What do you experts think of this solar+battery+inverter system for my small RV?

[MegaMosquito]

-13F seems cold but I think this is doable with self heating. Especially inside a compartment.

In a compartment, that I think will be "near room temperature" (or warmer).

 

[MegaMosquito]

24V is looking pretty good to me now, but I remember reading somewhere that the rule of thumb is to use only up to 1kW of A/C loads with a 12V system, up to 2kW loads on a 24V system, and then to use 48V systems if you will ever have loads greater than 2kW.

What do you all think of this rule of thumb? It seems easy to buy a 24V 3kW inverter, so maybe it's fine to exceed 2kW?

 

[SoggyShoes]

I'm just not a fan of the Lynx Shunt. Prefer BMV-712, 702 or Smartshunt with temp sensor.

......

@sunshine_eggo why are you not a fan of the Lynx shunt?

Do you like the Lynx distributor and power in?
If so, how do you connect them?

I have seen a system where they used the Lynx distributor with to the left of that, a bmv-712 and bus bars instead of the shunt and power-in.

What would your preference be?

 

[SoggyShoes]

@MegaMosquito the other nice thing about a 24v system is that you can easily use the Victron 12v to 24v charger from your alternator. This way when you are driving the engine can aid in charging your system. I don't think Victron makes a 12v to 48v charger.

I am doing this in the system I am installing. I will then be using another 24v to 12v charger to go from my 24v system to my 12v house battery (which I am switching from 2 6v lead acid to one 12v 304Ah LFP battery). This allows me to be able to leave all my existing 12v stuff alone. I think that was what @sunshine_eggo was suggesting.

I am ordering my batteries from Amy at Luyuan (https://szluyuan.en.alibaba.com). They were significantly less expensive (but literally are on the slow boat from China). I have never ordered anything direct from China before, but she seems to have a better reputation that most of the US companies for several years. So far, she has been awesome to work with. She can make custom cases for your batteries. Or you could make your own case that might better fit your closet.

 

[sunshine_eggo]

@sunshine_eggo why are you not a fan of the Lynx shunt?

Expensive. No BT, VE.CAN only. Must be used with GX device.

Do you like the Lynx distributor and power in?

No. Expensive. No or limited class T fuse options.

If so, how do you connect them?

Bus bars and wires.

I have seen a system where they used the Lynx distributor with to the left of that, a bmv-712 and bus bars instead of the shunt and power-in.

What would your preference be?

No Lynx products.

 

[SoggyShoes]

Expensive. No BT, VE.CAN only. Must be used with GX device.

No. Expensive. No or limited class T fuse options.

Bus bars and wires.

No Lynx products.

Wow! It must be true for you to say not to use blue!

So do you recommend a similar layout as the Lynx with a positive and negative bus bar for the batteries on one side. The BMV-712 in the middle with the chassis ground. Then on the other side a positive and negative bus bar that has feeds from the inverters, MPPT solar controllers, and DC-DC chargers in and out?

 

[Brucey]

Wow! It must be true for you to say not to use blue!

So do you recommend a similar layout as the Lynx with a positive and negative bus bar for the batteries on one side. The BMV-712 in the middle with the chassis ground. Then on the other side a positive and negative bus bar that has feeds from the inverters, MPPT solar controllers, and DC-DC chargers in and out?

By the time you look for decent bus bars the lynx power ins aren't a bad value .

 

[SoggyShoes]

By the time you look for decent bus bars the lynx power ins aren't a bad value .

View attachment 212079
View attachment 212080

So @Brucey that looks like you are just not using the Lynx shunt, and instead using a SmartShunt and a breaker instead. And they are connected by 4/0 on the power-in side and solid copper bus bar material on the other.
Is that correct?

Edit: @Brucey what size (rating) shunt and breaker are you using?

 

[Brucey]

So @Brucey that looks like you are just not using the Lynx shunt, and instead using a SmartShunt and a breaker instead. And they are connected by 4/0 on the power-in side and solid copper bus bar material on the other.
Is that correct?

Correct, as eggo mention the lynx shunt is expensive for what it consists of, the value option is the smartshunt for $111, I'm using a cerbo-s so the limited Bluetooth range versus the 712 wasn't an issue as I'm connected using ve.direct. that's a midnite mnedc 250A DC breaker.

I'm using 1/0 cable there, I only have about 2kW of load right now.

Amazon.com

 

[Brucey]

It's the 500A one.

The other option you can do is 3d print an enclosure that holds a smartshunt plus a victron shutoff switch to keep it all seamless:

Victron Lynx - Battery Switch + Smart shunt enclosure by RobrechtDR | Download free STL model | Printables.com

Enclosure for a Victron 275A Battery Switch and a 500A Smart Shunt, based on the enclosure for the Lynx Shunt VE.Can. | Download free 3D printable STL models

www.printables.com