Regarding the optional temp sensor for the 712 unit, will adding this option alter the way the charging works or is it just a display reading?
My batteries are mounted in the hulls of my Catamaran and I live in the tropics, so I could see the advantage of adding this feature if it is going to change the behavior of my Smart 75/15 chargers by providing them with info to help them properly charge my batteries based on temps.
Thx.
Yes this will enhance the battery charge parameters.
As you already stated, if you purchase the additional temperature sensor for the BMV-712, then you can create a VE Smart Network where the voltage & temperature data from the BMV-712 is used to better charge your battery.
The BMV voltage will account for any voltage drop in your MPPT cables & the BMV temperature data will be used for accurate & real time charge voltage compensation (due to temperature).
Please also note that the inbuilt temperature sensor in the MPPT only takes a reading in the morning just before the MPPT wakes up. That same temperature is then used for charge voltage compensation for the rest of the day - so it's not ideal & you can achieve a much better charge by using the BMV data.
As you already have a BMV-712 there is no need to consider a Smart Battery Sense (unless you have already used the 2nd input for something else like mid-point measurement).
Thanks for the confirmation Mark, that’s what I was hoping to hear.
I’ve learned not to assume things work they way I think they will!
I’ll defimtiely get one installed now that I understand it’s benefits.
No problem.
I agree that it's always best to check/confirm rather than to assume.
FYI this is the related extract from the VE smart networking manual;
https://www.victronenergy.com/live/victronconnect:ve-smart-networking
Thanks again Mark. Ordered and on the way!
Even though I live in the tropics where we rarely see much fluctuation in temps, lately I’m adopting an all bets are off philosophy when it comes to climate. It’s been cold (for Hawaii) so it’ll be nice to have more accurate temp readings, especially if without the optional sensor the charge behavior is based only on a one time wake up measurement as you say. There’s a big difference between early morning conditions when on trailer in my driveway versus out on the water all day in the sun.
if you purchase the victron smart sensor (bluetooth) then this would connect to the smart mppt and the bmx712 and yes the smartsolar mppt unit would adjust for temp and for volt drop as well
Thanks, but I was asking about the optional temp sensor that can be wired into the second terminal of the shunt that comes with the BMV-712.
Since the 712 is already networked with my two Bluetooth MPPT 75/15’s it is transmitting voltage readings to my chargers, and I assume if I add the optional temp sensor it will send that info to them as well so that they can adjust their charge cycles based on battery temp instead of the temp measured by the chargers which are housed in a separate area, but I just wanted to make sure first since it’s possible it’s just a feature for monitoring that has no affect on the chargers behavior.
I assume if I install a sensor, the VictronConnect App will report that the BMV-712 is transmitting both voltage and temp and that my two 75/15’s are receiving when networked.
I’m not sure I get your question but if you are only talking about your solar MPPTs charging your batteries, then as it seems you are using:
https://www.victronenergy.com/blog/2018/03/22/voltage-temperature-sense-for-solar-chargers/
Then temperature and voltage are already used when networked.
The optional temperature sensor you refer to for the BMV gives a readout of the battery temperature on the BMV-712 Smart or it can do midpoint voltage monitoring or monitor a starter battery instead. Apologies if I’ve not entirely understood your question.
To add to the above see:
Thanks for the info, but I’m not using a Smart Battery Sense and am pretty sure the BMV-712 and it’s shunt have the ability to do the same thing since my BMV-712 is already networked with my two MPPT 75/15 chargers via Bluetooth.
It’s talked about in the manual and available as an optional accessory -a temp sensor specific for the 712 that you wire to terminal 2 of the shunt, the same terminal you would use if you instead wanted to monitor the voltage of a starter battery or measure mid point voltage of your bank.
What I’m trying to determine that the manual doesn’t address, is if the measured temp which is transmitted to the BMv-712 via the shunt from the attached sensor is then shared with the controllers via Bluetooth when networked, and if this info is actually used to better charge the batteries, or if it’s just info you can “monitor” like a temp gauge in a car.
If the info will actually better charge and protect the batteries, or even provide a better accuracy of capacity, I’ll spend the extra bucks and install it -especially if my 75/15 chargers are currently using built in sensors to determine temp. My chargers are mounted in a small waterproof housing exterior of the boat while the batteries are in the bottom of each hull, so the conditions are definitel different.
