A few Qs on our new 5.0TA

[jkordzi]

We picked up our 5.0TA and are hanging out at the Pioneer Trails RV Park in Anacortes, WA for a shake down. Everything is fine and we're learning the systems so I have a few questions I couldn't figure out from my remembrance of the orientation or the manuals.

1. Our trailer has solar with dual 6V batteries. I noticed when I plugged in the power cord that the fan for the inverter was running so I went to the Go Power panel and checked a few things. I made sure that the "B" button was pushed until "Flooded" showed up for the battery. Since we have dual 6V batteries, am I correct that the "A" button has no effect? I also turned off the plug symbol, which shut off the fan, reasoning that this was indicating that the solar panel's electricity was being run through the inverter and this wasn't necessary when plugged in. Is this correct?

2. I initially turned on both the gas and electric power for the hot water heater. After a while I turned off the gas since we're plugged in. The water temp is very hot, so I was wondering how to turn in down a bit?

3. Our tow vehicle is a 2017 GMC Canyon which so far has towed the 5.0TA very well (although we haven't pulled it up the road to the Eisenhower Tunnel). It has an AT&T hotspot through Onstar that we can activate monthly. However, since it draws power, the truck has to be running or the key must be in the "on" position. Since the truck charges the trailer's batteries when plugged in via the 7 pin connector, will the reverse occur - power from the trailer will charge the truck's battery so I can keep my hotspot going? If so, will the trailer's charge controller ramp down the charge so the trailer's batter doesn't get over charged?

BTW, we ordered our 5.0TA w/out a toilet (still have the black tank) and I installed a composting toilet. I'll post a few pics of that in another post.

Thanks.

[cpaharley2008]

!. yes, the fan will operate automatically, when needed, due to use, both on the inverter and converter. Yes you want the flooded battery (dual 6ers are treated as one 12v battery)
2. no way to reduce the water temperature in the water heater except wait until it cools down a bit.
3. the trailer will not back flow to the truck, in fact the truck will continue to pull from the trailer. You will have to leave your truck on acc to use the hotspot in the truck

[santacruzer]

It's my understanding that you shouldn't turn on the inverter when you're attached to shore power, is that correct?

[jkordzi]

Originally Posted by cpaharley2008

!. yes, the fan will operate automatically, when needed, due to use, both on the inverter and converter. Yes you want the flooded battery (dual 6ers are treated as one 12v battery)
2. no way to reduce the water temperature in the water heater except wait until it cools down a bit.
3. the trailer will not back flow to the truck, in fact the truck will continue to pull from the trailer. You will have to leave your truck on acc to use the hotspot in the truck

Thanks. One clarification on No. 3: When you say the "truck will continue to pull from the trailer," Do you mean that whn hooked up to the 7 pin connector, the truck will not draw from its own battery? If so, that's what I was hoping for.

[NW Cat Owner]

Originally Posted by jkordzi

2. I initially turned on both the gas and electric power for the hot water heater. After a while I turned off the gas since we're plugged in. The water temp is very hot, so I was wondering how to turn in down a bit?

BTW, we ordered our 5.0TA w/out a toilet (still have the black tank) and I installed a composting toilet. I'll post a few pics of that in another post.

Add in more cold water!

I've been thinking about changing to a composting toilet and have read a bunch of stuff on them. Are you going to hook the black and grey tanks together? I read a comment somewhere (not on this forum) where someone did that and really extended the time between tank dumpings.

What brand? I was looking at the Nature's one (I think it was) and it seemed to be too wide to get through the door and the mfgr never responded to my questions about it.

So, yeah, start a thread on the composting toilet and update it with how it's working for ya.

[Vermilye]

Originally Posted by jkordzi

Thanks. One clarification on No. 3: When you say the "truck will continue to pull from the trailer," Do you mean that whn hooked up to the 7 pin connector, the truck will not draw from its own battery? If so, that's what I was hoping for.

It depends on the wiring (and whether the truck has an included isolation relay) as to if the truck battery will be charged by the trailer battery/solar panels. In most cases, the trailer will not charge the truck.

As to the inverter being on when connected to shore power, while it won't hurt anything, when the inverter is on, the transfer switch switches the trailer receptacles to the inverter. You will save wear & tear on the inverter (and prevent overloading it) & transfer switch contacts by leaving it off. Even when dry camping, it is better to leave the inverter off except when you need 120V AC. It draws around 1 1/2 amps even without a load, which will eventually draw down your batteries.

[rubicon327]

Originally Posted by jkordzi

2. I initially turned on both the gas and electric power for the hot water heater. After a while I turned off the gas since we're plugged in. The water temp is very hot, so I was wondering how to turn in down a bit?

Nope. Suburban literature states that it is fixed at 130F. It appears the burners don't come back on until the water temp drops below 110F. So the reality is you are somewhere in between most of the time.

[Brian B-P]

Some people install isolation diodes, which would keep the trailer from charging the truck, but that is now unusual and GM would not have used this sort of system.

Without an isolation diode, electrical current could flow either way between the truck and the trailer, from whichever battery has higher voltage to the other. What will determine if it can flow is any isolation relay in the system, including whatever GM may have installed.

With the truck's key in the "on" position, the relay could be turned on: this is to allow the truck to charge the trailer, but if the trailer is plugged in and the truck is not running, the charge would go the other way (to the truck). It is possible that the truck will not turn on the relay unless the engine is actually running and the truck's charging system is producing power: in that case, the truck's battery would not get charged. It's hard to say without having all of the details of the truck's trailer wiring design.

I don't like leaving any vehicle in the "on" state without the engine running (or able to run, in the case of hybrids and stop/start system equipped vehicles) - it's just not how it was designed to work, and I'm never sure if there is something being powered which shouldn't be. If the vehicle's designers intended equipment to run without the engine, it would be connected to an accessory circuit, so the key would only need to be in the "ACC" position. True, the vehicle's designers can make different choices for some of this equipment than we might.

One way to keep power in the truck while parked, given that you are at a campsite with power, is to plug in a small battery charger (or "maintainer") and connect it to the truck, rather than depending on the trailer's charger to do the same thing via the 7-pin connector.