Shore Power Without Charging?

JeffroNC

We will returning to our TAB 400 in January. It is currently parked at our kids house and it might be frozen when we get there. I have lithium batteries without temp protection. The main switch is off and the solar is disabled. 
Am I correct that if I leave the switch off, I can use the electrics without charging the batteries until it gets warmer?

pthomas745

No, the switch also turns off power to the trailer.  The issue on lithium batteries is they cannot be charged below freezing.  If the solar is "off" (charging can be turned off in the Victron app on the settings page) and the trailer is not plugged in, you can turn on the switch and use battery power.

And: the odds of your batteries being below freezing inside a warm trailer are...really low.  It is the batteries themselves that must be "below freezing" for low temp charging to be an issue. 

AnOldUR

Yes, the battery switch being turned off will isolate your batteries from WFCO charging while on shore power but the WFCO will still supply power to your trailers 12V devices. The only thing that bypasses the battery switch is solar, so (as you said you have) be sure to turn off charging in the app (or pull the fuse at the solar controller if you don't trust the tech).

Edit to say that I have a 2020 320S. Your 400 may be different?

Horigan

AnOldUR said:

Yes, the battery switch being turned off will isolate your batteries from WFCO charging while on shore power but the WFCO will still supply power to your trailers 12V devices. The only thing that bypasses the battery switch is solar, so (as you said you have) be sure to turn off charging in the app (or pull the fuse at the solar controller if you don't trust the tech).

Edit to say that I have a 2020 320S. Your 400 may be different?

This is the correct response.  The 400, at least my 2019, is the same.

AnOldUR

Off topic, but this got me thinking of my inverter install. Connecting it through the cutoff would have required larger wire from the switch to the batteries, so I got lazy any went directly to the battery. It is fused, but there's no cutoff except for the inverters power switch. Should this have a cutoff?

Denny16

Inverter’s are normally connected directly to the battery, or have their own battery cutoff switch.  The TaB battery cutoff switch is only 40 amps and the inverter would fry it.  On the TaB400, nüCamp wires the inverter directly to the battery, only thing you can have in series at the battery is the negative side voltage metering shunt, which is rated for the load an inverter would place on it.
 Cheers