NCV3 - Auxiliary Battery, anyone removed it?

[JayP]

From what I’m reading the Aux battery is connected to nothing and the relay that connects it to the alternator only closes when the ignition is on. The aux battery takes up quite a bit of space in the engine compartment and I would much rather put an air compressor there.
Has anyone removed their auxiliary battery?

John

[ITSNO60]

Originally Posted by JayP

From what I’m reading the Aux battery is connected to nothing and the relay that connects it to the alternator only closes when the ignition is on. The aux battery takes up quite a bit of space in the engine compartment and I would much rather put an air compressor there.
Has anyone removed their auxiliary battery?

John

I haven't heard of anyone removing it but you can relocate it under one of the seats which is where MB put some of them. One of the reasons for the aux battery is in case your main battery dies you can still shift out of park for a tow truck.

[ITSNO60]

On second though you'd better clarify, there are two different auxiliary batteries. Are you referring to the tiny 1.3ah battery similar in size to a home alarm system battery or is it a full size automotive type battery?

[StogieMan]

I replaced ours under the hood last year along with the one under the drivers seat on the recommendation of our service manager at Mercedes. Pretty upfront guy and hasn't led me to believe otherwise with his other recommendations. He said "Airstream orders these vans with the auxiliary battery and we don't know what they tie into or what it powers." So I did just that just "in case."

I tried to research it and the only thing that I found that was left on when everything was shut down were the two 12 volts outlets. One under the drivers seat and the other below the the cup holders and this is on the NCV3's.

I was going to do just that and add an air compressor there but it wouldn't fit because of the auxiliary battery. I was going to build a bracket for it as I tried to find some already made ones for it and I could only find the VanCompass ones but require the battery to be removed. I did find a YouTube video on a guy that made a custom one for it with the battery. At this point, I'm scratching that option as we'll be selling ours at some point in the fall.


Van Compass Mount:
https://vancompass.com/products/2007...r-system-mount


YouTube video of Custom Mount:

https://www.youtube.com/watch?v=bAaPuZlOS5Q

Here is some more info:
https://www.airforums.com/forums/f24...ry-238712.html

[Rocinante]

I'd love to add an air compressor under the hood like that, and we do not have an auxiliary battery in there. However given just how hot it gets under there with that little diesel engine, is there a risk the heat would bake and ruin the compressor and any air hoses?

[StogieMan]

Originally Posted by Rocinante

I'd love to add an air compressor under the hood like that, and we do not have an auxiliary battery in there. However given just how hot it gets under there with that little diesel engine, is there a risk the heat would bake and ruin the compressor and any air hoses?

I think that you should be good. A lot of folks do it and I haven't seen any videos or reading any issues with this setup. I've seen setup on both sides of the hood. I believe Wachuko has set this up on his and maybe he can chime in.

[JayP]

Originally Posted by ITSNO60

On second thought you'd better clarify, there are two different auxiliary batteries. Are you referring to the tiny 1.3ah battery similar in size to a home alarm system battery or is it a full size automotive type battery?

I’m not familiar with a 1.3ah battery, I am referring to the H8 automotive size battery under the hood. I will be changing out my original starting battery (same exact size) and am trying to decide whether or not to buy 2. If it is only charging a couple 12VDC outlets I can surely do without it.
It may also be beneficial to use the wiring for the battery on the eventual air compressor.

[ITSNO60]

Originally Posted by JayP

I’m not familiar with a 1.3ah battery, I am referring to the H8 automotive size battery under the hood. I will be changing out my original starting battery (same exact size) and am trying to decide whether or not to buy 2. If it is only charging a couple 12VDC outlets I can surely do without it.
It may also be beneficial to use the wiring for the battery on the eventual air compressor.

I would just disconnect it and wrap the cable ends and drive it for a few days and see if you miss anything.

[JayP]

Originally Posted by ITSNO60

I would just disconnect it and wrap the cable ends and drive it for a few days and see if you miss anything.

Great Idea, and test performed a few minutes ago. No voltage going to the outlet under the seat or the one under the drink tray with the van off. However with the van running I get 14.2 VDC at both places which I was thinking would happen. Since we only use those outlets for phone or hotspot charging while driving I have no worries about not replacing the Aux battery. This will leave plenty of room for some sort of hardwired and switched air compressor.
Not worried at all about starting with a dead starter battery as I have more than enough coach batteries which can be brought in using the momentary assist button.

John

[ITSNO60]

Originally Posted by JayP

Great Idea, and test performed a few minutes ago. No voltage going to the outlet under the seat or the one under the drink tray with the van off. However with the van running I get 14.2 VDC at both places which I was thinking would happen. Since we only use those outlets for phone or hotspot charging while driving I have no worries about not replacing the Aux battery. This will leave plenty of room for some sort of hardwired and switched air compressor.
Not worried at all about starting with a dead starter battery as I have more than enough coach batteries which can be brought in using the momentary assist button.

John

Make sure your sound system, clock etc kept it's memory and if you have a scanner check make sure there is no keep alive memory code. I doubt it though as many Sprinters have only one battery to keep everything alive. You're probably good to go.