Putting together a Victron package and need a little help

[chowder]

I’m finally pulling the trigger on solar. I’m leaning towards Victron smartsolar 100/30. I have a few questions though. 1. Do I need the BMV 712 to compliment the 100/30? I was under the assumption that the Bluetooth connectivity between the charge controller and my phone would do everything the BMV 712 would offer. 2. Should I get the Victron smart battery sense to monitor battery temp and voltage? 3. What else would you guys put in this kind of system ie. inverter, 12v 120v battery charger, dc/dc battery charger etc. Battery is SOK 200 ah and 320w or 360w panel. Pretty standard electrical needs similar to most on here. Trying to shoot high to buy me extra days and compensate for shade and cloud cover. I look forward to your thoughts and opinions.

Thanks.

 

[Jon R]

The BMV 712 measures the current in and out of the battery and mathematically integrates the measured current over time to track the state of charge relative to a 100% charge datum. The Victron Smart MPPT 100/30 does not do that. Its display options don’t provide any automated state of charge indication. It only provides voltage and current in and out of the charger.

 

[Vic Harder]

+1 to what Jon R said. They measure/show different things. The MPPT is charging and monitoring what it does with the solar power coming in, the BMV monitors the state of the battery.

Less $$ than the BMV is the Victron SmartShunt. Same data, but just bluetooth vs having a small dial readout.

Start with that and then determine from your usage patterns what else you need.

 

[heinphoto]

Both the BMV and SmartShunt can also measure battery temperature with an optional sensor. If you join the SmartSolar mppt and BMV/SmartShunt in a VE. Smart Network, then the mppt will use the battery voltage, current, and temperature reported by the BMV/SmartShunt in its charge control algorithms.

 

[Jon R]

I have the BMV 712 installed in my camper and I like having the display available there as does my wife. That said, I tend to use the phone app more than the display.

 

[chowder]

Awesome. Thanks for clarifying. That will get me started.

 

[Jon R]

Regarding the OP’s question 3, I would definitely want a DC to DC converter/charger sized so that I can accumulate battery energy for one day’s camper operation in about 2 hours of driving. For me that meant a 30 amp charger. This accounts for cloudy days, forest camping, or a failure of your solar system.

I have two 200 watt panels and a 200Ah battery. Two comments:
1) In my experience having only two or three times the panel capacity that’s sufficient on a sunny day will not compensate for the effects of overcast. Overcast cuts the output to about 10% of panel rating. If you are going to camp in clouds or in the forest you want a way to charge at a decent rate from your truck alternator.
2) If you have a pop up camper, try to get one large panel instead of multiple panels to reduce the weight on the roof.

 

[buckland]

following this thread ...very informative. I think it is a great idea to get a smart shunt and will. If one has two LiFePo4 batteries in parallel am I right ...after watching the Victron youtube video... that using the two ports one can monitor both batteries separately? ... Or is it considered "one Battery bank" ?

 

[Vic Harder]

Not sure about that. I know it can be done, but I thought that was with two 6V batteries? Also, you can do that OR monitor temps, but not both.

 

[Jon R]

To clarify, my understanding is you can EITHER fully monitor a primary battery bank (voltage, current, integrated state of charge) and monitor the voltage of a second battery (like your truck starting battery) OR you can fully monitor a battery and the temperature of that battery.

(This is for the BMV-712. I don’t know if the smart shunt is different. )

 

[heinphoto]

Yes, that is correct. With either the BMV-712 or SmartShunt you can either measure a second battery (typically the starter battery or midpoint of two batteries in series) or the battery temperature. If you want to measure battery temperature, you have to purchase the optional sensor cable. I initially monitored the midpoint of our dual 6V batteries, but switched to the temperature sensor so the mppt could do better temperature compensated charging.

 

[pvstoy]

The monitor will only show you the current voltage of a second battery. It will not give you a state of charge information. Just wanted to point that out if a prospective buyer is mislead.

 

[Rhian]

I’ve spent the day trying to figure out why I can’t get ‘midpoint’ to work - it sets off an alarm and says the difference is 99.9%. I checked the connections and fuses of the red B1 and B2 wires. They look good. I finally came across something on the Victron community support site - 2 12V batteries wired in parallel cannot be monitored separately. They shunt sees them as only 1 battery. I’ve now changed the setting to ‘none’ but have not yet removed the B2 wire. Hope this helps others with the AUX option on the BMV 712.