[larry barello]

Use at least #2 for the inverter. 2x#4 is the same as #2. I find lugs and connectors to be problematic and suggest you reduce connections wherever possible. I.e. #2 (or 00) rather than multiple wires. (I used #4 between the batteries. Ok, but a tad light)

20a charge controller should be fine for 400w of solar. #10 wire should be fine for most circuits. #14 should be fine for your actual 12v loads.

The alternator should really be a proper charge controller and, depending on the run should be #4 wire as a depleted battery will draw a lot of current.

I think the separate shore circuit is a great idea. I wish I had done that.

I would put in disconnects between the battery and everything else and on each external power source (alternator/solar) and the load center. This is for convenience as well as protection. Appropriate sized resettable thermal breakers are convenient. Use a quality brand. I use mechanical products.

Consider a combo a solar/alternator charge controller. I have had good results with the Renogy unit and I see other reputable brands have competing product (kisae). Less wiring (see above) and better battery management.

 

[larry barello]

The IceCo fridge says .545kwh(24hrs), so converting that to amp hrs I get 45.417.....so that number should be divided by 24(if it''s running 24 hrs a day)? Sooo, 1.89 ah average?

Your math is good. The last sentence is where you went off the rails.

You basically understand what the issues are and how to solve them. You are only guilty of overthinking the problem - that is not a criticism, I totally did the same as would anyone doing this the first time!

Refrigerator energy use depends upon the ambient temperature. Normal room temperature is where the unit is tested. A cool interior will use less. Hot, more.

For reference: My wiring diagram

 

[larry barello]

Shore ground bonded to van. In your case inverter also bonded to van. This is what a proper inverter/charger provides for bonding shore power vs. inverter power:

(Renogy inverter/charger manual)

I don't know what the old Kisae inverter provides. I assume it handles bonding internally.

From above:
My wiring diagram (above) is pretty much what I recommend with the exception that the B2B to house should have a disconnect. This isn't for protection but more for convinience.

The high power breakers from Bluesea, Mechanical Product and Optifuse all seem to work as advertised. No-name breakers are not so good. I have a box of them to prove it. Quality doesn't necessarily mean more expensive if you use MP or Opti.

Others may disagree with my minimal-protection philosophy. I am assuming everything is close together so putting a breaker/fuse on a 20" length of #2 is super irrelevant. Even #4 will pop the 175A main battery breaker/fuse easily without bursting into flames.

I don't know about a thermometer for the Kisae. On the Renogy units it is used to modify the Lead Acid charge profile and has no other function for LiFePO4 other then to cut off charging if the temperature drops to 0C.

 

[larry barello]

OK, you guys are killing me. The Kisae inverter is model # IC122055. Looking up the specs, ....

IC122055 – Kisae Technology Inc

I see this:
Features include:

• True sinewave output to run motor loads and sensitive electronics without hum or buzz.
• Multi-stage charger to charge your deep-cycle batteries quickly and efficiently to manufacturer’s recommendations.
• Integrated transfer switch to switch seamlessly from shore power to battery power.
• Ideal for running appliances & consumer electronics the way they were designed to be.

Soooo, now I am vacillating on using it to its full potential, or by-passing some neat features.........{sigh}

As long as you have the inverter/charger, USE IT. Less wiring. It will manage your battery when plugged into shore power - super usefull if you are not driving and it is winter and cloudy

For my use case, shore power is rarely used. But it is convenient when needed!

 

[larry barello]

Sheesh is right!

My opinion is to keep it simple. Minimal doodads. Make everything do double duty (i.e. get thermal breakers which can be used as the disconnect). Use integrated electronics to minimize part count and wires (the Kisae or Renogy charge controllers). Be smart, get smart batteries that can be connected (via wire or Bluetooth) and display their status (temps, current, voltage, SOC). No shunt needed! Save money! I have been pretty happy with the Renogy Smart Lithium, with the wired display panel (not so much their phone app).

Your inverter doesn't seem to be lithium aware, but, as you pointed out, it is close enough for the occasional use. Solar/ALT will handle the balancing, etc. during normal use.

 

[larry barello]

Note that display is probably just a volt meter and while very useful for troubleshooting it won't really give you a reliable state of charge since 60% of the time from 0% to 100% is like 0.2v apart.

you sure of that? I tried finding a data sheet on that battery and couldn't. @Motor7 , what did it say?

 

[larry barello]

Couple of problems:

1. The charge controller does not appear to be attached to the ground except via a long thin wire back to the outfitters panel.
2. There is no mechanism to disconnect the solar.
3. There is no mechanism to disconnect the alternator.

Charge controllers rely upon accurately measuring the terminal voltage of the battery to operate properly. The alternator and the solar can be variable, can have thin wires, can have lots of voltage drop it doesn't matter. The controller will up convert or down convert as necessary to accurately charge the battery. But if the controller cannot measure the battery voltage it can't do its job.

Disconnects on the power sources is just plain convenient for diagnostics and maintenance purposes.

Remedy:

1. a couple of low amperage thermal breakers make dandy disconnects.
2. The kisae house battery connections should be to the shunt and the disconnect (as close to the battery as possible.)
3. The service battery return should be a short stub from the shunt to the chassis. Running a separate wire back to the upfitter panel is wasteful and won't perform as well.

Editorial:
Why a 300A fuse on a battery that cannot support 300A and an inverter that will never draw 300A? I think y'all are fixating on the wrong stuff. The 2x100A fuses on the batteries is sufficient for everything. Personally, I would just use a quality 175A thermal breaker for both the disconnect and protection of the main battery. I do appreciate the goof-proofness of the individual fuses on the terminals though @GaryBIS correctly noted they are redundant and introduce more losses (fuses and thermal breakers work by generating heat: loss of power) Each one is probably dropping 1/10 volt. String a few together, along with switches and you have .5-.8v loss which means your inverter will LV fail well before the battery is dry.

The dual disconnects for solar also mystifies me. There is some serious voodoo going on here: Solar is inherently safe and current limited. Ditto for the lithium batteries (if you trust the BMS) - not so much for Lead Acid that can pump out 1000A into a dead short without breaking a sweat.

A residential solar panel running 75-100v and a few kilowatts is a different beast. I'd use dual disconnect there for sure!

 

[larry barello]

Can we talk about battery monitors? I don't need bluetooth, but do want a monitor that does two batteries independently. Leaning towards simple......:
Samlex BW-03 Battery Monitor

This seems pointless. The batteries are tied together with heavy wire. They will NEVER have different voltages. The Kisae remote panel (and I am guessing here) will show you status of your service battery (and solar and house).

The "shunt" display should give you the remaining information you need to know (battery SOC). Consider the EcoWorthy battery monitor. It uses a current sensor and is super easy to install.

 

[larry barello]

Larry,
I'm updating my diagram. Eliminating the bus bars and tieing the grounds via the shunt(except for the one's required by Kisae to go separately to chassis. I have a disconnect for solar and one for the batteries to Inverter.
The 300Amp is what Kisae recommends for the inverter in the manual.

The case to ground (Kisae charge controller and inverter) is just a basic safety connection in case the guts of the unit somehow fail. It is more important for the inverter which pumps out dangerous voltages than for the charge controller. Electrically all grounds are the same. The reason to use a single point for all returns is to avoid ground loops where high currents from one segment interfere with another.

I dunno what to say about Kisae's recommended fusing. Sounds like engineering "cover your ass" design principle vs. something that actually protects the system. Totally doesn't make a shred of sense. The Kisea inverter probably has a large "inrush current" (capacitors) when initially connected to the battery that probably exceed 300A, but it is of such a short duration that even a 100A fuse would not be bothered.

As noted elsewhere, the 2kw inverter will not be capable of drawing more than 180A for more than a few seconds. That is why I used a 175A breaker. It will handle 175A continuously and 130% (230A) for a variable amount of time (0-30) minutes before tripping. Good enough for me. It never takes very long to cook or make coffee and I rarely use more than 1200wt at a time although I sometimes try I did draw 175A (2kw output) for 10 minutes w/o trouble in testing.

NB: all thermal protection doodads (breakers/fuses) are relying on something getting hot. Ambient temperature and the mass of the stuff connecting to the protection doodad will affect the trip point. So, your actual experience may vary depending upon lug weight, wires size, number of lugs, etc. Nothing to worry about, but just an interesting tidbit. For our purposes the protection is to shut down the system in the case of a dead-short (which should never happen if you enclose your electrical system). Wires that run across the van are, by definition, more exposed and can fail due to abrasion, etc. That is why all those MUST be fused at the source. It is all about failure modes you are trying to avoid and your tolerance for risk.

 

[larry barello]

Larry, isn't the EcoWorthy a Hall effect monitor? Personally, we elected a shunt-based monitor in the belief that the latter was more accurate.

Yes, it is hall sensor. Just like a clamp on current meter. It should be accurate. In my testing it was generally close to the values reported by the internal shunts of the Renogy Smart Lithium batteries. I don't really have the tools/skills to determine absolute accuracy. In part shunt/hall-based devices need calibration, although, potentially, they can be self-calibrating with properly determined endpoints. However, for simplicity and minimum number of failure points in the high current loop, the EcoWorthy seems attractive.

I chose 100% Renogy, at the time, in a drive for simplicity and minimum connections. Combo charger, Smart Lithium + display and have not been disappointed although I do have "Victron Graphing Envy". So, I satisfied my electronic gadget itch making my own graphs (user: promaster, pw: forum). So much for simplicity