Confused about where my power is going.

[Nillerk]

So I finally got the trailer all wired and went out for the weekend and the 600ah battery bank that I was expecting to have about 7.200KWH of reserve ran out after only 2.5KWH according to my Victron setup. Wondering if anyone can help me shed some light on this.
System:

• Victron Multiplus 12/3000 125-50
• Raspberry Pi with VenusOS
• Victron SmartSolar 150/100 (no panels yet but connected to DC bus)
• 2 - 12V 300Ah CATL LiofePO4 packs with JBD BMS connected to the system with Louisvdw/dbus-serialbattery plugin
• Victron Lynx Distributor DC Bus

Before connecting the batteries, I top balanced them and then did a capacity test and got over 300ah on both packs
I think that perhaps the system can only report 1 battery in the VRM calculations so I may have gotten 5KWH

Here is the consumption from the time in question:


Today, with the batteries at 100% again and being in float for 2 days, I unplugged the AC and simulated some load in the trailer (turned on lights, furnace, tv, plugged in laptop)
Here is what it looks like running:

I used the wiring diagram found here:

30A Camper - 1200W Solar & 3000W Inverter Upgrade - Wiring Diagram

This wiring diagram is for RV's with factory 30A shore power and will show you what you need to install up to 1200W solar and a 3000w Inverter to your existing electrical system.

www.explorist.life

This is what my setup looks like:

 

[Q-Dog]

Do you have a smart shunt or battery monitor?

 

[Diysolar123]

A few thoughts...
1)I do not see a shunt, without a DC shunt right at the battery you actually do not know what your true load is(reading voltage is useless)
2)keep in mind all your equipment is always pulling a fair amount of current, put a clamp meter on it and see what the "idle" drain is
3)good thing you did a capacity test so you "know" what you have; check your connections and carefully measure (voltage and current across each device so you can see what is going on, although a battery shunt makes it a lot easier to see what the battery is really doing); what are your disconnect limits set at?

 

[cinergi]

VRM does not include DC loads in its Consumption calculations. The "DC Loads" is a calculated (not measured) instantaneous value and is notoriously incorrect. That said, an additional 5kWh is a lot; verify your DC loads manually or shut them off entirely (Inverter only) for your testing.

 

[GSXR1000]

your furnace doesn't show up on your multiplus...
how did you do the original capacity test. what did you use to measure with

 

[Nillerk]

what did you use to measure with

https://m.aliexpress.com/item/32821877897.html?trace=wwwdetail2mobilesitedetail&spm=a2g0s.9042311.0.0.70ce4c4dbzdY3p

your furnace doesn't show up on your multiplus...

Why would my furnace show up on my multiplus? It just runs on the a dc circuit with propane

 

[GSXR1000]

https://m.aliexpress.com/item/32821877897.html?trace=wwwdetail2mobilesitedetail&spm=a2g0s.9042311.0.0.70ce4c4dbzdY3p

Why would my furnace show up on my multiplus? It just runs on the a dc circuit with propane

maybe I am confused... I was thinking your multiplus was showing your power consumption? what method are you using to see how much your battery is being used?

 

[Louisvdw]

@Nillerk nice setup you have.

2 things to remember in this setup:
1) Your MPPT will draw power. So while you do not have PV panels installed yet I suggest you disconnect that. The SmartSolar MPPTs are very smart, but they still use power (between 5W-10W on mine which is only 20A 48V model). In a system with panels installed Victron program the MPPT to shut down until a few minutes before the MPPT started producing power in the previous few days. So during the night it draws almost 0W and it only starts searching for the max power point from the panels around where it expects the panels to start producing. In your scenario with no panels my guess is that it will search all the time, thus you will see power drawn if you add those graphs on your VRM.


2) My driver is not yet capable of using 2 battery modules. There is a ticket for multiple banks that you can subscribe too to get updates on. Only when that ticket has been completed will your 2 modules give you all the results in VRM.
So what you are seeing in VRM will just be for 1 of your batteries. There is more information on this from a test one user gave feedback on in the Victron forums. So your actual usage would have been more 5KWH (2.5KWH+2.5KWH)

By the way these BMS use a shunt for their power measurements, so there is no reason to install another shunt as mentioned earlier. You can even calibrate the BMS shunt if you really want to in the app.

 

[Nillerk]

@Nillerk nice setup you have.

2 things to remember in this setup:
1) Your MPPT will draw power. So while you do not have PV panels installed yet I suggest you disconnect that. The SmartSolar MPPTs are very smart, but they still use power (between 5W-10W on mine which is only 20A 48V model). In a system with panels installed Victron program the MPPT to shut down until a few minutes before the MPPT started producing power in the previous few days. So during the night it draws almost 0W and it only starts searching for the max power point from the panels around where it expects the panels to start producing. In your scenario with no panels my guess is that it will search all the time, thus you will see power drawn if you add those graphs on your VRM.
View attachment 50476

2) My driver is not yet capable of using 2 battery modules. There is a ticket for multiple banks that you can subscribe too to get updates on. Only when that ticket has been completed will your 2 modules give you all the results in VRM.
So what you are seeing in VRM will just be for 1 of your batteries. There is more information on this from a test one user gave feedback on in the Victron forums. So your actual usage would have been more 5KWH (2.5KWH+2.5KWH)

By the way these BMS use a shunt for their power measurements, so there is no reason to install another shunt as mentioned earlier. You can even calibrate the BMS shunt if you really want to in the app.

Thanks for the feedback. Any thoughts on when the 2nd BMS functionality will be ready?

Here is the charts for my MPPT

 

[Louisvdw]

My 2nd BMS is still in China waiting to be completed and shipped. I've been waiting more that 2 months as there was no RS485 chips available to complete the order. Sounds like we might be seeing some progress soon, but then it still needs to be shipped to my location.
I can't see that there will be any progress on the multiple modules functionality in the next month.

 

[HOU_Castle]

@Nillerk nice setup you have.

2 things to remember in this setup:
1) Your MPPT will draw power. So while you do not have PV panels installed yet I suggest you disconnect that. The SmartSolar MPPTs are very smart, but they still use power (between 5W-10W on mine which is only 20A 48V model). In a system with panels installed Victron program the MPPT to shut down until a few minutes before the MPPT started producing power in the previous few days. So during the night it draws almost 0W and it only starts searching for the max power point from the panels around where it expects the panels to start producing. In your scenario with no panels my guess is that it will search all the time, thus you will see power drawn if you add those graphs on your VRM.
View attachment 50476

2) My driver is not yet capable of using 2 battery modules. There is a ticket for multiple banks that you can subscribe too to get updates on. Only when that ticket has been completed will your 2 modules give you all the results in VRM.
So what you are seeing in VRM will just be for 1 of your batteries. There is more information on this from a test one user gave feedback on in the Victron forums. So your actual usage would have been more 5KWH (2.5KWH+2.5KWH)

By the way these BMS use a shunt for their power measurements, so there is no reason to install another shunt as mentioned earlier. You can even calibrate the BMS shunt if you really want to in the app.

Be mindful that inefficient (aka cheap) inverter can pulled 3A/hr to 10A/hr when is on and idle.

 

[Nillerk]

Be mindful that inefficient (aka cheap) inverter can pulled 3A/hr to 10A/hr when is on and idle.

I'm not sure I would classify a Victron Multiplus as a "cheap" inverter.
Either way, it does have a low draw switch that switched the ac to a pwm on low power draw.

 

[HOU_Castle]

You may want to use elimination process to find the root cause. It will take time. But its worth, especially for safety reason.
For example, check and test batteries for their self discharge rate. If the batteries are good, then check all wirings, make sure no damage (this can cause partial grounding, which will drain your batteries) and etc.