Victron charge controller - Temperature

[67cj5]

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.

I found this PDF from the place I bought my 100/20 but it also covers the one you have, The places where I bought mine states that they have some kind of softwhere to run with these smart controllers,

Hope this helps.

https://www.sunstore.co.uk/wp-content/uploads/2018/01/Victron-SmartSolar-Charge-Controller-MPPT-75-10-75-15-100-15-100-20.pdf

Here Is most of the basic info about them.

Victron SmartSolar MPPT 75/15

Victron SmartSolar MPPT 75/15 A solar charger gathers energy from your solar panels, and stores it in your batteries. Sunstore recommend customers use the Victron SmartSolar MPPT 75/15 with solar panels up to 220w (12v) and 440w (24v)

www.sunstore.co.uk

 

[hour]

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.

I just got everything assembled and created a network from the BMV. I don't have the option to create or join a network from the 75/15 though, so I don't know how I can pair these two items together. I do have the option that you showed for low temperature cutoff and when tapped it shows a dialog with a warning, "This setting only takes effect when the charger is configured in a VE.Smart network where battery temperature is available" which I'm not, to my knowledge, considering I never set it up and have no options to do so.

Any suggestions? Firmware is fully updated on everything. Also I see you have equalization voltage set. What's that about? Mine defaulted to 0 when I selected the lifepo4 preset. Thanks!

OH $#@! me. Some post on the Victron support board, "The current software on my Victron VE.Bus Smart Dongle doesn’t have any option for joining a smart network." I use the dongle because I bought my controller right before they released the controllers with bluetooth built in. If I have to buy an upgraded charge controller from these dildos to have temperature monitoring from my BMV, I'm boxing everything back up and returning it. I'm already pissed that I've had to purchase four items from their sprawling ecosystem.

 

[john61ct]

All Victron gear's manuals are posted online at their site.

Color Control GX supports their comms protocols, which they publish. Also their Venus unit.

VE Direct is one for example.

Their user forums are monitored by their designer and support engineers, and in NA you can contact Justin Larrabee +1 207 3540493 · jlarrabee@ victronenergy.com

Bur you really are supposed to work with a good dealer.

 

[john61ct]

FFR really best to do the research, or if nothing else just ask here, before placing orders.

 

[Alloy]

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

By that range do you mean 5-10F (-12C) is OK to charge lithium?

I looked into Silicone heating pads. Wasn't a good application. Liquid is the way to go.

 

[pdxfrogdog]

I just got everything assembled and created a network from the BMV. I don't have the option to create or join a network from the 75/15 though, so I don't know how I can pair these two items together. I do have the option that you showed for low temperature cutoff and when tapped it shows a dialog with a warning, "This setting only takes effect when the charger is configured in a VE.Smart network where battery temperature is available" which I'm not, to my knowledge, considering I never set it up and have no options to do so.

Any suggestions? Firmware is fully updated on everything. Also I see you have equalization voltage set. What's that about? Mine defaulted to 0 when I selected the lifepo4 preset. Thanks!

OH $#@! me. Some post on the Victron support board, "The current software on my Victron VE.Bus Smart Dongle doesn’t have any option for joining a smart network." I use the dongle because I bought my controller right before they released the controllers with bluetooth built in. If I have to buy an upgraded charge controller from these dildos to have temperature monitoring from my BMV, I'm boxing everything back up and returning it. I'm already pissed that I've had to purchase four items from their sprawling ecosystem.

Boooo.... and as you have by now surmised, my 75/15 is the SmartSolar model, not the BlueSolar one.

 

[john61ct]

By that range do you mean 5-10F (-12C) is OK to charge lithium?

Follow published specs for those specific cells, but personally I'd avoid below freezing at all, and keep to under .1C until 40F or so.

Winston claims much colder from their Yttrium doping, but color me skeptical.

I looked into Silicone heating pads. Wasn't a good application

Why not?

 

[john61ct]

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.

Ya no sorry, thinking in Celsius there

 

[luthj]

At low temperatures, the mobility of the lithium ions is reduced. What happens, is that at higher charge rates, the anode can become plated by lithium metal. The Anode in these batteries is a type of microporous carbon. The lithium molecules normally settle into the "gaps" between the carbon atoms. At low temperatures the lithium atoms mobility in the electrolyte is lower. If the charge rate exceeds the rate at which the lithium atoms can move into the anodes lattice, instead they create a solid metallic layer on the anodes surface. This block the pores, and is generally not reversible.

The charge rate at which this starts to occur i somewhere between 5-20% of C. Consult the cell makers info for details, the temperature does vary from MFG to MFG, and is dependent on many factors, including cell surface area, and electrolyte mix.

So for lower charge rates, generally you are okay.

 

[hour]

Boooo.... and as you have by now surmised, my 75/15 is the SmartSolar model, not the BlueSolar one.

Yeah :| I had two choices, spend $50 for an upgraded VE Bus bluetooth smartwhateverdingydongle or $118 for another new/upgraded 75/15.

Bought the new 75/15. I could have upgraded size but I don't have any more room for solar with 200w on my roof. I'll use the old unit and its incompatible ve bus dongle for my trailer which runs lead acid. Don't even have permanent solar for it because I cringe at the thought of applying permanent tape to the roof for the flexible panel I have available, but if nothing else I can monitor SOC.