Where is the charge line from the tow vehicle connected on the T@B 400.

Viajero

Hi folks. Just doing some modification planning. Our T@B 400 won’t arrive for another 2 months. 

The 12 volt charge line (1 o’clock position on the 7 pin connector) from the tow vehicle connects somewhere inside the T@B 400 and my guess is that it is either on the back of the converter or possibly right on the battery itself. Can someone tell me if they have found it, what gauge it is and exactly where it connects?  

Thanks in advance. 

John. 

Horigan

The 7 pin connector connects to a junction box under the front of the trailer behind and below the front tub.  From there the wiring goes to the battery positive terminal.  I don't recall the gauge, but it's thinner that 10AWG.

qhumberd

Using a shunt to measure on our 400 the 7 pin on our tow vehicle supplies about 2 amps current along the line to the battery when the TV is running. Our TV has a disconnect so the charging system and battery on the TV are disconnected when the vehicle is turned off. For such a long run this is not too bad. When towing our biggest load is the 2 way frig which pulls around 4- 5 amps when it cycles on. It varies but seems to run about 15 min out of each hour. The TV can then keep the battery at full or nearly full but it can't recharge the battery much while we are traveling. That would be an advantage of solar panels.

Viajero

Thanks for the info guys. We are using a Tesla model Y for a tow vehicle but the charge line voltage is a little less than I like for AGM’s. I’m going to use a Victron 9 amp DC to DC converter to get the voltage to a more suitable charging voltage. 

Cheers. 

qhumberd

Cool. You will have to report on EV towing when you get all hooked up. Interested to see if an EV can perform better near its towing limit compared to an internal combustion engine (ICE)

Viajero

qhumberd said:

Cool. You will have to report on EV towing when you get all hooked up. Interested to see if an EV can perform better near its towing limit compared to an internal combustion engine (ICE)

Yah for sure. It’s getting fairly common around here as Tesla model Y’s are pretty common. Power is not an issue as most people towing get the AB option so they have around 450 horsepower. Braking with regenerative braking saves the brakes and even on steeper hills it’s rare to have to use the service brakes. Having a frunk (front trunk) allows for loading heavier things over the front axle  which compensates for the tongue weight pivoting weight off the front axle.  It’s the future for sure. 

Cheers 

N7SHG_Ham

I will be following your experience, personally, a MY for a TV with a 400 is going to be close to limits at least on paper. "The hitch on the Model Y is rated to tow a maximum of 3,500 pounds, with a maximum tongue weight of 350 pounds. The maximum vertical accessory weight, for bike racks and the like, is 160 pounds."

You will really have to be careful with that 350 hitch weight, and the 160 vertical rating is concerning too, not even sure why they have that along with a hitch weight rating.

From what I have read, even towing a 1000 pound small trailer with essentially no frontal area like a 400 has results in about 200 miles range. With a 400 that will surely be reduced further.

I hope it works out for you, but I think the MY is going to be stressed with the weight and the range is going to be severely limited, especially considering unless there is at least a level 2 charger at or near the CG, you will really only have 50-100 mile range one way since you need to get back home too.

Viajero

N7SHG_Ham said:

I will be following your experience, personally, a MY for a TV with a 400 is going to be close to limits at least on paper. "The hitch on the Model Y is rated to tow a maximum of 3,500 pounds, with a maximum tongue weight of 350 pounds. The maximum vertical accessory weight, for bike racks and the like, is 160 pounds."

You will really have to be careful with that 350 hitch weight, and the 160 vertical rating is concerning too, not even sure why they have that along with a hitch weight rating.

From what I have read, even towing a 1000 pound small trailer with essentially no frontal area like a 400 has results in about 200 miles range. With a 400 that will surely be reduced further.

I hope it works out for you, but I think the MY is going to be stressed with the weight and the range is going to be severely limited, especially considering unless there is at least a level 2 charger at or near the CG, you will really only have 50-100 mile range one way since you need to get back home too.

Yah all good points. But there are quite a few people towing the 400 with the Y up here and we have talked to a bunch of them. All are happy with the combo. We are experienced campers and have towed a lot. 

There are so many amazing campgrounds within a couple hundred kilometres from here. And DC fast charging is getting pretty common everywhere. As well, many of our favourite spots are serviced sites so power for recharging is not a problem. I wouldn’t recommend this combo for those travelling long distances at speeds of American interstates but in the BC interior it’s actually fine. Speed limits are low and tons of little towns.  

The reality is most gas CUV’s and small SUV’s don’t have great range when towing. Small tanks and crappy mileage. Our Jeep Grand Cherokee was horrible for mileage when towing. And you can’t charge it up at the campsite.  

Our friends with the same Tesla/400 combo plan around 220 kilometres of range and they always have a little buffer. It’s been more than adequate for them. They are on the road every Friday at 5:30 and usually setup cookin burgers by 7. Home on sunday afternoon, next Friday rinse and repeat. We are newly retired so our schedule will be a little more relaxed. . 

For us it makes no sense to have a separate tow vehicle as it would just sit in the driveway and depreciate. 

Anyway, thank you for your info and input. Looking forward to making a few mods. 

John.