Automatic Engine Start Stop Module

[VanFan]

I have a custom built van with 2 alternators charging a 600 amp hour lithium battery. I can run the air conditioner for about 4 hours with this setup before I have to turn on the engine to charge the battery. I'd like to be able to sleep 8 hours without having to get up to turn on the engine in the middle of the night to keep the AC running. So I want to add an automatic engine start-stop module which can be actuated by my Victron monitor when the state of charge is low. Unfortunately it seems every aftermarket engine start stop module has a built-in time limitation (15 to 60 minutes) after which it shuts the engine down. Does anyone know of an aftermarket module that will allow the engine to idle until the battery monitor sends a second pulse when the battery is fully charged? Or does anyone know who makes the start-stop modules used by Roadtrek or Winnebago or Advanced RV?

[BBQ]

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The Roadtrek Voltstart has a 35 min limit.

The Winnebago Autostart has a 60 min limit.

[cruising7388]

Originally Posted by VanFan

Unfortunately it seems every aftermarket engine start stop module has a built-in time limitation (15 to 60 minutes) after which it shuts the engine down. Does anyone know of an aftermarket module that will allow the engine to idle until the battery monitor sends a second pulse when the battery is fully charged? Or does anyone know who makes the start-stop modules used by Roadtrek or Winnebago or Advanced RV?

The Roadtrek Voltstart sequence is for 35 minutes but it responds to diminishing bsttery voltage and will restart another three or four times before quitting. So technically, it will provide approximately an additional three hours before you would have to address it manually. But I think you would end up being awakened by the engine starting again and again. IMO, the only way you can expect a full 8 hours without uninterrupted sleep is by increasing battery ah capacity to the whereabouts of 1600 ah. AFAIK, Roadtrek is the only class B builder that offers a 1600ah battery option.

I've lost the name of the company that builds the remote starts but if memory serves it is one company that builds different remote start versions for a number of OEMs. From what you indicate, you already have the trigger part of the system already incorporated in the Victron module. The trick will be to find a remote start module that will respond to Victron commands.

[VanFan]

Originally Posted by BBQ

.

The Roadtrek Voltstart has a 35 min limit.

The Winnebago Autostart has a 60 min limit.

Are those the maximum times they let the engine run or the minimum?

[markopolo]

I'd focus my attention on the A/C unit and setup to see if that power consumption can be greatly reduced.

For example: A 5000 BTU A/C unit would draw maybe 50Ah

That won't cool your van in Texas but could it maintain an already cool van overnight? If not 5000 then maybe 8000 or 11,000 btu ...........

You can additionally run the dash A/C to get temperatures under control.

Some roof top A/C units are way more efficient than others.

[VanFan]

Originally Posted by cruising7388

The Roadtrek Voltstart sequence is for 35 minutes but it responds to diminishing bsttery voltage and will restart another three or four times before quitting. So technically, it will provide approximately an additional three hours before you would have to address it manually. But I think you would end up being awakened by the engine starting again and again.

I wonder why their system runs for such a short time. Maybe there's a Federal regulation that limits the run time for automatic start/stop systems.

Originally Posted by cruising7388

IMO, the only way you can expect a full 8 hours without uninterrupted sleep is by increasing battery ah capacity to the whereabouts of 1600 ah.

That would be wonderful. Unfortunately there's no room in our van for a bigger battery, at least not without major "surgery" involving cabinetry, tankage, and so forth.

Originally Posted by cruising7388

From what you indicate, you already have the trigger part of the system already incorporated in the Victron module. The trick will be to find a remote start module that will respond to Victron commands.

Yes, the Victron is made to integrate with generator start/stops. Will send a pulse based on low and high state of charge levels that are user selected, so it's perfect for the job. If I can't find an automotive aftermarket start/stop that plays nice with the van and allows the run time we need, I'm thinking we may try to wire a generator start/stop into the van's ignition system. Just beginning to think my way through all the issues with that. Preferably we would avoid involving the van's on-board computers altogether but not sure if that's possible.

[VanFan]

Originally Posted by markopolo

I'd focus my attention on the A/C unit and setup to see if that power consumption can be greatly reduced.

For example: A 5000 BTU A/C unit would draw maybe 50Ah

That won't cool your van in Texas but could it maintain an already cool van overnight? If not 5000 then maybe 8000 or 11,000 btu ...........

You're right about 5000 btu's not being up to the task down here. Except for the fan noise, I doubt if we'd even notice it was on. Ours is 13,000 and that's the minimum that would be effective. We were already hitting the upper 90's in mid-May, and can expect that to continue until October.

Originally Posted by markopolo

You can additionally run the dash A/C to get temperatures under control.

Of course that would require running the engine all night....

Originally Posted by markopolo

Some roof top A/C units are way more efficient than others.

Back when I designed the van originally, I couldn't find a good 12v AC system with an independent (non engine driven) compressor. I understand there are a couple of good ones out there now, and if I was starting over I'd look hard at those. At the time though, the Coleman Mach 3PS was the most efficient 120v unit available, so that's what we used. And it is efficient, drawing only 85 to 90 amps to produce 13,000 btuh.

[Davydd]

Originally Posted by BBQ

.

The Roadtrek Voltstart has a 35 min limit.

The Winnebago Autostart has a 60 min limit.

Advanced RV is programmable to run up to any time setting up to 1 hour 55 minutes at a time or shuts off when batteries are charged. It is programmable to not start or not start during hours of your choice which is usually campground quiet hours. It is managed through the Silverleaf touch screen.

[avanti]

I think these time limits have multiple motivations. One of them may be a concern for CO accumulation should a vehicle end up deciding to start itself inside an attached garage. There has apparently been a spike of home CO poisonings since keyless start has become a popular feature on high-end cars. I won't be surprised if CO detectors eventually become mandatory on remote-start vehicles.

[VanFan]

Originally Posted by Davydd

Advanced RV is programmable to run up to any time setting up to 1 hour 55 minutes at a time or shuts off when batteries are charged. It is programmable to not start or not start during hours of your choice which is usually campground quiet hours. It is managed through the Silverleaf touch screen.

I believe the Silverleaf system is the monitor, but they don't manufacture equipment such as the start/stop module (the device that relays start and stop pulses or current to the engine starter through the Sprinter's on board computer). Is that correct?

And if so, do you know what kind of start/stop module Advanced RV uses?

EDIT: I found a "PM-002 Total Power Controller" on the Silverleaf website that might be what AdvancedRV is using although Silverleaf only mentions a genset start/stop function. Will call Silverleaf on Monday to see if it can be used with a Victron monitor and the main engine, or if it's only compatible with their monitors and a genset.

[VanFan]

Originally Posted by avanti

I think these time limits have multiple motivations. One of them may be a concern for CO accumulation should a vehicle end up deciding to start itself inside an attached garage. There has apparently been a spike of home CO poisonings since keyless start has become a popular feature on high-end cars. I won't be surprised if CO detectors eventually become mandatory on remote-start vehicles.

I think you're right. Also, the limits are probably there to avoid returning to a vehicle that has accidentally run out of fuel due to an unintended start. But both the garage/CO and unintended start issues apply only to unattended vehicles. Since we will be on board, it seems like we should be allowed to determine how long our engine will idle. Of course, we would never do this in an enclosed space. And we have 5 gallons of fuel in a Jerry can on the rear door in case we forget to monitor the main tank while charging. That's good for a 70 mile drive to the nearest service station.

[cruising7388]

Originally Posted by VanFan

And we have 5 gallons of fuel in a Jerry can on the rear door in case we forget to monitor the main tank while charging. That's good for a 70 mile drive to the nearest service station.

It's seems that every solution that provides a technical advance, concomitantly produces some wrinkle you never had before. With an Onan generator, this is not an issue because the generator feeder tube by design leaves a quarter of the fuel tank capacity intact. Presently with auto start, AFAIK, there is no feature that inhibits it if fuel is low. But I think that before long, this will be addressed by Silverleaf, Victron et al and upbuilders by providing a feature that samples the fuel gauge while autostart is active and permits the owner to program a fuel percentage trigger point for shutting autostart down. For icing on the cake, it could also monitor CO levels to the same effect.

[jon]

With 600 amp hour lithium battery I wouldn't expect to need to idle the van for overnight AC. Outside van has been installing this 13000 btu 12 volt ac so it must work. I would check it out. The specs are for 24 volts so 46 amps for 12 volts is defiantly doable. They have a lot of US dealers:
Kingtec USA

[Davydd]

It is not difficult to anticipate the weather and top off your fuel before stopping. If you do so there should be no way to run out of fuel with the auto start parameters.

[VanFan]

Originally Posted by cruising7388

But I think that before long, this will be addressed by Silverleaf, Victron et al and upbuilders by providing a feature that samples the fuel gauge while autostart is active and permits the owner to program a fuel percentage trigger point for shutting autostart down. For icing on the cake, it could also monitor CO levels to the same effect.

That sure would be nice. Then maybe they'd allow customers to set their own runtime limit, if any. In the meantime, the hard coded runtime is very frustrating.

[Davydd]

Originally Posted by VanFan

That sure would be nice. Then maybe they'd allow customers to set their own runtime limit, if any. In the meantime, the hard coded runtime is very frustrating.

That's exactly what you can do with Advanced RV's Silverleaf controller.

You have to still have common sense. After all many people run out of fuel while driving.

[proeddie]

Or you could back into the solution....

When you go to bed, start the engine and let it run for 4 hours. that will get you to a point where the rest of the night runs on battery power.

A timed engine shutoff should be a lot easier and no sensing is required.

[Storysrvwego]

If the Start/Stop modules you have are not sealed in Expoxy, then have someone change the time constant for you.

If the time interval is set into firmware, then you may not be able to alter it without the proper programmer interface. If it is as simple as external resistor/capacitor loop on a timer chip, then the values can be calculated, and changed to new calculation to extend the time.

Someone really sharp with programming an Arduino micro controller could easily set that up to have relay fed via optical isolation to provide contact closure at the amperage required unless you just need a pulse for x microseconds (or seconds or whatever). Depending on the milli, micro or amp requirement to connect too, there are interfaces for an Arduino that can handle that too. Programming code is fairly simple for an Arduino.

A Rasberry Pi is more of an actual computer and it runs on special version of Linux operating system. Because it is a computer with an actual OS versus an Arduino which is a controller running dedicated task based on simpler firmware coding. Given the single minded nature of the job to be done here, I should think almost any version of an Arduino would work. I am not an expert here; find someone that is well versed and perhaps for not very much money, you can coax them into writing the code if you buy the hardware for him or her to make this for you.

Using an Arduino solution will be simple enough. Powered on, it will await a trigger from low battery situation to do its thing. If it is powered off, then your present manual method of starting up the engine will be back in play.

The firmware needs to have a line in the code for setting the length of time. If the Arduino is powered off, the engine would stop right then if the output driver device is goes to an "open" state for a relay which will relax (disconnect. If the output driver device connects to electronics in the vehicle to start the engine, then an open state output device probably is not the correct choice; the zero-state output would have to be clamped to a high or low state (whatever the engine electronics requires) to insure engine absoluty shuts off when no power to the Arduino or Arduino is powered but firmware instrucs the output driver to change to the state that the engine electronics recognizes as off, kill, key off or whatever term is appropriate.

There might be a mini-market for this. Except MERCEDES, FORD and RAM likely handle ignition on/ignition off differently. Getting to the wiring in the dash or underhood to tap into likely to be a challenge on these newer vehicles. I am sure you can forget about vehicle warranty. Making a mistake, especially on a Sprinter could be costly if dealer help required to fix the van. And you know a dealer service company will disconnect or make you disconnect your circuitry before they do any work on the original equipment.

Just tossing some seeds out.

[cruising7388]

Originally Posted by Storysrvwego

Just tossing some seeds out.

Thanks for your in depth analysis. You clearly know your ****

The duration of the autostart period seems to vary by builder. ARV's autostart permits owner programming while Roadtrek's Voltstart permits no owner programming whatsoever either with the number or the length of the restarts. They make some vague allusion to EPA requirements involved.

There may be some constraints regarding the use of these autostarts in unattended vehicles. There are apparently some localities that don't permit it.

[russ240]

Originally Posted by proeddie

A timed engine shutoff should be a lot easier and no sensing is required.

I have thought about doing just that with a turbo-timer .... but those are typically used to run the engine for a few minutes after you turn the key off. I'm not sure if they provide a setting for 2-4 hours of after run????

I'm sure there is some way to do this with a custom setup, but I would be interested in a more plug and play setup.