Battery. Monitor
- Thread starter denny2010
- Start date
Diane and I set our generator to come on automatically when battery voltage reaches 11.0 volts. This is a compromise between us. I would prefer to go lower to minimize generator hours. She would prefer higher to leave a perceived margin of safety and make it less likely that the truck will not start one day. (We're the same way with fuel. At 1/4 tank, she wants to fill up. I'm content to drive more.)
We have a big sleeper with a large refrigerator and at least one computer on almost all the time, and often two computers on. We sleep with the parking and chicken lights turned on most nights. An electric water pump gets used whenever we want to get a drink or wash up. The Qualcomm unit is on most of the time, as is the data logger for the reefer. If the generator us not being used for heat or air conditioning, the Fan-Tastic Vent (ceiling fan) is usually on. Such is the "hotel" drain in our truck.
There are five batteries on this truck. One is for the reefer. It is isolated from the rest of the truck. It serves and is charged by the reefer only. The other four batteries are the truck batteries. The sleeper, inverter and generator are tied into them. There is no hotel battery or battery bank.
When the truck runs, the truck alternator charges the batteries. When the truck is plugged into shore power, shore power charges the batteries. When the generator is running (like all day and night so we can run the air conditioning), the generator charges the batteries. If nothing is running and the battery voltage drops below 11 volts, the generator automatically kicks in to charge the batteries and automatically turns off when the batteries are charged.
The 11 volt setting seems not to have hurt us any. We purchased four Optima, yellow top, 900 cold cranking amp, batteries in July, 2009. Three years later they are still going strong.
There was an immediate and noticeable difference when they were installed. With the old batteries, the generator used to kick in around 5:00 a.m. to charge the batteries on a typical layover night. With the Optima batteries the generator does not kick in at all on a typical layover night.
Our truck is wired such that the generator must be run to run the microwave. That is because our microwave is a convection microwave that requires a lot of power if convection cooking is being done. Long before the generator would kick in to charge the batteries, we will start the generator to cook breakfast or start the truck to drive somewhere.
It has happened that we forgot to set the generator to "auto-on" and left the truck unattended. From that, we know that if the voltage drops below 10.1 volts, there is not enough power to start the generator (or the truck). The fix is to use jumper cables and the reefer battery to start the generator and then use the generator to charge up the truck batteries. It takes less than thirty minutes for the generator to charge the Optima batteries up to the level where we can start the truck.
We have a big sleeper with a large refrigerator and at least one computer on almost all the time, and often two computers on. We sleep with the parking and chicken lights turned on most nights. An electric water pump gets used whenever we want to get a drink or wash up. The Qualcomm unit is on most of the time, as is the data logger for the reefer. If the generator us not being used for heat or air conditioning, the Fan-Tastic Vent (ceiling fan) is usually on. Such is the "hotel" drain in our truck.
There are five batteries on this truck. One is for the reefer. It is isolated from the rest of the truck. It serves and is charged by the reefer only. The other four batteries are the truck batteries. The sleeper, inverter and generator are tied into them. There is no hotel battery or battery bank.
When the truck runs, the truck alternator charges the batteries. When the truck is plugged into shore power, shore power charges the batteries. When the generator is running (like all day and night so we can run the air conditioning), the generator charges the batteries. If nothing is running and the battery voltage drops below 11 volts, the generator automatically kicks in to charge the batteries and automatically turns off when the batteries are charged.
The 11 volt setting seems not to have hurt us any. We purchased four Optima, yellow top, 900 cold cranking amp, batteries in July, 2009. Three years later they are still going strong.
There was an immediate and noticeable difference when they were installed. With the old batteries, the generator used to kick in around 5:00 a.m. to charge the batteries on a typical layover night. With the Optima batteries the generator does not kick in at all on a typical layover night.
Our truck is wired such that the generator must be run to run the microwave. That is because our microwave is a convection microwave that requires a lot of power if convection cooking is being done. Long before the generator would kick in to charge the batteries, we will start the generator to cook breakfast or start the truck to drive somewhere.
It has happened that we forgot to set the generator to "auto-on" and left the truck unattended. From that, we know that if the voltage drops below 10.1 volts, there is not enough power to start the generator (or the truck). The fix is to use jumper cables and the reefer battery to start the generator and then use the generator to charge up the truck batteries. It takes less than thirty minutes for the generator to charge the Optima batteries up to the level where we can start the truck.
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zorry
Veteran Expediter
Phil,is your Onan set up so that you must set it everytime you want it to be on autostart ? i.e. you cannot set autostart and have it stay on autostart for weeks as you continue your normal work functions ?
Will your roof air cycle on and off automatically at a set temp or must you turn it on and off manually ?
If it's automatic,which unit is it ?
Will your roof air cycle on and off automatically at a set temp or must you turn it on and off manually ?
If it's automatic,which unit is it ?
Yes.
It will cycle on and off automatically at a set temp. Fan-Tastic Vent model is unknown. The unit is not marked. The owner's manual I have is for models 2000RDM, 2000DM, 2000TR and 2000T. It will be one of those but I am unsure which. A Honewell thermostat on the wall is used to set the temp at which the fan vent will open and close.
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zorry
Veteran Expediter
Phil,I never thought I'd have this thought but I may become your little hero.
I was dissapointed that the autostart feature of the Onan kicks off when it gets ignition power.
I believe I have a solution for that using genuine Onan parts. If they were in stock mine would've been done this week for under $250.
Once I get mine done,and I know it works,I'll share the part numbers and sources.
Don't try this at home,the parts needed are not available to the general public.
On the temp autostart I was asking about the A/C unit.
I was dissapointed that the autostart feature of the Onan kicks off when it gets ignition power.
I believe I have a solution for that using genuine Onan parts. If they were in stock mine would've been done this week for under $250.
Once I get mine done,and I know it works,I'll share the part numbers and sources.
Don't try this at home,the parts needed are not available to the general public.
On the temp autostart I was asking about the A/C unit.
It will be interesting to read of your solution, but I doubt Diane and I would spend the $250 because there is no problem to solve.
Human error was the cause of the auto-on feature not being turned on. There was nothing wrong with the equipment. The fix was easy as described above. We try not to repeat our mistakes, and even if we did, the fix would again be easy. This is not $250 that we see a need to spend. The cost exceeds the benefit.
ChanceMaster
Expert Expediter
I wonder if you are trying to run the apu , while going down the road ? I would like to run the a/c feature of our apu (tk trial-) while the truck is running. My co driver doesn't like ac, and runs with the window down @ 65 mph. It's a huge blast of 90 degree air entering the cabin. VERY uncomfortable for this Michigan boy. If I could run the a/c in the bunk , while he enjoys his blast furnace...things would be better.
Sent from my PC36100 using EO Forums
Couldn't you run the bunk AC on cold and he could set the cabin AC to a warmer temp and turn the fan all the way down?
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When set to manual, the generator can be run while the truck is being driven down the road.
ChanceMaster
Expert Expediter
The bunk a/c is vastly underpowered...just a small vent @ my feet. Couple that with the hot air entering the cab, and well...
The tripac a/c is much more effective, but can only use when the engine is off.
Was in tx/la yesterday...it was stifling in bunk area while I was supposed to be sleeping.
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zorry
Veteran Expediter
It'd be worth $250 to me to have a fully automatic APU.
On our Rigmaster we set it to Autostart battery and were good till next time the batteries were disconnected.
I drove an owners truck where we had to start the reefer to jump the APU to start the truck.
Sometimes we haul hot freight: I prefer to turn the key and go. That's worth $250 to me, others I know,and my batteries.
On our Rigmaster we set it to Autostart battery and were good till next time the batteries were disconnected.
I drove an owners truck where we had to start the reefer to jump the APU to start the truck.
Sometimes we haul hot freight: I prefer to turn the key and go. That's worth $250 to me, others I know,and my batteries.
Then for you, it will be $250 well spent.
Onan explains the safety reasons for setting its generators up the way it does. Many scenarios can be invented to support the case. In every case, the human error risk falls on the other side of the setting.
The risk for Diane and me if we forget to set the generator to auto-on is that batteries may discharge if the truck is left unattended long enough.
If a truck is set so auto-on is perpetually on, the human-error risk is that auto-on will not be turned off when it should be; like when the truck goes into the shop for service and is left indoors overnight, or when the truck might be parked somewhere where running the generator may create a fire hazard.
In both cases, the human error risk exists. And in both cases, diligence is the cure for human error.
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Doggie Daddy
Veteran Expediter
does the truck of a interlock switch, this stop the apu from running when the truck is running