Victron charge controller - Temperature

[hour]

Pretty sure I've read that the smaller Victron charge controllers have internal temperature sensors. But all search results across the web for victron+temperature discuss temperature compensation, and the most it touches on lithium is "set this to 0 in the app".

I don't want to charge if it's anywhere near freezing, and my charge controller is like 2 feet from where my new lithium pack will live.

So the question is - can anyone confirm a temperature sensor in the 75/15 and other smaller Victron controllers, and if it exists, can it be used to prohibit charging when it's cold? I don't think I've seen anything like that in the app settings.

Even their 'Smart Battery Sense' bluetooth temperature sensor product video just talks about its use for temperature compensation. Same with the wired probe that can attach to the Battery Monitor.

I don't want to buy anything if the charge controller has one built in, it can work for blocking charging, and my battery and charge controller share the same environment. One more wireless connection to go awry. One more piece of Victron gear to purchase.

 

[john61ct]

No, even quality controllers just feature temperature compensation, not for protection cutoff.

That is a BMS function, isolate the bank from the charge buss at one temp, from the loads buss at a much lower one.

Ideally adjustable.

Note Winston claim to allow charging at colder temps, but have not seen that verified in the field.

 

[Alloy]

I think a BVM712 is needed. It reads the battery temp sends it to the controller(s) if the VE network is set up.

The inverter/chargers have a temp. sensor but I don't think the info is sent to the network . . . . best to confirm though.

 

[hour]

I think a BVM712 is needed. It reads the battery temp sends it to the controller(s) if the VE network is set up.

The inverter/chargers have a temp. sensor but I don't think the info is sent to the network . . . . best to confirm though.

Cool, I ordered the 712 with temperature sensor today. And yeah guess that'll still send info to the controller via VE network. Prayers that works fine even though they'll be all of two feet from one another. Still would prefer the reliability of a wired sensor.

And thanks john, you must have the 411 on legitimate BMS setups that I can't manage to find.

 

[Alloy]

Victron's online info could be improved but when needed customer service makes up for it.

I think a Color Control is needed or Venus (with a seperate display) to link a BMV to a conroller(s) .....but confirm though.

https://www.victronenergy.com/upload/documents/Datasheet-BMV-712-Smart-EN.pdf

 

[pdxfrogdog]

Cool, I ordered the 712 with temperature sensor today. And yeah guess that'll still send info to the controller via VE network. Prayers that works fine even though they'll be all of two feet from one another. Still would prefer the reliability of a wired sensor.

And thanks john, you must have the 411 on legitimate BMS setups that I can't manage to find.

I'm running a similar setup: BMV 712 sharing temp/voltage with a 75/15 charging a LiFePO4 battery. I can confirm that when the MPPT controller starts receiving temp from the BMV, you are then able to set up temp compensation (which you want off for lithium) and a custom low temp cut-off on the charging side... which is exactly what you want.

 

[pdxfrogdog]

A caveat to what I mentioned above, both my Victron devices are bluetooth capable... that is how they communicate on the VE Network.

 

[dwh]

I think a BVM712 is needed. It reads the battery temp sends it to the controller(s) if the VE network is set up.

Yes, but even if it does pass temp data to the charge controller...is the charge controller going to only use it for lead-acid temp compensation...not as a low-temp cutoff for lithium?

Probably.

That's an issue that Victron might need to address with a firmware update for the charge controllers.

 

[hour]

Yes, but even if it does pass temp data to the charge controller...is the charge controller going to only use it for lead-acid temp compensation...not as a low-temp cutoff for lithium?

Probably.

That's an issue that Victron might need to address with a firmware update for the charge controllers.

Looks like pdxfrogdog covered that in the post above yours, confirming that their battery monitor (and assuming smart sense bluetooth temp monitor) will provide that to the charge controller and allow low temp cutoff

 

[pdxfrogdog]

from VictronConnect, looking at battery section of the MPPT controller:

 

[dwh]

Looks like pdxfrogdog covered that in the post above yours, confirming that their battery monitor (and assuming smart sense bluetooth temp monitor) will provide that to the charge controller and allow low temp cutoff

Yea, saw that after I posted, then had to run and do something so I had no time to fix it. So, you're good to go then.

 

[Alloy]

Keep in mind that if the battery is against an outside wall, in a cabinet or on the floor the temp sensor may not be on the cold side of the battery.

 

[john61ct]

Actually that's fine, it's core temp that matters, with big cells it takes a long time for that to change if ambient is fluctuating widely, e.g. only getting below freezing at night.

 

[Alloy]

Actually that's fine, it's core temp that matters, with big cells it takes a long time for that to change if ambient is fluctuating widely, e.g. only getting below freezing at night.

We'll be out when the high side of the fluctuations reach 5-10F and before we trun the heat on in the trailer the batteries might be 20F.

 

[john61ct]

In that range charging at low C rates is still OK.

Discharging even more so, they'll just be inefficient.

Lower than that I'd start to consider an insulated box with silicon pad warmers covering the floor automatically governed by a thermostat