Low Coach Batteries and the Generator

We have experienced something of interest twice when attempting to exercise the generator for its two hour monthly exercise that has occurred when the coach batteries have been low. By low, I mean the battery monitor on the all reads two LEDs from the bottom - which on the panel is labeled "F" for "Fair Charge".

Here is what happened when I last went to exercise the generator. Whenever I start the generator I start the van engine to give a little extra boost to the generator starter. I started the engine and then went over to the wall monitor panel and Battery Switch and turned on that switch. I next pressed the Test button on the monitor panel to check the batteries - two LEDs up from the bottom. These are the two red LEDs.  I then pushed the generator start button, which in my Roadtrek 190 is just adjacent to the left of the monitor panel, and the generator started to rumble to start. On this occasion, which was after very cold temperatures and snow and ice just a week before, it took three tries to get the generator started. Each time until the third try, when I took my finger off of the generator button, after leaving it down on the button for a short while, the generator stopped. On the third try, it started. This is not unusual especially if the temperatures are cold and the generator has not been run for a time - and the generator this time had not been run for a month. Once the generator has started and is running I turn off the van's ignition. After the generator starts, I always let it run for at least three minutes before I put any load on it. I pressed the monitor panel test button and the battery monitor was up at the top to the green LED "C" or Charging led.  Good. The batteries were charging. The generator was running. The van engine was off. All was well - or so I thought.

To exercise the generator in the warm months, I use the air conditioner to put a load on the generator. It is recommended that at least a half load be applied when exercising the generator and with my Onan 2800 watt generator, the air conditioner is a good half load. When it is cold, I use an electric house heater plugged into a wall outlet inside the Roadtrek. Most electric heaters are 1200 to 1500 watts and this is also a good half load appliance to exercise the generator.

Usually - with the coach batteries showing three LEDs up from the bottom - up to the yellow LED labeled "G" for "Good Charge" - once plugged in with the generator running, the heater starts when turned on - fan and temperature control up to high for maximum load. This time the heater started as expected. When a load goes on the generator the sound of the generator changes - which it always does. All is still well I thought. I pushed the test button on the monitor panel and the battery level still showed all the way to the top green LED. Good. The heater was running. Good. And then the heater shut down. No power in the heater. The generator was still running. I pressed the Test button on the monitor panel and the green LED was flashing and then it went off. I tried to turn on the heater again, and it would not start - still no power (or not enough power). This has happened before - and with a different heater and once with the air conditioner. The heater worked fine inside the house. It was not the heater. The generator sound started to change to the sound it makes with no load (a higher pitched sound). I pressed the test button again and the battery level was back up to the C charge green LED.

I tried a few more times to turn the electric heater on. It would start, the generator sound would change - lower rumble sound - and then after a few moments the heater would cut off again - and again the LED battery panel with the Test button pressed showed a flashing charge LED which would then go out to the G yellow LED indicating that the batteries were not being charged with the generator running. I gave up at that point trying to run the heater. I just let the generator run so that it would charge the coach batteries. At that the monitor panel showed Charging and I let the generator run for its two hours just that way. The batteries did charge.

So, it is important to know that this can happen if your batteries are low when you run the generator. One would think that if the generator is running, once started, even with out any power in the batteries it would just keep running and delivery its 2800 watts. This is not the case. If the batteries are low in the way that the Roadtrek is wired from the generator to the Tripp-Lite inverter/converter/charger which controls all electricity through the Roadtrek regardless of the source, the generator will deliver its power to charge the batteries before it will deliver enough power to the outlets and appliances to run them. While this is just an inconvenience during a generator exercise, if you were in need of 110v power inside the Roadtrek while out, you would not have it - until you get the batteries up to charge. All the more reason to make sure your coach battery or batteries (depending on Roadtrek model) are kept charged.

What can you do if this happens and you are in real need? One thing you can do is drive the van. Two hours of driving will bring the coach batteries up to full charge. If you can't drive, then just run the engine - with nothing using electric power being used inside the RV. According to the author of the Roadtrek Electric Simulator in his Notes file, the engine if run for a half hour even at idle will give enough of a charge into the coach battery(ies) to bring them up - not to full charge but enough.

Good to know and to keep in mind. And as the Hitchhiker's Guide to the Galaxy says on its cover, "Don't Panic!" Something I have to keep reminding myself when things go wrong. (Usually, it takes Meryl to remind me this.) And as the singer, Meat Loaf says in a very little known movie that he was in a long time ago playing a rock band roadie, "Everything works if you let it!"

Questions from Readers - Important To Know About the Inverter

Here is another question from one of our readers. In the process of answering this question I learned something new (to me) and it is something that is very important to share.

Here is the question emailed to us -

" If you are not hooked up to  any external power, and not running the generator, and your battery switch off, but the inverter switch is on, will you have AC power at the inverter outlets? I do, and for the first time ever that I can remember, the battery was on low just today. A big surprise to me!!"

When I read this question I began to write that this had to be something wrong. If the battery switch is OFF how could there be 12 volt power to invert to 110 volts into the outlets connected to the inverter? I proceeded to write an answer about all of the things that could be wrong. I also went into an explanation of what the inverter wall switch is and does (which I will include here in this article). Then I decided before I sent off my answer to go to the Roadtrek Electric Simulator and do a simulation test of what happened in the Roadtrek that initiated this question. I tried it with two Roadtrek year's models. The first simulation was done for a 2010 Roadtrek 190 - with the Tripp-Lite 750 watt inverter/converter/charger all in one unit. The second simulation was done for a 2004 Roadtrek 190 - with no Tripp Lite but a separate inverter unit and a separate converter/charger unit. The third and last simulation was done for a 2010 Roadtrek Sprinter - which has a different Tripp-Lite all in one.

The results that I found surprised me. With the BATTERY SWITCH OFF and the INVERTER WALL SWITCH ON - and no other power sources such as generator of shore power, THERE IS 110 volt POWER IN THE INVERTER CONNECTED OUTLETS for both the 2010 Roadtreks - both the 190 and the Sprinters. (The 2010 models are the last models represented in the simulator but with the 190 models up to 2013 and maybe 2014 the wiring and components are the same (providing none of the new ETrek like electric components have been installed.) The Sprinters without ETrek components are the same as well. They contain a Tripp-Lite all on one inverter/converter/charger.

The 2004 Roadtrek 190 simulation found what would be expected - with the Battery Switch OFF and the Inverter Switch ON there is NO POWER in the inverter connected outlets. None of this applies to Roadtreks before 2006.

For the Roadtreks 2006 and after, if you leave the Inverter Wall Switch ON, and the battery switch is OFF you are drawing power from the batteries into the outlets and anything that is connected to those outlets - the TV, the Home Entertainment Center unit is draining your coach battery (ies). To me this is a very bad situation. While most of us have been believing that if the battery switch is OFF there is no 12 volt power coming through, it is coming through the Tripp-Lite and into those outlets.

I have read many comments and questions about the Roadtrek regarding mystery drains on coach batteries. Now we know one more place to check if your batteries are draining. Also be aware that with the Inverter Wall Switch ON even when the Battery Switch is OFF those outlets are LIVE and 110 volts can give quite a jolt! The bottom line is only turn on the Inverter Wall Switch when you want to use the power in the inverted outlets right then. When you are finished using those outlets with the inverter, turn off the inverter wall switch. I know that some keep the Inverter Wall Switch ON when plugged into shore power to take advantage of the Tripp-Lite's power protection functions. If you do this, make sure to turn that Inverter Wall Switch OFF when you unplug from shore power!

I have explained the Inverter Wall Switch in the Roadtrek before but I will explain it here again. The wall switch on the inverter is actually a remote control switch - there are three states of the inverter - Off, Charge Only, Auto/Remote. These three states are found on the switch on the inverter unit itself. That switch on the inverter unit is generally left on the Auto/Remote position. The wall switch remotely controls those last two functions - Auto/Remote = which is the function that includes sending inverter power to the wall outlets - and Charge Only which puts no power in the outlets but allows the inverter's charger function to charge the batteries when running the engine, plugged in, or running the generator. With the wall switch ON you are in Auto/Remote function. With the wall switch Off you are in Charge Only function. Tripp Lite has its own remote control panel with more functions and indicators, but Roadtrek made its own  switch and attached it to the remote port on the inverter unit (the port looks like a network cable connection and uses the same type of plug and wire). The Tripp Lite panel is larger than the Roadtrek switch and is available as an option from Tripp Lite.

If you do not have a Tripp-Lite inverter, test this for yourself with a volt meter and putting the Inverter Wall Switch ON and the Battery Switch OFF and carefully test the outlets connected to the inverter for power.