Gen 1 Vampire Drain (Possibly) Solved (or Hacked)

[Yossarian]

Hmmm. How about a 12v charging system consisting of PV panels, controller and storage battery that connects through the 7 pin tow harness receptacle?

I'd envision a few flexible PV panels that could be spread out on the roof and anchored at the cross-bar accessory ports. The controller and storage battery could go in the frunk and connect to the panels through a flat wire harness; this would allow frunk to close easily and not damage the wire. Another flat harness could be used to connect to the the tow harness receptacle at the rear. The idea behind ading a small storage battery is to help charging continue through the non-daylight hours.

No EE background so not sure how viable any of this is. It wouldn't be needed at all if it's possible to safely (i. e., not brick the vehicle) disconnect the 12v system via a simple switch.

Sponsored

 

[WhidbeyIsland]

So.. just to clarify, is the issue that when the R1 is plugged into a L2 charger for an extended time, say, several weeks, the 12v is not getting maintained and discharges over time?

 

[racekarl]

So.. just to clarify, is the issue that when the R1 is plugged into a L2 charger for an extended time, say, several weeks, the 12v is not getting maintained and discharges over time?

I don't think so. As I understand it the claim is that the HV battery is used to maintain the 12V battery, so if you leave the vehicle unattended the HV battery slowly drains as it maintains the 12V battery.

OP's idea is to offset that by directly maintaining the 12V battery/ies(?) from wall power, so the HV battery never needs to give any charge to the 12V.

The theory as to why this might be desirable is summarized by @Zoidz:

Several control modules and the HV->12V inverter have to power up to charge the 12 battery when sitting idle. That takes as much, and very likely more power than the actual charging of the 12v battery. By trickle charging from another source, you eliminate that Vampire Drain since the control modules and inverter don't power up...

No one has tested the power drawn by a battery maintainer vs. that drawn by the EVSE while maintaining the HV battery charge, so no one knows for sure if that theory is true.

 

[HyperionMark]

Heading out camping this weekend. Our camper has a Victron solar/battery system where I can see draw from the system via bluetooh. I can check at multiple points to see if I'm getting a high draw (camper charging truck) when very little is on inside the camper.

 

[Singletracker]

There have been reports of bricking the vehicle if you physically disconnect the 12 volt battery. With early dual battery vehicles, Rivian techs told people about a specific procedure they had to follow when changing batteries to avoid bricking. There are threads here about owners who changed their battery and had issues. I suspect that the number of bricking incidents will increase if people install 12v cutoff switches. IMO not worth if 1%-2% drain really bothers you and if 12v trickle might be the solution.

Thanks for the info. Actually, what would bother me more than the drain, when I’m at home, would be always hooking up to a trickle charger. I can see how this would be a good strategy when leaving the vehicle for long periods, however. It doesn’t help with the long term remote camping issue. Oh, well.

 

[Singletracker]

I already have an EcoFlo portable power station and a portable solar panel. I use this to run my refrigerator when I’m camping, thus avoiding drain on the vehicle. Could I not just connect a trickle charger to the EcoFlo, thus maintaining the Rivian 12v system and minimizing VD. I can easily recharge the EcoFlo with the solar panels or be recharging the EcoFlo with the panels, while the EcoFlo is simultaneously powering whatever.

My EcoFlo stats:

•Sizeable 768Wh capacity and 800W output
•Provide up to 1.8kWh a day with solar charging
•Fastest Recharge 0-100% in only 70 min
•Safest LFP battery provides 10 years of use
•First power station with a TÜV Rheinland safety certification
•X-Boost output to 1600W and run 80% of home appliances
•4 ways to charge: AC, car, solar, and USB-C

 

[Dark-Fx]

Yeah! This is what I’m talking about. If it’s possible to just disconnect the 12v with a switch, it may solve the problem. No 12v, no drain. I would certainly put the switch externally, where it could be accessed without opening the vehicle. Wouldn’t want to trust the frunk to not close, then being SOL. Although, I believe there is external access to a closed frunk. As a bonus, add a solar panel to trickle charge the 12v, if needed. Additionally, I wonder it this would create any system issues upon reconnecting.

Not sure if Rivian has set the vehicle up this way, but some vehicles require recalibrating hardware after an extended battery voltage loss situation.

 

[jplblue]

I already have an EcoFlo portable power station and a portable solar panel. I use this to run my refrigerator when I’m camping, thus avoiding drain on the vehicle. Could I not just connect a trickle charger to the EcoFlo, thus maintaining the Rivian 12v system and minimizing VD. I can easily recharge the EcoFlo with the solar panels or be recharging the EcoFlo with the panels, while the EcoFlo is simultaneously powering whatever.

My EcoFlo stats:

•Sizeable 768Wh capacity and 800W output
•Provide up to 1.8kWh a day with solar charging
•Fastest Recharge 0-100% in only 70 min
•Safest LFP battery provides 10 years of use
•First power station with a TÜV Rheinland safety certification
•X-Boost output to 1600W and run 80% of home appliances
•4 ways to charge: AC, car, solar, and USB-C

You should try and let us know the results (and how to do it) .

 

[CarlM408]

This all seems pretty easy to try out, at home feeding through a power meter for testing to see if this is really a positive worth the effort or not, or when camping feeding from our big camp battery (which itself could be solar charged instead of from the vehicle, or just use a solar battery tender).

For testing, one of these seems like it would totally do the trick (12v power at the trailer hitch is always hot??). https://www.amazon.com/POLLAK-11-896-7-Way-Outlet-Adapter/dp/B002UC8U7G
And then a cigaret lighter style battery tender and a power meter to see what it draws vs. what is saved...

 

[HyperionMark]

This all seems pretty easy to try out, at home feeding through a power meter for testing to see if this is really a positive worth the effort or not, or when camping feeding from our big camp battery (which itself could be solar charged instead of from the vehicle, or just use a solar battery tender).

For testing, one of these seems like it would totally do the trick (12v power at the trailer hitch is always hot??). https://www.amazon.com/POLLAK-11-896-7-Way-Outlet-Adapter/dp/B002UC8U7G
And then a cigaret lighter style battery tender and a power meter to see what it draws vs. what is saved...

Love this idea!
I don't think 12v at the hitch is hot if you turn the setting to low energy use while in camp mode. We were plugged in all night with that setting and the truck did not keep our camper battery topped up like it normally would.

 

[FooF]

Love this idea!
I don't think 12v at the hitch is hot if you turn the setting to low energy use while in camp mode. We were plugged in all night with that setting and the truck did not keep our camper battery topped up like it normally would.

this would be better since it should hook directly to a trickle charger.
https://www.amazon.com/VIAIR-7-Way-...51c-43bd-a2a2-b8ddbe8a740b&pd_rd_i=B0CMDJRBDB

 

[nomis]

Anyone know how effective "vehicle shipping mode" is in maintaining SOC? Probably not as effective as trickle charger but curious to know the difference.

 

[NY_Rob]

Anyone know how effective "vehicle shipping mode" is in maintaining SOC? Probably not as effective as trickle charger but curious to know the difference.

Many software updates ago, Shipping Mode actually did materially lower vampire drain, then they changed something to the point that Shipping Mode doesn't do much of anything any longer as far as vampire drain is concerned. Same with Service Mode... not very useful any longer in reducing vampire drain.

 

[HyperionMark]

Agreed, those modes don't do much. At this point the camp mode with all energy off is probably better. But still no cure.

 

[HaveBlue]

Okay. Let me think about that ? There sure seems to be a lot of concern about charging at home overnight. Maybe I’m missing something ? Isn’t that pretty insignificant? I’m sure some have much higher electricity rates than I do, so I understand that could be a concern. I pay about $.07/kWh at home. So, if I have to add an additional 2/kWh per day to account for the VD, it’s only $0.14/day. Ouch! Again, for me, this becomes more of an issue when I’m in the middle of nowhere, many miles from power, for multiple days at a time. Then, every kWh is precious

It seems that different folks have different scenarios that concern them. Maybe it’s daily driving and the cost of VD. Maybe it’s dealing with long term storage issues. Or, maybe it‘s being able to stay off the grid for as long as possible.

2 kwh per day is 730kwh per year or 5-7 "tanks" of fuel leaking out. For most people, being able to park a car for an extended time and it having the same amount of gas upon return is just not something we've had to worry about previously. People have shipped their Rivians and had issues with the HV pack going flat or leaving on long trips returning to the airport with a much more empty battery. All of which doesn't inspire a reduction in range anxiety for people I think.

Sponsored