Espar D2 on starter battery

[chipsterguy]

I have a 2019 4x4 that I’ve recently acquired and had it out fitted including with an Espar D2 heater. My builder wired it on an auxiliary circuit that takes power from the starter battery. This was done for safety reasons as the circuit the heater is wired too will cut out if the van doors are opened for too long (similar to the interior dome/door operated lights). With van doors are open and heater is running, the diesel odor and harmful gasses would get into the van. So the heater cuts out when the dome/door operated lights do. Thats the rationale.

I am OK with this set up. Just dont know how long I can run the heater without starting the van to recharge the main starter battery. Would hate to become stranded when winter camping.

Live in PNW and hope to camp over weekends at the local ski mountains.

Anyone have their heater wired to a circuit connected to the starter battery? Any issues draining the starter battery and not able to start the van?

House battery is not an issue (LiFePO4 300 AH). Starter battery is stock.

Looking for advice and experience from other forum members. TIA

 

[avanti]

Sounds like a bad idea to me.
If you buy the "safety" argument (which I guess makes some sense), a simple relay would let you have that feature while powering from the house battery.

 

[VanGoSki]

What Avanti said, only I'm not as sold on the safety aspect for a few reasons.

1) Your van engine doesn't shut off if the doors are open for too long, and it most likely produces a lot more CO than the Espar.
2) If the van doors are open then the van is a ventilated space. It's generally OK to have fuel-powered heaters running in a ventilated space.
3) If you don't already have one, install a CO detector. It will tell you if you're building up CO and allow you to rectify the situation.

Just as a data point, I just installed my Espar (connected to my house battery) and ran it for about 20 minutes with the sliding door open to break it in. The exhaust pipe for it vents under the van towards the rear of the slider so I fully expected some CO build-up. But my CO detector reported zero the entire time.

Just for reference, this same unit detected CO build-up in the living room of my home from a generator I had running in my side yard. I had the side door of the garage open a crack for the power wire to pass through. Then the wire ran the width of my 2-car garage, and through the door into the laundry room which was also cracked open. The laundry is down a pretty long hallway from the living room. And yet it detected CO that wormed all that way into my living space which surprised the heck out of me. So since the detector is that sensitive and didn't even budge with the Espar running with the sliding door open, I'm not seeing an issue there.

 

[RVBarry]

If the battery is the ED4 factory optional AGM type, it's mixed-duty rated.

 

[mean_in_green]

I use just the starter battery to power my Webasto. I acknowledge that this is not the preferred method but with consideration to power consumption it gets you by. Actually I’m still on the factory supplied battery after over ten years, so “kiss of death” is perhaps stretching it.

 

[autostaretx]

The T1N model years came that way ... if you had an Espar ("auxiliary heater") with the 7-day timer, it was happy as a clam to run from the starter battery for two hours per button-push with the engine off. I ran mine almost continuously one frozen night and was still able to start in the morning.

--dick

 

[mean_in_green]

I’m also running a Dometic CFX fridge in addition to the Webasto, both from the 100Ah starter battery.

During the day the fridge is left on, engine running or not but for an overnight park in say the last hour or so of driving I’ll drop the fridge temperature from zero down to minus ten celsius then turn the fridge off. It doesn’t generally warm up above five degrees by morning, and I don’t turn it back on until after I’ve started driving again.

If the ambient temperature is chilly I’ll start the night heater before turning the engine off for the night, as it draws it’s maximum current during start up. Once it’s warmed up and running the current draw drops off a lot becoming fairly modest, then I switch the engine off. I found fitting the external temperature sensor made a noticeable difference in how well the unit regulates (“external” being a slight misnomer - i.e. external to the heater unit but still inside the cab).

Out of curiosity I once ran a spare 100Ah battery to the death using the fridge. It went four days. The Webastos / Eberspachers do use a bit more juice but I’ve never not been able to start the engine the following morning after using one all night, even in minus thirty celsius ambient.

As I said, I appreciate that starter batteries are really not designed for it and an auxiliary battery set up is sensible. We will have differences in the ways we all use our Sprinters however part of the reason I’ve never got around to it is simply that I initially neglected to order it from the factory but subsequently found that I’ve not actually needed to retrofit. I no longer even drag a spare battery around with me, just some proper jump leads and an AA card (neither of which have been used to date...).

 

[wquek]

The Espars are not designed to have power cut out when running. Before it actually shuts down, the fan operates for a few minutes to cool down the unit. If you turn the power off while it is running and still hot, you will find yourself with a dead heater from carbon buildup. Get the CO sensor.

 

[chipsterguy]

FYI for those who are curious...

I have determined that terminal 2 of EK1 (30T) is controlled by the Body Control (BC) module and switchable (refer to 8..4.13 of the upfitter guide for the 907 VS30 vans). If quiescent current is detected on this terminal when the vehicle is powered off and at a stand still, the power gets switched off by the BC after a certain amount of time (I observed 45 minutes.)

Recall from earlier posts that my builder tapped into this terminal 2 (starter battery) to power the Espar D2 heater. I observed that I could only run the heater (with doors closed) for 45 minutes before power would cut out. If you opened and closed the doors to the van within those 45 minutes, the timer would reset for another 45 minutes. I've confirmed that the Body Control module monitors current draw on terminal 2 of EK1 to prevent the battery from draining.

According to 8.4.13 of the upfitter guide, this does not appear to be the case with the previous generation van (906). For the 906, this terminal 2 is not switchable and would remain connected to the starter battery without interruption. Seems this was changed for the 907s to a switchable starter battery connection.

Note that I have installed Mid City Engineerings 907 RAD-ON module on my van. This was installed for the purpose of keeping the MBUX on when the van was powered down.

907RAD-ON Automatic Radio Shutdown Bypass Module for 2019-2024 Sprinter | Mid City Engineering Store

www.midcityengineering.com

When powered on, this device signals via the CAN bus to trick the van into thinking that the vehicle ignition is position 1 (accessory), having the effect of preventing the Body Controller from cutting off the power to terminal 2. When I have the RAD-ON engaged, not only will my MBUX remain powered (to run van wifi), but the power to the Espar will also remain on indefinitely.

I do plan to change the wiring of my Espar to my house battery (300AH Relion LiFePO4). Connected to the house battery, I will never have to worry about depleting the Starter battery when heating the van during winter camping.

 

[autostaretx]

Thanks for that ... i'll annotate my VS30 EK1 photo to warn folks...
--dick

 

[JohnnyYukon]

So why does the D2 have to have the exhaust ported to the side of the van but the fuel-fired booster factory option has the exhaust right under the main body below the drivers seat?

 

[VanGoSki]

So why does the D2 have to have the exhaust ported to the side of the van but the fuel-fired booster factory option has the exhaust right under the main body below the drivers seat?

Where are you getting that the D2 has to have the exhaust ported to the side of the van? In the install instructions for both the D2 and D5, there's this:

• The exhaust outlet must end in the open air.
• The exhaust pipe must not protrude beyond the lateral limits of the vehicle.

It seems to me those folks who have the pipe sticking out from under the vehicle are violating the second rule.

I suppose one could argue the meaning of open-air. My feeling is that ending the exhaust under the van is open-air and apparently MB does as well. So that's what I did.

 

[OrioN]

So why does the D2 have to have the exhaust ported to the side of the van but the fuel-fired booster factory option has the exhaust right under the main body below the drivers seat?

There is no rule stating that the exhaust must be ported out the side. It is all out in the open air after-all......

....however, there could be an assumption or argument that the MB factory unit is operating when the vehicle is moving predominately.

 

[JohnnyYukon]

Hmm, I read the first line (The exhaust pipe must end in the open air.) as meaning not tucked up into the under-carriage but on re-reading it just now, you both are correct.

On general principle, I am a little worried about accidentally gassing myself with some unplanned for ingress point for exhaust if it was right under the van? I have it near, but not beyond the edge of the van, below the B-pillar.

So, where did folks on here locate the end of their Espar exhausts?

 

[chipsterguy]

Just keep air circulating via maxxair fan, windows, etc. CO detector for safe measure...

 

[Wreckingcrewsdad]

Might wanna contact https://sprinter-source.com/forums/index.php?threads/83087/post-849635
There was reports of units cutting out on stater battery.