Is there a way to see the internal temperature of Multiplus II ?
Hi @ron_h,
No, there is not.
Ok thanks,
Maybe an idea to add this in next firmware?
I do see a drop in performance during charge and discharge after a while.
How can I see which of the 3 phase Multiplus II is limiting the current (is overheated)?
Ron
Overheating != limiting power. Overheating is an error on the inverter. Of course, there is a dependency on temperature and inverting power, but all of this is a normal operation mode and not overheating.
I don’t see the overheat led turning on, I just do see a drop in performance.
I can transport a lot of energy, have 3x 15kWh battery.
At beginning I see a total current measured by lynx shunt of 289A after 1h it drops to 235A.
IR pictures shows that the casing is quite hot at transformer position.
Maybe there is a way to improve cooling, did see in some pictures of opened Multiplus II the internal Fan isn’t placed in a tunnel.
You could make a lid between mosfet bridge and Fan to boot Fan performance I think.
But that would mean I have to open mine new multiplus,…
Maybe someone tried this already?
Ron
Its normal to get lower power from them if they are hot, ist called temperature degrading and is in the specs
temp alarm kicks in when they are really hot and need to cool down
There are several mods out there to improve cooling
I replaced the fans in my 3 multiplus 2’s because of noise and more airflow, i also placed 2 smaller fans underneath each multi to help airflow
Also i have a separate room for the installation with fresh air from outside when needed and warm air is vented out if temp is to high inside the room
Is the system situated in a climate controlled environment?
With that kind of power available I would hope so.
I stay under 25 degree air temperature, so according datasheet one inverter would be able to output 4kW, so in 3 phase total 12kW.
They drop until just above 10kW after 2h.
Ron
Could I change the internal fan with one with more flow?
The internal fan PWM output how much amps can it handle?
And what fan is now used?
You will have to open it to see the specs of the current fan, then get a fan with the same or lower specs (Watts/Amps, same voltage) but that has more airflow
Hi Guy @guystewart
Do you have an MP2 at hand and willing to do a small experiment, please?
I don’t have one and I am asking because, considering the fact that it can charge batteries, so it can behave like a charger, maybe it’s possible that the firmware to be able to supply that information on the 0xEDDB (VE_REG_CHR_TEMPERATURE) register.
Or do you know for sure that it can’t?
Thanks in advance!
I don’t believe that it will ever be possible considering the way the internal temp sensors are wired within the MP.
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I usually put the inverter temp sensor that comes with the unit (calibrated onto the cerbo gx temp sensor) on to of the inverter where the air blows out. Then the data is there can be shown on the vrm dashboard
The ruuvi works too if you want to be more serious about monitoring.
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I suspect this is a policy decision rather than a technical limitation. I don’t know about inverters but MPPTs have that info but it’s not published. As you know there are ways around that limitation but those don’t work for everyone. Curiously, if your MPPT has a screen, you can see the numbers there.
F.
Ok, why did victron wire all PTC’s in series, to less analogue inputs?
And the fan PWM is positive switched, normally you switch to gnd, a lot easier in design.
How many amps can the PWM handle?
Ron
Mppts publish the temperature in victron connect app. You can see it there either locally(Bluetooth connection) or remotely (vrm access), but can’t in remote console,nor in vrm gui.
Hi Ron. Same topic was discussed in old community, I even believe that several times. The best treat I found was this
https://communityarchive.victronenergy.com/questions/57433/multiplus-internal-temperature.html
Even including images how to 
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In Connect app I only see mine Cerbo GX and lynx shunt, none Multiplus II.
So I must install a separate temperature senor to monitor temperature,…
As @lxonline already mentioned, I also use the tempsensor, that is delivered with every Multiplus2 to monitor (or at least to have an indication of) the temperature. I just put it into the fan’s blow-out area on top of the Multiplus2.
You can then activate a widget in VRM and display the temperature there. Unfortunately it is displayed as battery temperature. Don’t know if is possible to change this, but its fine to have this indication.
And yes, the MP2 will degrade according the datasheet, and this starts quite early at 40°C, as far as I remember.