That’s my question to Airstream. I’ve also started testing a Smart Lithium battery from Renogy with an RJ45 Network port which accepts a little push button that puts the battery bank into storage/hibernation mode. It draws less than 100 microamps of current while in hibernation. That’s 0.0001 amps or 0.1 mA of BMS current. A 3-second push on the button turns all the batteries back on again. https://www.renogy.com/12v-100ah-smart-lithium-iron-phosphate-battery-w-self-heating-function/
Here’s another piece of the puzzle from one of my long-time readers. If true this would explain a lot…
The Airstream USE/STORE SW is a Magnetic Latch Sw that disconnects the Converter from the Battery. Des not disconnect the Battery from load Bus. Propane Detector and Radio will be parasitic draw. The Magnetic Latch Sw is powered from the Battery. If Battery voltage is too low the Magnetic Sw cannot reconnect the Converter to Charge the Battery. Charge Batteries externally or use Auto Jumper cables just long enough to reposition the Magnetic Relay.
I suspect something like this on the negative battery terminal would work. But since it also disconnects power from the breakaway trailer brakes you can’t disconnect the neg terminal while towing.
This is a lesson a lot of us Airstream users have learned the hard way. I missed this tidbit of information in the owners manual. The carbon monoxide detector is hard wired to the batteries so even with the battery disconnect switch on there is a small current drain. I ruined a pair of lead acid batteries by overdrawing them. After that I kept a trickle charger on the batteries while in storage. I went to several of your seminars in Rock Springs and learned a lot. I converted my Airstream to lithium batteries this past fall and now just disconnect the negative lead on the battery when I store it for a few weeks.
Yes many LP/CO typical detectors are using around 100 to 120 ma of current. But the one from Jayco on my 2020 is a RvSafe and is stamped with a usage of 17ma. Make a big difference.
If the LP/CO detector isn’t being turned off by the battery disconnect switch, that would explain the battery discharge. A 17 mA drain would take 588 days to completely discharge 240Ah of Lithium batteries. So that’s less than 50Ah of battery discharge over 4 months of storage. Not fantastic, but certainly acceptable.
Why are some RV LP/CO detectors direct-wired to the batteries, and other manufacturers wire the detectors through the battery disconnect switch?
Is there an industry standard or applicable code or regulation on how RV LP/CO detectors are wired?
As best as I can determine, the only “parasitic draw” items on my motorhome (checked with a multimeter) include:
a. Use/Store solenoid (latching relay) (almost unmeasurable, <1mA)
b. Solar controller (minimal, and only at night or when panels are covered)
c. Victron Smart shunt (minimal (<1mA), for data collection, memory storage, & Bluetooth communication).
Though I have not checked, what is the energy consumption rate of the internal BMS of LiFePO4 batteries? I presume less than 1mA (ignoring internal battery heater consumption).
He also said he turned the fridge on to propane. The control system uses 12v DC to run so he can’t turn off the battery disconnect switch. As others said the combined LP/CO detector is hard wired to the battery.
I inspected a new Holiday Rambler Nautica 33TL diesel pusher yesterday. I specifically checked and when the coach/house "salesman" switch was OFF. the hard wired CO detector was still powered by 12v DC!!
Usually turning the disconnect to OFF turns off all power by disconnecting the batteries. However, I’ve seen a few battery disconnect switches labeled the other way. So Disconnect OFF was power ON, and Disconnect ON was power OFF. 😁
I see this same issue with many trailers that we work on. Often the parasitic draw comes from the LP/CO detector and Solar controller that are hard wired to the batteries, bypassing the battery switch. A solar controller requires battery voltage to operate, and in low light conditions it will eventually drain t the batteries. First thing I would is to use a DC clampmeter on the battery cables to determine what the draw is and the start pulling fuses and disconnecting items until it is discovered. I have also noted that the converter charger lower section often has a led light that stays on when the power is supposed to be off.
Parasitic loads include propane & fire alarms, as well as the solar controller (on my lithium equipped van) which has a 12v positive lead attached to the BATTERY side of the cut-off battery switch… without which the controller won’t transfer amperage from the solar panel…
It depends on how big your inverter is. A 2,000-watt in inverter can easily draw 200 amps of current, and a 3,000-watt inverter can be up to 300 amps. A lot of the basic battery disconnects are only rated for 100 amperes continuous duty.
That's odd because I've got two Expion 360's in my Arctic Fox. The trailer is stored outside next to our house. It hasn't moved in over six months. I have installed knife switches on the batteries to insure there is no discharging (or charging) and the supposedly 'whole trailer' battery cutoff switch is off. Also, the 700 watts of solar on the roof is cut off with another switch preventing any charge current from reaching the batteries. The batteries were at 70% (13.4, I think) six months ago. I just checked them last week and they are still at 70% and 13.4. I hope these folks (and you) find a solution to this dilemma.
That’s my question to Airstream. I’ve also started testing a Smart Lithium battery from Renogy with an RJ45 Network port which accepts a little push button that puts the battery bank into storage/hibernation mode. It draws less than 100 microamps of current while in hibernation. That’s 0.0001 amps or 0.1 mA of BMS current. A 3-second push on the button turns all the batteries back on again. https://www.renogy.com/12v-100ah-smart-lithium-iron-phosphate-battery-w-self-heating-function/
Here’s another piece of the puzzle from one of my long-time readers. If true this would explain a lot…
The Airstream USE/STORE SW is a Magnetic Latch Sw that disconnects the Converter from the Battery. Des not disconnect the Battery from load Bus. Propane Detector and Radio will be parasitic draw. The Magnetic Latch Sw is powered from the Battery. If Battery voltage is too low the Magnetic Sw cannot reconnect the Converter to Charge the Battery. Charge Batteries externally or use Auto Jumper cables just long enough to reposition the Magnetic Relay.
I suspect something like this on the negative battery terminal would work. But since it also disconnects power from the breakaway trailer brakes you can’t disconnect the neg terminal while towing.
https://a.co/d/bxjN3bE
This is a lesson a lot of us Airstream users have learned the hard way. I missed this tidbit of information in the owners manual. The carbon monoxide detector is hard wired to the batteries so even with the battery disconnect switch on there is a small current drain. I ruined a pair of lead acid batteries by overdrawing them. After that I kept a trickle charger on the batteries while in storage. I went to several of your seminars in Rock Springs and learned a lot. I converted my Airstream to lithium batteries this past fall and now just disconnect the negative lead on the battery when I store it for a few weeks.
Yes many LP/CO typical detectors are using around 100 to 120 ma of current. But the one from Jayco on my 2020 is a RvSafe and is stamped with a usage of 17ma. Make a big difference.
If the LP/CO detector isn’t being turned off by the battery disconnect switch, that would explain the battery discharge. A 17 mA drain would take 588 days to completely discharge 240Ah of Lithium batteries. So that’s less than 50Ah of battery discharge over 4 months of storage. Not fantastic, but certainly acceptable.
Why are some RV LP/CO detectors direct-wired to the batteries, and other manufacturers wire the detectors through the battery disconnect switch?
Is there an industry standard or applicable code or regulation on how RV LP/CO detectors are wired?
As best as I can determine, the only “parasitic draw” items on my motorhome (checked with a multimeter) include:
a. Use/Store solenoid (latching relay) (almost unmeasurable, <1mA)
b. Solar controller (minimal, and only at night or when panels are covered)
c. Victron Smart shunt (minimal (<1mA), for data collection, memory storage, & Bluetooth communication).
Though I have not checked, what is the energy consumption rate of the internal BMS of LiFePO4 batteries? I presume less than 1mA (ignoring internal battery heater consumption).
He also said he turned the fridge on to propane. The control system uses 12v DC to run so he can’t turn off the battery disconnect switch. As others said the combined LP/CO detector is hard wired to the battery.
I inspected a new Holiday Rambler Nautica 33TL diesel pusher yesterday. I specifically checked and when the coach/house "salesman" switch was OFF. the hard wired CO detector was still powered by 12v DC!!
Does turning the battery disconnect OFF, mean the batteries are connected since the disconnect is off?
Usually turning the disconnect to OFF turns off all power by disconnecting the batteries. However, I’ve seen a few battery disconnect switches labeled the other way. So Disconnect OFF was power ON, and Disconnect ON was power OFF. 😁
I see this same issue with many trailers that we work on. Often the parasitic draw comes from the LP/CO detector and Solar controller that are hard wired to the batteries, bypassing the battery switch. A solar controller requires battery voltage to operate, and in low light conditions it will eventually drain t the batteries. First thing I would is to use a DC clampmeter on the battery cables to determine what the draw is and the start pulling fuses and disconnecting items until it is discovered. I have also noted that the converter charger lower section often has a led light that stays on when the power is supposed to be off.
Parasitic loads include propane & fire alarms, as well as the solar controller (on my lithium equipped van) which has a 12v positive lead attached to the BATTERY side of the cut-off battery switch… without which the controller won’t transfer amperage from the solar panel…
It’s my understanding that the Fantastic Fan is also a parasitic draw unless the on/off switch is off and the fan speed dial is set to zero.
It would be interesting to test exactly what is drawing current with the battery switch off.
Mike, What brand of battery disconnect do you recommend? I don't have a lot of room left in the battery box. Airstream 2023 25' Globetrotter FBT.
It depends on how big your inverter is. A 2,000-watt in inverter can easily draw 200 amps of current, and a 3,000-watt inverter can be up to 300 amps. A lot of the basic battery disconnects are only rated for 100 amperes continuous duty.
That's odd because I've got two Expion 360's in my Arctic Fox. The trailer is stored outside next to our house. It hasn't moved in over six months. I have installed knife switches on the batteries to insure there is no discharging (or charging) and the supposedly 'whole trailer' battery cutoff switch is off. Also, the 700 watts of solar on the roof is cut off with another switch preventing any charge current from reaching the batteries. The batteries were at 70% (13.4, I think) six months ago. I just checked them last week and they are still at 70% and 13.4. I hope these folks (and you) find a solution to this dilemma.