TV 12 v—charge

jbajor

When towing, should the 12v from TV be charging battery?  M VictronConnect shows it is not. 

Denny16

Depends on the TV, and it’s alternator setup.  Most modern new vehicles reduce the alternator output when the vehicle is in higher rpm’s, and charge the battery at lower rpm’s.  Many do not out out enough to charge both the vehicle and trailer battery, unless it has a larger alternator setup for towing.
 Cheers 

Sharon_is_SAM

Can we see a screenshot of the battery monitor?

jbajor

  Here is monitor with engine running on TV. No change in battery voltage whether running or not. I confirmed 12v pin is ‘hot’ and brake controller is getting 12v from it.  

Sharon_is_SAM

I don’t think the solar charge controller monitors current entering the battery from the 7 pin.  Someone correct me if I am wrong.  

jbajor

I totally agree, however, by monitoring battery voltage I would expect to see the voltage level increase with charge from 7-pin...  

Sharon_is_SAM

Well, provided your battery switch is on, there will be a draw from the LP/CO alarm, USBs, frig, etc.  Maybe the incoming current is offset by the draws?  Most only act like a trickle charger anyway.

jbajor

7 pin only acts as a trickle charge?  That would make sense then..  I guess I was assuming that one received a sizeable charge from the TV...  thanks 

VictoriaP

@jbajor It can, but you need an adequate sized wire from the alternator to the 7 pin (rarely installed as a factory default on an SUV, usually a fairly narrow gauge is installed), and either an oversized alternator, a second alternator, or a DC-DC charger. Of these, the first two are again, rare on SUVs straight from the assembly line, the third is a 3rd party mod.

Generally speaking, a trickle charge is pretty much what you’ll get from most vehicles. If you want more, your best bet for an aftermarket setup is to run a heavy gauge 12v wire from the alternator and add a DC-DC charger. Victron makes several, and there are a few threads here from people who installed them.

jbajor

Victoria, great data!  Thank you!

MarkAl

The Screen shot of the solar controller only shows what your panel was delivering. With the small solar voltage and 11 watts it must have been pretty cloudy or low light on the array. Only a shunt (e.g. Victron Smartshunt) connected directly to your battery will give you the total of solar and TV charging. However I agree with the above statements on the TV charging ability - the alternator is NOT a battery charger as much as a battery recovery and system voltage source.  To really charge the trailer battery you need something like the Victron Orion TR DC-DC charger in line with the 12V out of the trailer. The nice thing with staying with Victron is they all network together to intelligently monitor and control the charging.

JeffroNC

I mounted the Victron Orion in the bed of my truck and ran 8ga wire to the battery. From there, I put a heavy duty connector on my bumper. I added a pigtail from the junction box on the Tab to plug into my truck. I get 12 to 18 amps into my lithiums when the engine is running.
Yes, there is voltage drop between the controller and Tab battery. I plan to correct that by running new wiring through the trailer to the battery and moving the Orion back to the battery. 

jbajor

That sounds like an outstanding setup!  Due note below solar output is the battery voltage.