House battery drainage

[Boxster1971]

Originally Posted by lewster

NICE PRINT!!!!

Did you install but not show the iPN-PRO remote from Blue Sky and the ME-RC remote from Magnum? Battery temp sensors for both?

I know showing them would mess up the great wire flow in the diagram………(like the negative from the combiner box to the charge control)….. just checking????

Love the 'ice cube' fuses too. Most folks don't even know they exist….

Yes - I installed all those items and added them to the diagram last night before I hit the sack. Good call on the missing negative from the solar combiner box. I added it this morning. Got the "ice cube" (MRBF) fuse idea from the marine electrical articles I have read. Also noticed that Airstream is now using them on the new battery location under the van.

For your enjoyment I'm attaching the latest diagram. I didn't follow Magnum's recommendation on hooking up the 12V source to the BMK module right on the battery terminals with one of those inline fuses, that I hate. Since the distribution panel was nearby I just powered the BMK module through a spare fuse slot on the panel. I think the very small voltage drop by going that way should not effect the performance. Finding 2A ATC/ATO fuses was a challenge as none of the auto parts stores around me carried them that small. I had to do the on-line order to get them.

When I make mods I keep track of changes in my notebook then when I make a diagram so I can remember what changed. Next I need to make a diagram of the 120V AC side changes with the new inverter.

[coder]

Meh. You've redesigned, replaced or rewired the entire system. I'm still interested in seeing Airstream make the existing components work together the way they can and should. That's what I paid for originally.

Anyway, you've wired the Kenwood just like Airstream did. In the SB-164 thread, you thought the direct connection was wrong. Airstream says they use a power relay at the radio. Are you still sure with ignition off and house power off that the Kenwood draw is 0.1A? No-one else anywhere on the web is complaining about this Kenwood model's power usage, and Airstream publishes 0.001A for the Kenwood.

[Boxster1971]

Originally Posted by coder

Meh. You've redesigned, replaced or rewired the entire system. I'm still interested in seeing Airstream make the existing components work together the way they can and should. That's what I paid for originally.

Anyway, you've wired the Kenwood just like Airstream did. In the SB-164 thread, you thought the direct connection was wrong. Airstream says they use a power relay at the radio. Are you still sure with ignition off and house power off that the Kenwood draw is 0.1A? No-one else anywhere on the web is complaining about this Kenwood model's power usage, and Airstream publishes 0.001A for the Kenwood.

Yes - I left the Kenwood wired the way Airstream installed it. I didn't mean to imply the way Airstream wired it was wrong - it has to be that way if you want to use the radio while camping or parked. Actually the Airstream wiring is very clever with diodes to prevent cross connection between the two battery systems.

My point was it's another factor in the mix of parasitic battery drain. No one on the "web" is going to complain about Kenwood power usage as they have the ignition power wired the way Kenwood recommends, via the vehicle ignition key.

The Kenwood in my Interstate does draw 0.1A when turned OFF with house power disconnect ON, in normal use configuration. I've measured it. It draws a little over 1.0A when on in normal use. The Kenwood does have an internal relay that cuts drain to what I'd guess is 0.001A you quoted, but that relay is only activated if the ignition signal to radio is off. In the Interstate that ignition line is powered by 12V DC fuse #2 and is only off when you turn the house power disconnect to OFF, or pull the #2 fuse. Then to radio is powered up by the Sprinter ignition key.

I redesigned and rebuilt the electrical system to meet my needs rather than paying more for something like an Advanced RV custom built unit. When I got mine in October 2012 the Roadtrek e-Trek was not yet available. At that time it was either a Winnebago ERA, an Advanced RV or an Interstate because I wanted the extended Sprinter. For the money the Interstate was a winner for me. Of course I have not had the problems you are having.

I did my own conversion on my first camper van many years ago. Now I was more interested in getting a good van to travel and then customizing it myself as I determined how I would use it.

[coder]

Got it.

• 1A when the Kenwood unit is on and being used
• 0.1A when unit is off but house power is on
• 0.001A (per Airstream docs) with ignition off and house disconnected

My problem is parking in storage, disconnected, under the cloudy skies of Seattle, so I'm good with the 0.001A Kenwood draw.

In my van, the Atwood propane alarm (70 mA) is OFF when the house power is disconnected. With the Magnum and its remote disconnected, I think everything else adds up to less than 6 Ah per week. The batteries (counting NO solar contribution) should last longer than 2 months at that rate. That's where the Interstate should have been when it rolled off the line in Ohio.

[xrvr]

Listen to Lew, he's right again.

[Boxster1971]

Originally Posted by coder

Got it.

• 1A when the Kenwood unit is on and being used
• 0.1A when unit is off but house power is on
• 0.001A (per Airstream docs) with ignition off and house disconnected

My problem is parking in storage, disconnected, under the cloudy skies of Seattle, so I'm good with the 0.001A Kenwood draw.

In my van, the Atwood propane alarm (70 mA) is OFF when the house power is disconnected. With the Magnum and its remote disconnected, I think everything else adds up to less than 6 Ah per week. The batteries (counting NO solar contribution) should last longer than 2 months at that rate. That's where the Interstate should have been when it rolled off the line in Ohio.

Correct - you have it. I was just thinking your complaints to Airstream about battery drain may have actually caused them to research the problem and issue Service Bulletin 164 to stop the main parasitic drain from the Magnum inverter. Although their solution is not as good as Lew Faber's total disconnect approach.


- - Mike
2013 Lounge EXT on 2012 Sprinter

[Protagonist]

Originally Posted by Boxster1971

Although their solution is not as good as Lew Faber's total disconnect approach.

From Airstream's point of view it's better, because it's the least expensive way to solve the problem, and probably the quickest. As the saying goes, "Good. Fast. Cheap. Pick two."

[Boxster1971]

While working on my van today I did a more accurate measurement of the current required to power the Kenwood. The full up mode with radio on and GPS map displayed was drawing a full 2.0A. So this list should be:

• 2.0A when the Kenwood unit is on and being used
• 0.1A when unit is off but house power is on
• 0.001A (per Airstream docs) with ignition off and house disconnected

That explains why my batteries were down 11AH the other night when I took a group of six from our neighborhood out for dinner and left the Kenwood on for over three hours while we ate dinner. Lesson learned.


- - Mike
2013 Lounge EXT on 2012 Sprinter

[coder]

If I ever get the van fixed enough that I can park it without destroying its batteries, then I have to work on being able to use it for camping off-grid. (We like national parks and forest service parks.)

I don't know yet exactly what SB-164 does. If it disconnects the Magnum Inverter/Charger when the house disconnect switch is selected, then that probably solves a lot of the parking problem.

Using the van off-grid, though, you'd still be unnecessarily losing 10 Ah per day from the Kenwood and Magnum that didn't need to be on. The best solution for both parking the van and using the van off-grid is separate manual disconnect switches for both the Kenwood and the Magnum. You can't just pull a fuse to stop the Kenwood draw, since Airstream shared the Kenwood fuse with other essential stuff.

Even a total battery disconnect doesn't solve the problem of excessive drain while camping off-grid, and I'll bet SB-164 doesn't either. Sigh.

[coder]

It's all a bit sad.

One of the reasons we were originally drawn to the Interstate, and eventually decided to trade in the Airstream trailer for the Interstate, is we wanted more battery capacity for camping off-grid and we wanted a little bit of solar. In the trailer, a little 50W solar panel would have kept the Airstream trailer battery full to the top indefinitely.

We traded that little Airstream trailer that we adored for this Interstate, which has been nothing but trouble.

[Boxster1971]

Originally Posted by coder

If I ever get the van fixed enough that I can park it without destroying its batteries, then I have to work on being able to use it for camping off-grid. (We like national parks and forest service parks.) ....

... Even a total battery disconnect doesn't solve the problem of excessive drain while camping off-grid, and I'll bet SB-164 doesn't either. Sigh.

Yes unfortunately the Interstate is not an optimal design for off-grid camping. I discovered that on our first camping trip. Having to run the LP generator twice a day was a real pain.

I suspect having to power that solenoid in SB-164 to use the coach electrics while camping will make it worse. It will be a lot like the propane solenoid that had to be on to use the cook top or furnace.

When I discovered the limitations of the Interstate for off-grid camping I had two choices. Trade it in for a better off-grid design like an e-Trek or modify my Interstate. I chose the later approach because I have the time and capability.


- - Mike
2013 Interstate Lounge EXT on 2012 Sprinter

[lewster]

Originally Posted by Boxster1971

Yes unfortunately the Interstate is not an optimal design for off-grid camping. I discovered that on our first camping trip. Having to run the LP generator twice a day was a real pain.

I suspect having to power that solenoid in SB-164 to use the coach electrics while camping will make it worse. It will be a lot like the propane solenoid that had to be on to use the cook top or furnace.

When I discovered the limitations of the Interstate for off-grid camping I had two choices. Trade it in for a better off-grid design like an e-Trek or modify my Interstate. I chose the later approach because I have the time and capability.


- - Mike
2013 Interstate Lounge EXT on 2012 Sprinter

Hopefully the solenoid that Airstream included in their 'upgrade' kit is of the latching type: only uses current to open or closed and state in that orientation until it is told to change. If it is similar to the LP solenoid, you probably won't be gaining much.