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. :-).
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