Ingo Posted September 11, 2020 Posted September 11, 2020 I decided to add a VE.Bus Smart dongle to my Multi and suddenly my charge voltage just dropped. If I disconnect it it restores to normal. Any idea why this would happen? *I do have an existing wired sensor connected to the battery. Quote
Ingo Posted September 11, 2020 Author Posted September 11, 2020 2 hours ago, plonkster said: No idea, ask on Victron community? I've done that but they are not as helpful as this forum. Quote
Ingo Posted September 13, 2020 Author Posted September 13, 2020 Ok, so for anyone finding this post and have similar concerns. I did some tests and the VE.Bus Smart Dongle overrides both Quattro connected as well as GX connected temperature sensors. While the GX sensor was connected I held the Smart dongle in my hand to increase the temperature and the charge voltage started to drop even though it's confirmed by VictronConnect to be in 'Secondary Mode'. The documentation states that it should be the other way around, all other sensors should override the Smart dongle data. I've now removed this device from my system. Quote
introverter Posted September 14, 2020 Posted September 14, 2020 On 2020/09/13 at 9:42 AM, Ingo said: Ok, so for anyone finding this post and have similar concerns. I did some tests and the VE.Bus Smart Dongle overrides both Quattro connected as well as GX connected temperature sensors. While the GX sensor was connected I held the Smart dongle in my hand to increase the temperature and the charge voltage started to drop out of interest and possible completeness for anyone with a more useful contribution that stumbles on this, @Ingo is your system: ESS consisting of Quattro + Venus GX + Battery + 1 wired temp sensor connected to Quattro + 1 wired temp sensor connected to Venus GX and then also try to add VE.Bus dongle ? Is this on a (Bluenova?) LiFePO4 battery with comms? If so, why the two external temp sensors even before the VE.Bus dongle is added - does the BMS not provide voltage and temp info to the Venus GX? I am curious about the potential role and conflicts of an ESS system with BMS provided voltage+temp info and TWO extra external wired temp sensors (Quattro and Venus) and now a potential third voltage+temp source (VE.Bus dongle). Something in the victron manuals leave me with a hunch that a single source of both voltage and temperature (like the dongle) could be bumped up the pecking order over a source that only provides one or the other. Even then, should this override BMS info? Any other assistants running? @plonkster IF the BMS provides voltage+temp info, I would assume no external temp sensor should influence charge voltage? Quote
Ingo Posted September 14, 2020 Author Posted September 14, 2020 Nope, here is the setup: No ESS, Quattro + Venus GX + Lead-Acid Battery + 1 wired temp sensor connected to Quattro + 1 wired temp sensor connected to Venus GX and then also try to add VE.Bus dongle. Dongle added with either Quattro Temps sensor alone or Venus Temps sensor alone, the VE.Bus dongle overrides either/both. Document states any other Temp source has priority and then lists "EG. CANbus" only but my gripe is with the first part stating 'any other source' has priority. I think the person that developed the Smart Dongle code only considered CANbus to be a priority instead of all other sources as well. Possibly small oversight but impact is that I can't use the device at all. No assistants running as my long-standing ACOut2 Relay Assistant that doesn't work on 'micro grid breaks' no one wants to acknowledge and or even look at - my peeve with a certain company's Support process (sorry). introverter 1 Quote
___ Posted September 14, 2020 Posted September 14, 2020 1 hour ago, introverter said: F the BMS provides voltage+temp info, I would assume no external temp sensor should influence charge voltage? When the BMS provides a charge voltage, the Multi assumes the BMS has already done any temperature compensation and will not add anything extra to it. In other words, for most people with managed batteries (ie with CAN-bus connection), no need to bother with temperature. The battery already handles that. Mmmh found the post... https://community.victronenergy.com/questions/61583/vebus-smart-bluetooth-temperature-overrides-venus.html introverter 1 Quote
Ingo Posted September 14, 2020 Author Posted September 14, 2020 I Totally agree. Once I go LiFePO4 all these extras are coming off and then it will work as advertised, but unfortunately not as it stands today. Quote
___ Posted September 14, 2020 Posted September 14, 2020 Found your site... House 'your surname'. Poking around now. Quote
___ Posted September 14, 2020 Posted September 14, 2020 Your temperature sensor selection is set to "default". A decision was made not to be too "smart" about auto-selecting one, because people do really weird things. They put a sensor in their freezer on their boat, forget to configure it properly, and next thing we're overcharging the batteries because it's -15°C. So the only sensor (that is not connected to the Multi) that will be used automatically is a temperature sensor connected to the battery, in other words, a BMV-702/712. All others must be explicitly selected. So just select the temperature sensor under System Setup. Quote
Ingo Posted September 14, 2020 Author Posted September 14, 2020 6 minutes ago, plonkster said: Found your site... House 'your surname'. Poking around now. Go for it!!! Quote
Ingo Posted September 14, 2020 Author Posted September 14, 2020 5 minutes ago, plonkster said: So just select the temperature sensor under System Setup. Forgive me for being a bit daft but I don't see that under System Setup. Quote
introverter Posted September 14, 2020 Posted September 14, 2020 https://www.victronenergy.com/media/pg/2556-GX_Device_Manual_Venus_GX/en/dvcc---distributed-voltage-and-current-control.html ___ 1 Quote
___ Posted September 14, 2020 Posted September 14, 2020 I'd do it for you, but you have a password on it Quote
Ingo Posted September 14, 2020 Author Posted September 14, 2020 7 minutes ago, introverter said: https://www.victronenergy.com/media/pg/2556-GX_Device_Manual_Venus_GX/en/dvcc---distributed-voltage-and-current-control.html DVCC is Off. Quote
Ingo Posted September 14, 2020 Author Posted September 14, 2020 6 minutes ago, plonkster said: I'd do it for you, but you have a password on it Try now. I removed it but didn't reboot. Quote
___ Posted September 14, 2020 Posted September 14, 2020 2 minutes ago, Ingo said: DVCC is Off. Aaaah... that has to be on, or it won't work. With a lead acid bank that's not going to cause anything unwanted. Also, turn off SVS, SCS, but turn on STS (shared temperature sense). And then select the sensor. Which I have done already for you. The extremely long text for the temperature sensor... that is fixed in Venus 2.60. Quote
Ingo Posted September 14, 2020 Author Posted September 14, 2020 1 minute ago, plonkster said: Aaaah... that has to be on, or it won't work. With a lead acid bank that's not going to cause anything unwanted. Also, turn off SVS, SCS, but turn on STS (shared temperature sense). And then select the sensor. Which I have done already for you. The extremely long text for the temperature sensor... that is fixed in Venus 2.60. Thanks. I try to be n-1 with firmware, or until enough time has passed for me to see the open issues won't affect me. And Yes, that is the correct temperature, I will now go and plug the dongle back in and warm it up a bit to test but I am sure it will work. A note perhaps: Maybe the documentation could be a bit clearer when it comes to this dongle and other sources not being from a BMS. Quote
Ingo Posted September 14, 2020 Author Posted September 14, 2020 And here we go... dropping dropping and more dropping after the VE.Bus dongle is plugged back in. Temperature on the dongle is 28 degrees with the actual temperature being 20 degrees. See the drop reported by VRM portal. Quote
___ Posted September 14, 2020 Posted September 14, 2020 1 hour ago, Ingo said: dropping after the VE.Bus dongle is plugged back in OK for some reason the temp is not written to the Multi. grrrr. Quote
___ Posted September 14, 2020 Posted September 14, 2020 OK, this was another bug fixed in Venus 2.60. I patched it in place. Try it now. Ingo, introverter and fredhen 3 Quote
Ingo Posted September 14, 2020 Author Posted September 14, 2020 (edited) Excellent! The temperature reported on VRM, and on the VenusGX remote console for the Multi, is now the correct value and the voltage has gone up to +- the value before you enabled DVCC. Is the configured temperature correction value in the Multi, for the charger, still used or is it a different internal value from the GX device? Edited September 14, 2020 by Ingo Quote
___ Posted September 14, 2020 Posted September 14, 2020 (edited) 2 hours ago, Ingo said: Is the configured temperature correction value in the Multi, for the charger, still used or is it a different internal value from the GX device? The temperature sent from the GX device merely overrides the temperature reading from the Multi. The voltage compensation adjustment is still done by the Multi. In an ESS system (not sure if you run that, probably not), the compensated charge voltage from the Multi will then be sent to the MPPTs as well (in other words, the Multi is in complete control). In a non-ESS system (aka off-grid), the temperature is sent to the solar chargers and the Multi, and each one does its own compensation depending on the coefficient it has configured (so you probably want to make them the same). But I don't see an MPPT at your site either. Edited September 14, 2020 by plonkster Ingo 1 Quote
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