite, phone chargers, small LED lights, a curling iron, etc. or I will trip the breaker on the inverter. The inverter is also wired into one breaker on my 120vac power distribution panel/ breaker box so when on shore/generator power those 2 outlets are powered (but still limited to 6a, even though the wiring can support 15a) that way instead of having to always use batteries to supply those 2 outlets. This capability of the inverter is called pass-through. The inverter uses the battery power to supply the 2 outlets or it passes-through the shore/generator power to the outlets. This is a very desirable feature for any inverter. My inverter doesn't have a battery charger (charges the batteries when on shore/generator power) with it so we'll cover battery charging later in a subsequent post.
The solar power also charges the batteries, which are supplying the coach. So if your solar system is supplying 10a (12vdc) and the coach/house is using 10a then your batteries stay at 100% charged. We'll discuss battery charging and solar input later on in this thread. But keep the potential solar system on the back burner.
Now the 120vac breaker panel side of the power distribution panel/box is connected to the Automatic Transfer Switch (ATS) which is supplied by 120vac from either Shore power hookups or from the generator. The ATS senses which 120vac power supply is available and sends it to the 120vac side of the breaker box. My power distribution panel/box is a WFCO 8955, which also includes a battery charger and a converter that converts 120vac to 12vdc, so when I'm hooked up to shore power or using the generator, my house/coach batteries get charged and the coach gets supplied with 12vdc so the batteries don't have to. I think Leisure switched to a WFCO 8930/50 in 2016, which doesn't have these extra features, rather they went with an inverter that has a battery charger (that charges the house batteries by pass-through power from shore/generator) and rely on just the batteries to supply all 12vdc to the coach.
So in looking at the 120vac side of the power distribution panel/breaker box, you need to decide what functions, or all of them, you want to be able to run off batteries. Because you need that information to determine what size pass-through style Inverter you need. You'll want an inverter that has a battery charging function as well, but we'll look at that part of it later. I just want to focus on figuring out what size Inverter you need. So here's about how the sizing goes. Everything in your entire coach runs off of a 30a 120vac power supply, so that means you'll need at least a 3000w Inverter to run those same things off your batteries. And remember when running the 120vac side of the house things off batteries, you are also still supplying all the 12vdc items from your batteries. So now you are running absolutely everything in your coach off batteries, including the air conditioner. This distinction is important because that's what you need to remember when determining how much battery capacity you think you need. Remember to consider the difference between 120vac amps and 12vdc amps (10a 120vac = about 110a of 12vdc power) for battery capacity needs! If you want to just run most everything, including the microwave but not the Air-conditioning, then you'll need at least a 2000w inverter. If you just want to supply the outlets up to their 15a rating, water heater, entertainment systems, etc. Then you'll need a 1500w inverter. If you only want some of your outlets supplied up to 12a, and entertainment systems then a 1200w inverter is fine. And then if you want a couple of 10a max outlets a 1000w inverter is fine. You can use this understanding of the power distribution to start thinking what size Inverter you want. If you know you want at least 2000w of capabilities and aren't sure if you want to add the air conditioner operation to the batteries, then my advice is to select a 3000w Inverter, because there is only a couple hundred dollars difference between the two. Selecting a 3000w Inverter gives you the ability to expand your system to add the air conditioner later. I like to choose components that give me future options if I am undecided on some things. But based on the experiences that others have shared, it seems most decide that more is better! The same with batteries, size your wires with the possibility of adding more, but we'll get into that more later. If I've missed something on power distribution please chime in.