charger question dealing with low temp

[scottyfz6]

Okay first the system is in a large teardrop so its mobile.

I have 2 - 60 amp lifepo4 batteries and a victron shore power charger. Right now I have a switch on the power bank that activates a thermostat that controls 2 - 12 watt bee hive heater pads under the batteries, and a relay that interrupts the charge from the victron shore power charger. The relay is set up so the charger goes thru the NC contacts, so when the switch is off, or the thermostat says the batteries are warm enough it just passes the power thru.

I will eventually be adding solar, I just saw an older thread about the victrons can be disconnected post charger as long as the charger is programmed properly. When I add the solar charger I want to also have it shut off on the low temp like the shore charger.

So I do a second ( or go to a double pole ) relay or could I just run both chargers thru the same relay. I kind of see it like both chargers are going to the same battery anyway, whats the big deal about connecting them sooner in the circuit.

Bad idea?

 

[snoobler]

The Victron SCC has a setting for low temp protection. Connect direct, and enable the feature. It won't charge below 0°C or whatever threshold you set.

 

[scottyfz6]

Thanks I did not know the scc had that as an option. Its also not in the manual.

 

[snoobler]

It might be model dependent, but I would have expected it to apply to all new solar models. I don't know if their shore units do.

 

[scottyfz6]

It might be model dependent, but I would have expected it to apply to all new solar models. I don't know if their shore units do.

I know the shore power does not.

edit I just confirmed it has temp comp not shut off.

 

[snoobler]

Which solar are you looking at?

 

[scottyfz6]

The victron 75/15 blue tooth, but that will be in the spring.

Edit see my edit above

 

[snoobler]

I would couple it with a $40 smart battery sense or a BMV-712 to get a better voltage and temperature reading.

You can see that with firmware updates, this feature has been added to multiple models including the Phoenix smart charger:

VictronConnect changelog and beta releases [Victron Energy]

www.victronenergy.com

 

[Dzl]

I know the shore power does not.

edit I just confirmed it has temp comp not shut off.

Are you certain, looking at the app for the 75 / 15 (in demo mode), it looks like low temperature cutoff is available if you switch to (1) expert mode, and (2) the user defined charge profile.

 

[snoobler]

Agreed. I forgot about the demo mode. The 75/15 definitely has it.

I tried the Phoenix smart charger, and it did too. User defined battery AND expert mode enabled it.

 

[scottyfz6]

Are you certain, looking at the app for the 75 / 15 (in demo mode), it looks like low temperature cutoff is available if you switch to (1) expert mode, and (2) the user defined charge profile.

I have the 120 volt shore charger right now. I will be doing the solar in the spring. The 120 volt shore charger does not have it. I am in expert and custom profiles.

 

[scottyfz6]

 

[snoobler]

I don't know what the shore charger is. I haven't seen Victron identify one by "shore."

 

[scottyfz6]

its the ip67 smart charger. it plugs in to 120 volts. Sorry a boat term.

Blue Smart IP65 Charger (120V and 230V) - Victron Energy

The Blue Smart IP65 Charger is the new professional battery charger with built-in bluetooth. Find a Victron Energy dealer near you.

www.victronenergy.com

 

[snoobler]

Shore is a common enough term for RV's as well. I'm not versed on the IP stuff.

Anyway, I don't see that it's ever been added to the IP67, but looping back around to the original question, demo mode indicates the 75/15 MPPT has that function, so you don't have to do anything with relays and whatnot. Simply connect it directly to the battery and enable the protection.

 

[scottyfz6]

Know I know that from your reply early makes it easy when I get there. So thanks for that.