Adding DC Outlets - February 2026, three outlets ~ $50 total.

 Monday, February 9th, we awoke to minus 20F temps....not conducive to enjoying the outdoors, so I decided to lite a fire in the barn and work on the Serenity Falcon. 

9Feb2026 04:15AM

It has been one of the coldest winters in years, we have mostly enjoyed the weather and snow...but this is a bit much. 

Since we upgraded the batteries in the Serenity, we find that we don't plug in much and most of the time are operating on 12V DC power. We have also started bringing with us a 12V compressor refrigerator (cooler) and installed a Starlink Mini in our skylight that can operate from a 12V source. However, the Serenity has only two 12V outlets, in less than convenient locations. To remedy this I installed three, multi-port 12V/USB outlets. 

1) Outside compartment near the RV entry.  This is to power our 12V cooler when we move it outside and what ever else USB device we need to power. It has 3 12V outlets. 1 C port, and 3 USB ports. It is also switchable and has a voltmeter. Everything is switched such that when off it does not use any power. 

Eugizmo, 12V, 200W outlet. 

Under the seat behind the passenger

I powered this and the second outlet from the same power source as my leveler jacks, which is protected by a breaker and the socket is also fused.

2) Behind the passenger seat. I used the same power source but installed it in the seat support behind the passenger seat.  This unit also has a meter and when switched off draws no power. 

Behind the Passenger seat

It is always a bit intimidating to drill holes in fine cabinetry. 

12V socket and 2 USB ports

This is a simpler unit of a single 12V socket and two USB ports. It has a 20A rating (240W).

3) In the corner under the rear bed. I put this one here specifically because this is where the 12V cooler lives when it is inside the RV.  The electric bed goes over the cooler at night but it is accessible during the day. I used the same outlet I put behind the passenger seat but for some reason the meter doesn't work, but I really don't care as long as I can switch if off. 

Under the electric bed

I pulled power from a previous USB install I did years ago to power our phones at night. The socket I stole from is in the rear storage compartment under the bed. Honestly, I don't recall where it got power, but I know it is fused, because I did it.  

These installs will allow us to run devices that are 12V without running our inverters, thus allowing our batteries to last a bit longer. 

We have a large 3000W inverter that runs the house 120V system and a small more efficient 400W inverter in the media cabinet, that I installed when we bought the Serenity, that power the TV and a few USB devices (Like the Firestick, Roku and Chrome dongle). 

We are working towards a early March departure south this year, so I am happy to get these off my list before we launch. 

Factory Radio Replacement - February 2025 ($1338)

 The Serenity came with the Sprinter factory radio.  It is a Becker A15, model RY2550, manufactured by Alpine. I guess in 2015 it was OK, but we have hated it from day one. 

We hated it so much, we basically only used it to stream audio from my phone or a tablet. The Nav on it was so bad we used my phone or an Android tablet with google maps for directions that sat on the cup holder below the radio. It would some times slide off on a turn. 

With the approval of my CFO (June), I finally ordered a replacement from Crutchfield.

I chose the Kenwood Excelon Reference DMX1057XR, here is a link to the Crutchfield site. 

Crutchfield DMX1057XR

With all the adaptors needed to install it, it was not cheap. 

Removal of the Becker was pretty easy. The bezel is just held on with 6 clips, 4 screws and the radio comes out. 

For about $25 Crutchfield will prewire a harness that connects to your manufactures plug, it makes the job much easier. Their directions are pretty good with the exception of a few omissions. 

Just incase anyone reads this that is doing the same job. 

- Neither 3.5mm audio plug is needed, tape them up and tuck them away.

- The blue 4 pin plug goes to the old Becker GPS box in the glove box, it is no longer needed.

- The black coax plug is for the Radio Antenna - use the coax to Antenna adaptor.

- The green coax is the Backup Cam - use the coax to RCA adaptor to AV In on the Kenwood.

- The purple 4 pin goes to the USB A port in front of the driver - use the 4pin to USB adaptor.

The back of the dash cavern is quite large, in fact I dropped a roll of black tape in there and could not retrieve it, hopefully it will not cause issues in the future. I tucked all the wires and adaptors into the cavern and installed the Kenwood per the instructions. I am not impressed with the way they hold the radio, plastic clips on the side, time will tell if it holds up. 

The job took about 3 or 4 hours, but much of it was figuring out the wiring, it could be done in a few hours if you have done it before. 

I tested it most of the functions and things appear to work as they should. It sure is a better screen. 

I put the GPS receiver and the microphone in the tray above the radio, I drilled a hole for the wires that is covered by the rubber mat in that tray. You can see the microphone just sticking up above the radio head in this picture. 

One remaining item that I am contemplating is removing the GPS unit from the glove box since it is taking up unnecessary space.  I will make an update to this blog if I remove it. 

We are leaving in a few weeks for Florida, I am sure it will be much better than the old Becker. 

Update: Today, 02Feb25, I removed the annoying GPS unit that was in the glove box. 

It took up a lot of space in the glove box.

 

Three screws for the glove box, one for the side panel and three more for the under dash liner, three more for the mount, three more for the unit itself and it was off. 

There were 3 connections to the box, I did not know what they all did, so after removal, I reconnected them and stuffed it in the back of the dash.

I used metal tape to close the hole in the back of the dash.  It is much more roomy now. 

It was a fun, quick and pretty easy upgrade.  

Low Power Propane Switch - March 2024 ($55)

After doing some internet searching, I found that Leonard Casella in Pennsylvania sells a modified low power switch.  I contacted him and he sent me one for $55. The install was fairly easy, it uses the same wires but needs to have a ground wire which I tapped off the compartment light. 

The switch consists of a three way toggle with a BUCK converter that lowers the current draw to keep the solenoid open. The LED is for testing purposes, I did not use it. 

This is the original Propane switch

This is the new one installed. There is not a good place for the BUCK converter in the Serenity, so I stuck it to the utility compartment wall. I tapped the ground off the compartment light. 

I turned on the propane stove to ensure the valve was open in the On and PS positions. 

It reduces the power draw by 0.83A and only consumes 0.15A while keeping the gas solenoid open. 

This is the battery monitor with the switch in the On position.

This is the monitor with the switch in the PS position. 

This is the monitor in the off position.

I consider this a success and still can't understand why an RV manufacturer would put such a device in a rig with limited battery capacity. 

Air Conditioner Soft Start - February 2024 ($263)

Upgrading the electrical on the Serenity provides enough battery power to run the AC off the batteries if needed. Frankly, I don't plan on doing this a lot but having the option is always nice. AC units draw lots of current on startup which can cause issues with the inverter. There are several companies that offer a solution to dampen the current draw. 

 

I chose SoftStartRV because it was just a bit less expensive and had good reviews. 

https://www.softstartrv.com/

This graph (from the SoftStartRV website) shows how the soft start damps the current draw during AC start.

This graph is from a Dometic 15K Penguin II AC unit, which is the unit we have on our Serenity. 

The install is pretty easy, but does require some rewiring of the AC unit. You basically remove the AC cover, install the unit and rewire using the crimp connectors provided. It took about an hour.

The AC unit without the cover. 

I tucked the softstart in next to the electric motor and secured it with zip ties. It fit pretty easily. It has three LEDs that show status, which are good to verify operation before putting the cover back on the AC unit. 

I ran it for over 30 mins in heat pump mode, since it is winter. It definitely has less of a surge on start. It seems to work as advertised, I will not attempt operating the AC off the batteries until I have my Epoch batteries which are due the end of March. We plan to leave before the end of March and return in the fist week of May, so it will be sometime before I can do the final testing. 

Electrical Upgrade - More Testing, Chasing Phantom Loads. February 2024

Batteries - Epoch has pushed out the delivery of my batteries to the end of March. I spoke with the company yesterday, they tried to get me to take a 460A single battery that they have in stock. I looked at the dimensions of this battery, but this will not work for me. 

We plan to leave on a trip before the end of March, so I am going to tidy up the install of Matt's TimeUSB batteries to make them suitable for an extended field test. These batteries have a 280Ah capacity versus the Epoch 600Ah capacity, but they are still over 2X the original 105Ah the Serenity came with stock. 

In the meantime, I have put the Serenity back together. June feels better about it now and has started stocking it for our spring trip. 

Phantom Current Draw - Short of disconnecting the batteries entirely, all RV systems have some current draw even when everything is turned off. For example, in the Serenity here are a few I am aware of; Antenna booster, step motor/light, Jensen Radio, Power Vent, leveler jacks, and C02 detector. 

I was aware of these potential loads, but before I put in the battery monitor, they were difficult to quantify. 

Using the battery monitor, I found that there was what I considered too much phantom current draw when the system was in standby mode. I define standby mode as everything OFF but the house disconnect switch ON.  The house disconnect switch powers the DC circuit panel. We almost never turn off the house disconnect switch. It needs to be on to run the refrigerator, furnace, etc., but the rig should use minimal power until something is actually turned on. 

Here is what the Victron battery monitor sees with the house disconnect ON but everything in the RV OFF. 

The house batteries are suppling 1.16A of power to something. That is a lot of power to do nothing. 

Here is what the Victron battery monitor sees with the house disconnect OFF but everything in the RV OFF. 

The house batteries are now suppling 0.13A of power. This is a pretty small number. 

I monitored the draw while pulling each of the 8 fuses in the DC panel and found that the bulk of the phantom power came from Circuit #1. The EEE documentation shows the following on that circuit.

The documentation from EEE is very good and I was able to find each of these circuits and I eliminated all of them from. 

I was scratching my head, so I contacted EEE. 

Willie Neufield at EEE suggested I look at the propane switch and he was right. Why the excellent documentation from EE failed to list the propane valve is a mystery to me. 

Here is what the Victron battery monitor sees with the house disconnect ON but everything in the RV OFF, including the outside Propane switch OFF.

It is now only drawing 0.39A, so that switch is using about 0.8A just to keep the propane valve open. If you are boondocking, you need propane for the refrigerator and the furnace.  

The Serenity came with batteries that have a 105Ah capacity.  This setup consumes 19-20 Ah of your battery capacity every day, close to 20% of your battery is used just keep a valve open. I understand that for safety the valve needs to fail closed, but this some really poor engineering in my opinion. 

It is also one more reason why I am still considering going to a compressor refrigerator, at least you don't need propane to keep it running when boondocking. 

Of course there are smart people out there and there are alternatives. In the future, I will be making some kind of a modification to mitigate this issue. The one I am considering will reduce the load for the valve down to about 0.15A. This is much more reasonable. 

Assuming I modify the switch to get it to 0.15A, my total phantom load, with everything in the RV OFF but the house disconnect ON, would be about 0.5A. This is 12Ah per day. My Epoch batteries will have 600Ah of capacity, so with minimal solar assist you could park for at least 2 months before the batteries would run down. That should be enough. :-). 

Electrical Upgrade - Testing, January 2024, Final install May 2024, Final Cost

 As of the end of January, I have all the components installed but my batteries are taking a long boat ride from China.  I have a pair of TimeUSB Lithium batteries that technically belong to my son. They are two 140Ah batteries for a total capacity of 280Ah.  I decided to put these in the LTV for debug purposes. 

They easily fit in the planned location since the are a bit smaller than the Epoch batteries.

I was able to use the 2/0 wires that I removed to make the connections. When the final batteries go in they will be connected with 4/0 wire. 

I did not just turn everything on, I tried to do it sequentially to verify each component was working as it should before turning on the next.  And I did swap the monitor cables for the Solar Controller and the Battery Monitor (even though they were clearly labeled...DOH!), but it just blew the 1A line fuse on the Battery Monitor. I had to wait 2 days for a new fuse but luckily no harm was done.  

Xantrex Inverter - I tested this both in bypass and inverter mode. It seems to work as it should, I ran it up to loads of 1500Watts while testing.

Grid pass through mode. 

Inverting while powering the heat gun on low. 

Victron BMV-712 Battery Monitor -  The Victron battery monitor is capable of monitoring two batteries, but the second input is voltage only. The primary monitor is the house batteries and I connected the second to the chassis battery. I had to remove my chassis battery charger, so monitoring the chassis battery is helpful. 

The 3A draw is a few lights and whatever else is on. If I turn off all the lights, it draws about 1.5Amps or 20 Watts. 

There are a few things in the coach that are powered all the time.  Those that I can think of are the Radio, the door step under light (if the door is open), the CO2 detector and the Inverter in standby mode.

Victron Solar Controller - I verified that the solar controller connects to the App via Bluetooth, but until I take it out of the barn, I will not be able to test the solar. 

The solar controller is off because there is not enough solar to turn on the charger, but at least it reports the correct house battery voltage. 

Kisae DC-DC Charger - I did not buy the monitor for the Kisae charger, but did verify it was putting in current the batteries with the engine running. 

When charging, the Kisae continuously scrolls between charge voltage and charge current. 

This pictures shows it is charging at 14Volts.

And it is putting in 40+ Amps to the house batteries. 

I verified that the BMV-712 is actually reporting a charge going into the house batteries. 

The Kisae reports 40A and the BMV-712 only sees 33A going into the battery.  I am guessing this is because the Kisae itself takes power and the lights etc. in the coach take power that is not put into the batteries. I will have to see if I can find out what the Kisae draws by itself. 

As best I can tell, everything is working as I hoped it would.  When I get the Epoch batteries installed I will update all the parameters and do some real testing. 

I also have to put the RV back together, I have removed several of outside compartment doors, emptied every interior compartment, removed all the drawers, removed the table and a few other things. It will take a day just to put things back to where they go. 

So now I wait for my Epoch Batteries. 

May 2024 - My Epoch batteries arrived  21March, about two days after we left on or road trip,  We returned from our trip on 3May so they have been sitting in garage waiting for install. 

12May, I removed Matt's TimeUSB batteries and installed the Epoch batteries. They are only slightly larger but have over 2X the capacity, 300Ah each vs 140Ah each, have self heaters so they can be charged at low temperatures and have built in blue tooth monitoring. Of course they are over twice the price but pack a lot of function in a very small foot print. 

To make them fit, I also had to shave the plastic handles off one of the batteries, I planned this and did verify with the battery manufacturer that this would not be a problem. 

The batteries have a different terminal configuration which required a change in the battery wiring and due to the larger current capacity, I had to go from 2/0 to 4/0 wire, which is no fun to work with. 

The final install fits quite well. 

One of the added features is a built in battery monitor. It is nice to be able to check each battery separately with charge info and temperature. I took this picture while running the heat pump off the batteries. 

The following is simply a record for me.

Final Schematic: 2016SerenityLithium.pdf

Final Material List and Cost. LTVLithium.xls

That is the end of this project, I found it fun and rewarding.  

Electrical Upgrade - Control Panels, Trim and Inverter Connections. January 2024

Control Panels - I mounted all the control panels in the same location EEE used, over the wardrobe closet. 

Brother Tom came over and helped me make the escutcheon trim, he is better at it than me.  We used 1/8" thick ABS plastic to make the escutcheons. 

Any mistakes (and there were a few) were made by me, but they are hardly noticeable. 

Covering up - I put the solar controller and the solar disconnect switch in the back of the wardrobe closet. It was convenient because that is where EEE had put the solar controller originally.

 

It is a hidden space so I was not too concerned about looks, but I may add some type of trim around the components later. 

Inverter Wiring - I first connected the new 10AWG AC wiring to the inverter, the AC IN feed from the panel (Shore/Gen) and the Inverter AC Out back to the panel. The lock down connectors on the Xantrex make this pretty easy. The previous inverter (Magnum) controlled the inverter by using a 12V power wire from the panel. This gets turned off when the disconnect in the stair well is turned off. This allows turning off the inverter by connecting this wire to the ACC input on the Xantrex inverter.  The inverter did not come with a connector for this, but I made one from a Mercedes pin connector. I also connected the remote panel via the RJ12 connector. 

After making the AC connections and control connections, I made up the 4/0 cables to connect the Lynx Power bus to the Inverter.  I torqued them to spec and rechecked everything twice. 

My batteries were due on the 20Jan but have been delayed due to the attacks by Yemen's Iran-aligned Houthi militants on ships in the Red Sea. Ships are being diverted around the tip of Africa causing 3-4 weeks of delays.  My new ship date is 14Feb2024.

Since everything is in place sans the batteries, I may just put a set of batteries in to test and debug.  The tricky part is that the location of the battery connections is different on my new batteries. I only have enough 4/0 cable to do the job, if I can makeup some cables from what I pulled out, I will give it a try, otherwise I will have to wait for my batteries.