Battery Discharge

bfeeny · June 2022

I have a 2018 CS-C with a 100 AMP RV 27 battery. I've felt that I'm having a lot of phantom discharge so a ran a test this week in my driveway. I unplugged my shore power and made sure my battery switch was on. The sound system was off other than the clock display and the Carbon Monoxide/Propane Detector was showing a green on light. There was no heat on , no lights on or any other visual signs of power usage. When I unplugged last Saturday, the battery read 12.8. Today, Friday, the battery reads 12.1. I welcome any suggestions or comments to help me with this issue which is concerning only when I am boondocking. Yes I do have a 100 watt solar panel and controller

VictoriaP · June 2022

The stereo, TV, USB outlets, fan, Alde, and propane/carbon monoxide detector are all known parasitic draws even when theoretically “off”. The TV & stereo are the worst of those, which is why many of us install kill switches on those.

pthomas745 · June 2022

What are you using to monitor your battery? On my 2017, the sum total of my "parasitic drains" is roughly 5 amp hours a day. (I have a switch for the TV only.) On your 100 amp hour battery, you have approximately 50 amp hours of usable power.

What you don't tell us about your power test: how many days did you run the test? If your parasitic drain is 5 amps a day, in theory, you would have (about) 10 days until your battery reached the 12.1 state of charge. Which would be very close to the "50 percent" state of charge margin most battery wonks consider the low number for maximum battery life.

Next: how are you measuring this 12.1 battery voltage? If the battery switch is on, and the battery isn't "rested", your battery state of charge will always read low. This is true with any battery voltage measuring device. Even the small loads of the parasitic drain will cause the battery voltage measurement to read lower than it actually is. The picture below is an example of the difference in a battery in use compared to a battery "at rest". On the left, the fan is running in my trailer.The battery voltage is saying 12.09, which would seem to say my battery is at the 50 percent state of charge. On the right, the battery switch is off, and it has sat for 10 minutes. The battery voltage is now a bit more "accurate", showing that the battery is about 75 percent state of charge.

It is a good test to run to get to understand your battery and trailer! If you have a multimeter and know how to use it (or the Victron app if you have installed solar) try your battery test again and measure the results with the battery switch off.

Image: https://us.v-cdn.net/5021717/uploads/editor/53/m4erdtn3sqq1.jpg

Marceline · June 2022

How old is the battery?

CharlieRN · June 2022

It may not be a phantom discharge; the parasitic draw of the newer T@B's is pretty high.

On my 2021 320S BD, with battery switch in the "On" position, the draw is over 0.6 amp due to current used by the devices that @VictoriaP lists. Over the course of a day (24 hrs) that's roughly 15 amps, a pretty substantial amount of current considering you're not using the fan, the fridge, lights, etc.

bfeeny · June 2022

The battery is about a year old, My test lasted for 6 days. What if I unplug the TV power from the back? I used the battery monitor in the trailer for my test so my next test using some of these new ideas I will try my multimeter. Thanks for the advice. Any more suggestions?

Sharon_is_SAM · June 2022

You may want to consider changing out the USB outlets for 12V outlets. Use a 12V to USB adapter when you charge devices. We eliminated the USB outlets in our TaB.

Here is a really good thread to read: https://tab-rv.vanillacommunity.com/discussion/6415/phantom-drain/p1

SLJ · June 2022

Not many parasitic draws here. Added a switch panel (upper left). First switch is the overhead LEDs (which have now been replaced with LEDs that don't draw when off), second switch is the USB outlets, third switch is the Jensen stereo, fourth is the blu-ray player, fifth switch is the TV and antenna amplifier. Solar converter, and the carbon monoxide detector stay on for safety.

Image: https://us.v-cdn.net/5021717/uploads/editor/ba/corsn9kf2877.jpg

CharlieRN · June 2022

That looks like a terrific idea and great install @SLJ.

Any chance you can post some details about installation and the BOM, maybe even some photos?

SLJ · June 2022

CharlieRN said:

That looks like a terrific idea and great install @SLJ.
Any chance you can post some details about installation and the BOM, maybe even some photos?

Here's more info. Did take some time to track down all the correct wires. LED feeds are behind the microwave and most others I grabbed under the drivers side bench. https://solocanoes.com/camper.htm

CharlieRN · June 2022

Informative web page! Thanks @SLJ.

GigHarborTom · June 2022

This is not exactly user friendly. Why the devil are we so electronically dependent when boondocking is suppose to be the mission ? I am impressed with the expertise of most of the members of this forum. The unreliability of the systems takes the fun out of camping. Can be very expensve to m

Sharon_is_SAM · June 2022

@GigHarborTom - actually, boondocking is not the mission for the majority of purchasers of nuCamp products. NuCamp follows consumer demands which dictates their sales down the road. Most owners typically use hookups, hence the microwave option and choice to have a 2 way vs a 3 way frig (3 way option now retired). Consumers often want more glamping features including Bluetooth entertainment systems, TVs, user friendly tank and battery monitors, etc. All of these items do add complexity to the build and requires commitment from the owner to understand what they own. The learning curve can be steep for any new owner.

GigHarborTom · June 2022

Well advised, we do like the amenities. We just do not use the entertainment systems. Also this old goat is used to hookups and boondocking only a couple times a year. A couple major restorations of 50 plus year old trailers and just not up to speed on the digital age. The learning curve of modern systems steep for this 82 year old goat.
I do appreciate the support from you and all here.

Denny16 · June 2022

Tom I hear where you are coming from. My first RV was a 1959ish Kenskill 27’ (or 29-foot.) trailer that only had a 12VDC light in the Dinette (along with a gas light), everything else was 120 VAC, including the hot water heater. The stove was a residential style gas wall heater, I took out and replaced with a boat cast iron Fosc’le stove, a more learned mate helped my install using the gas burner from the wall heater.

That was it, everything else was a normal (somewhat smaller version) of apartment appliances, stove, frig, toilet, etc. Water to the washroom and galley sink were City hookups, as was 30-amp 120VAC power.

I did have a small 10-gallon water tank, I used to fill with bottled water (from 5-gallon jugs) which had a galley boat hand pump. Nothing special to learn, except how to block it up on concrete piers. Nothing high tech.
Cheers

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