2015 3500 Battery Drain Problem

[Teja]

I know there have already been many battery drain threads posted, so sorry if this is redundant, would appreciate an accurate answer:

I have a 2015 Sprinter 3500 built out by PleasureWay. It has 2 LI batteries in rear that run all the 'RV' type appliances and add-ons, and the correct size brand-new Interstate battery under the floor board for the engine and all car-related accessories (front cockpit dome lights, headlights & rear lamps, etc.)

Though brand-new and fully tested for both amps and cranking, the engine battery drains to non-starting even after just 5-7 days of being parked.A solar battery-maintainer, clipped to the engine-compartment terminals, helps somewhat, and my NOCO Genius battery-booster turns it over if it's full -dead.

No inner or outer lights are left on when parked, and although I know there can still be a slight 'computer' drain over time, I cannot figure out what could be draining a full new battery to such low/dead levels in under a week or two.

Any clarity on this would be greatly appreciated, thank you.

[JohnnyFry]

This has been an ongoing problem since...forever. My 2008 RT Chevrolet 3500 has the same problem and it is certainly maddening. I have tried measuring the current draw and found that the problem is related to the ECU computer going to sleep. I found that opening and closing the driver door after turning the ignition off seems to accomplish this: so try that first to see if it helps. Bear in mind that the draw is never reduced entirely to zero: the ECU consumes some power even in the sleep state, the radio receiver for the Key Fob is always listening for the unlock signal from your key fob, the dashboard radio has a memory that consumes some small amount of power. That said, the only way to absolutely insure that there is no draw is to disconnect the battery. There are easy to use switches available which attach to the battery and accomplish that task.

[kmgwood51]

I have a 2012 3500 Era. Replaced both house batteries and chassis battery about 18 months ago. Have a 100 w solar cell that keeps all 3 healthy and was very happy it was the first time to have to replace since buying the unit. A few months ago went out to check on her and all 3 were drained dry. Ended up at Mercedes dealer that I have always used and trust. They found that the antenna boot over the cab had leaked and the water dripped down on the Map Light unit and shorted out the board inside. Replaced and all has been fine since. Sounds like it was not the first time they had seen this.

[Hatteras Jim]

Unless you physically disconnect your sprinter vehicle battery, or maintain it on a constant charge or drive it weekly; your battery will go dead. Another fine engineering marvel from Ma Benz. Although, 5 - 7 days is pretty short for a new battery; it takes my 1 year old lead acid 2 weeks to die in the winter. Do a parasitic load test and see what it reads after you reconnect it, about 30 minutes later. Good luck.

[Jon in AZ]

Originally Posted by JohnnyFry

This has been an ongoing problem since...forever. My 2008 RT Chevrolet 3500 has the same problem and it is certainly maddening...

Surprising. My 2014 RT Chevrolet Express 3500 can sit for a month and fires right up, winter or summer. Seems like it could go longer, but I make a habit to exercise it monthly.

[JohnnyFry]

Ma Benz didn’t invent the phenomenon: Chevrolet had it first!

[Road Toad]

Originally Posted by kmgwood51

I have a 2012 3500 Era. "They found that the antenna boot over the cab had leaked and the water dripped down on the Map Light unit and shorted out the board inside. Replaced and all has been fine since.".

My 2013 Sprinter also leaked there.
Discovered it is a widespread Sprinter issue.

[RAA357]

My 2007 RT 210 Versatile can sit for months without starting it and I have no problems starting it or with the house batterys. On a Chevy 3500 Express Chassis.

[RossWilliams]

We have a 2015 3500 Mercedes Sprinter Roadtrek. We have left it out for weeks in sub-zero Minnesota weather with no problem starting it. I may be living on borrowed time...

We just got a promo for a Mercedes dealer for their service for RV sprinters. You might check with a Mercedes local dealer to see if they can find the problem. Or at least tell you there is nothing you can do about it.

[avanti]

All sprinters have significant parasitic loads.
It is very easy to disconnect the battery using disconnect feature located down by the accelerator pedal. No reason not to use it routinely during storage.

Or, if you have solar in the coach, just get a Trik-L-Start and forget about the issue.

[RossWilliams]

Here is an article on trouble-shooting mercedes battery drai problems. http://www.mercedesmedic.com/battery-drain-problem/

[JohnnyFry]

As I remember Booster reported that he does not have the problem with his 2007 Chevrolet RT either. It goes to show that it is not consistant from vehicle to vehicle. There are certainly enough reports that many, but apparently not all, chassis exhibit the problem. I finally gave up and simply live with it.