Gary Hatt
September 25, 2022

My Batteries Were Dead But This Time Knew

I was out to lunch when my email pinged me and I also received this text message on my phone.

This is an automated RV Whisper alert from BCM Bus: 

The Alert named Start Battery Voltage too LOW was triggered on June 13, 2022, at 2:03 p.m. Start Battery Voltage: DC Voltage (Volts) = 11.59

To see details about the alert or to stop these emails temporarily or permanently go to (my Alert settings)  Alert created 1 min ago.

I was in Fairplay, Colorado having lunch with a friend when I was notified via text message of a problem in my bus. I read the text message and immediately knew what the problem was.  

When I stopped driving the bus that morning, I parked at a truck stop, put the transmission in neutral, set the parking brake, and turned the ignition key off; but forgot the last step. I forgot to turn off my headlights. 

Back in 1967 when my bus was built, the headlights did not turn off automatically when the ignition key was turned off and there was no buzzer to alert you of such when you open the door as there are on many vehicles now.

After I backed into my parking space at a truck stop with my toad (yes, you can back up with a toad, if you are backing up relatively straight and if you have a Roadmaster Towbar as I do) I turned off the ignition key, got out of my driver’s seat, and pushed the Search button to make my roof-mounted satellite dish crank up and seek the necessary satellites. I could hear it whirring away. 

I went outside to do a walk-around to be sure I was parked in a safe spot and to turn the key off in my toad.  (I have to leave the toad key on to allow the steering wheel to turn).  I turned my toad ignition key off, locked the doors, and went back inside my bus to work on the magazine.

I was working on the August issue of BCM on my laptop in my bus while I was waiting for a friend to arrive, as we had lunch plans that day.  A couple of hours later she arrived and we went to lunch.  We were just finishing lunch when I got the above text message.  I checked my message and said, “Oh Shoot” (or something like that). 

We finished lunch and when I got back to my bus about an hour later, I looked at my BatMon (Battery Monitor) gauge on my dash that I mentioned in my previous article about this system (I Didn’t Know My Batteries Were Dead) and by now it was showing 8.4V.  Not good.

My LED headlights were out by then, or at least so dim that I did not notice if they were on in the daylight when we drove up, but I knew my bus would not start. I immediately turned off my headlights.

I didn’t have any friends around to help push start my bus, as explained in How to Push Start a Bus,  so I had to resort to Plan B.

I started my Wrico generator.  Because I have a separate battery for my generator (as you should too) and the generator started right up.  I also have a NOCO battery charger/maintainer plugged into an AC power outlet in my start battery bay, so my start batteries immediately started charging as was verified on my BatMon display.  It took almost an hour to bring my batteries up to sufficient power for my bus to start.

I then started my bus and let it run for a few minutes and then shut it down.  Everything was fine, as I had decided to stay there for the remainder of the day and leave at daylight the next morning.

However, had I wanted to leave immediately upon returning from lunch, I would have been up Ship’s Creek.  I would have had to wait at least an hour before my batteries would charge up enough for my bus to start to be able to leave.  If I had come back to a note on my windshield that said “Please move this bus immediately.”, I would have been in trouble and may have even been saddled with a huge tow bill. 

This is what the RV Whisper App looks like on my phone when everything is normal. Alerts are set
up to notify me by email and via a text message if anything goes beyond the specifications I defined
when setting up the system.

It could have been worse.  Had I not had the Whisper monitor/alert system, I may have never noticed that I left my headlights on when I returned to my bus after lunch. I would have spent the remainder of the day going along my merry way, proofreading magazine articles, etc. 

I would have gone to bed not knowing that my batteries spent the past several hours slowly trickling down to practically nothing.  And as everyone knows, lead-acid batteries that drain down too low, have their lifespan significantly reduced.

I would have awoken the next morning before daylight, lowered my satellite antenna, checked my oil and coolant levels in my bus, packed everything away, put the key in my toad and turned on the ignition to unlock the steering wheel, done my walkaround, then put everything away inside of my bus to get ready to travel.

After doing a final check just as the sun was just beginning to come up, my favorite time to drive, I would have turned on the ignition key, and I would have heard dead silence.  I would have probably mumbled something such as “DRAT!”.

By then, I may not have remembered that I left the headlights on, so I would have looked at my BatMon and seen a blank screen, an indication that the voltage was too low to even register, and wondered what went wrong.

I may or may not have discovered the problem immediately, but I would have started my generator, and waited by then, maybe two hours or more until my three Group 31 batteries had enough power in them to start the Series 60 engine.  It was quite cold that morning too, so the starter would have had to work extra hard, requiring extra current to start the engine.

The bus would have eventually started, but by then, I would have missed the best part of the day to drive. When the sun is just rising, it is cool outside, there is very little traffic on the road, and the deer are out beside the road foraging.

When I was ready to leave, I would have reached over to turn my headlights on, as I always do before driving, and I would have then realized that the light switch was left on from the previous day.  Mystery solved, but by then, it was too late to matter. 

So, as you can see, by having an RV Whisper monitoring system in my bus, I was alerted as soon as my battery voltage fell below a preset limit. I preset the system to alert me if and when the voltage dropped below 12.1V.  I reason that it should never get this low, and if it does, something is amiss. 

The RV Whisper system can save you a lot of headaches and embarrassing moments.  Say, for example, you are traveling with a group of other Bus Nuts and they want to get an early start one day to head to their next destination.  You try to start your bus and it does not start.  

If you are lucky and have a generator onboard and a charger built into your system as I do, you can start charging your batteries immediately. However, unless you have a super-charger, which very few people carry in a bus, it could take you several hours, depending on the charger you have, to charge your batteries sufficient enough to start your engine.

You may get lucky and be able to find a friend that can jump-start your bus off their bus, but buses are notoriously large, and maneuvering them around to get them close enough to your bus battery compartment such that jumper cables will reach, is not always an option, especially in an RV Park.

Or say you are parked in a nice quiet spot, but as happened to me a couple of weeks ago, just when I was falling asleep one night at about 10:00, a knock came on my door.  A nice gentleman told me that I could not stay in that parking lot overnight. I apologized and said I did not realize this, there we no signs, so I politely moved to another location that he suggested just down the road. 

Had I left my headlights on when I parked that day, I would have not been able to immediately move, and I may have received another knock on my door, sometime later, maybe this time by a nice person in a blue uniform.

With RV Whisper, I can also monitor the inside temperature of my bus so if it gets too hot, I can come back and start my A/C unit.  Or if my bays get too cold it could freeze my water lines. I can return and turn on some heat in that bay before any damage is done.  

I can also monitor the temperature in my freezer, so if for some reason my freezer/refrigerator stops working, which can happen if my house batteries get too low, it lets me know so I can address the problem before my beer gets too warm and my food spoils.

Therefore, by having the RV Whisper system in your bus, even if you are away, you will be notified if some preset parameter on the RV Whisper system is out of range if, for example, your start voltage drops below your preset voltage if and when you leave something turned on longer than it should be for the threshold voltage required to start your bus is too low.

For more information about this system and other sensors they offer, go to 

Article written by Gary Hatt

Since July 2012, Gary Hatt has been the Publisher of Bus Conversion Magazine. Gary does most of his own work on his bus with the help of mechanic friends. He has owned tents, truck campers, travel trailers, and stick-n-staple motor-homes until he bought his first bus in 1997 which was a 1972 MCI MC-7 Combo. When he had a chance to buy a 1983 MCI MC-9 Log Cabin bus with larger windows he jumped at the chance. On Thanksgiving of 2014, Gary bought a 1967 Model 08 Eagle and has since been living and traveling full time in that.

You may reach Gary Hatt at

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