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!"