Phantom / Vampire Drain Solution Works! Using 12v Battery Tender

[SadHill]

Good morning, I saw this thread when it first was posted. I decided to try it. Took 3 weeks for Amazon to ship the adapter which I received yesterday. I plugged it in last night and it doesn’t show charging. It does show a green light but it doesn’t show trickle or charge.
I went from 223 of range last night to 218 now (was 219 a hour ago). My truck is in my garage which is 50+’ away. No way for it to wake up as I am not near it. Plus it doesn’t lock at home.
Any help would be appreciated. Thx

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[DayTripping]

it would be helpful to post what year and model truck you have, as well as what things you ordered exactly. Did you order the battery tender OBD connector?

I assume you got the clarity right, but did you check to make sure there was output from the battery tender itself? I got one not long ago that didn’t work even though it said it was.

 

[SadHill]

it would be helpful to post what year and model truck you have, as well as what things you ordered exactly. Did you order the battery tender OBD connector?

2022 launch with dual batteries.
Purchased exactly what was linked in this thread.
Omg. I just went out there and unplugged it all and then plugged it back in and now it says charging!
what a dork I am. I must not have had it tight enough.
sorry all!

 

[DayTripping]

Thanks for letting us know and it helps to be a reminder for everyone to double check their connections.

 

[MacO512]

Yes. I am using a Noco Genius 1 (1 amp) connected through the OBDII port. It is a charger + desulfator. I played it very conservative by going with the 1 amp model. But other posts in this forum state you can charge up to 3 amps through the OBDII port. I didn't want to take any chances.
I haven't used this setup very long on the Rivian so I can't give you any concrete results. But I've been using a charger/desulfator on an aircraft battery for a few years with excellent results. I had been replacing very expensive AGM aviation batteries every 2 years because of the amount of down time. I think I'm at 4 or 5 years now on the same battery since I started using the desulfator. It made a believer out of me.

I just ordered the battery tender 3 amp model

https://www.amazon.com/dp/B016S7NHW...ref_=cm_sw_r_cp_ud_lstpd_CHZNNJ8AQSMPCFPTZTD3

However now I'm wondering if I should get a different tender with a desulfator? From what I can tell the battery tender model does not have this feature. Sounds like that could be a big benefit for long term 12v health.

 

[MacO512]

I see this Noco tender has a desulfinator. Maybe 2amp is a bit easier on the OBD port. I like that it can trickle other Lifepo batteries i have too. Only thing I wish is it had an SAE port to more cleanly connect to the OBD cable.

https://www.amazon.com/dp/B07W6B987...ref_=cm_sw_r_cp_ud_lstpd_SMEKHJ5SQ2Z68EP9MZ0P

 

[DayTripping]

I see this Noco tender has a desulfinator. Maybe 2amp is a bit easier on the OBD port. I like that it can trickle other Lifepo batteries i have too. Only thing I wish is it had an SAE port to more cleanly connect to the OBD cable.

https://www.amazon.com/dp/B07W6B987...ref_=cm_sw_r_cp_ud_lstpd_SMEKHJ5SQ2Z68EP9MZ0P

I use that on some of my motorcycles and constantly regret that I didn't get one with an SAE connector so I could have just put ring terminal connectors on the batteries with an SAE plug. Awesome device other than that. I am just too lazy to cut it apart and wire on an SAE connector so bought a different multi battery one insteated and still use this one occasionally for things like the riding mower or jetskis.

 

[MacO512]

I use that on some of my motorcycles and constantly regret that I didn't get one with an SAE connector so I could have just put ring terminal connectors on the batteries with an SAE plug. Awesome device other than that. I am just too lazy to cut it apart and wire on an SAE connector so bought a different multi battery one insteated and still use this one occasionally for things like the riding mower or jetskis.

Yeah, I'd like to stick to a name brand like Noco or battery tender. Surprised the battery tender one doesn't have a desulfinator, unless they just aren't listing the feature. They say it's a "maintainer". Sure I could splice on an SAE but seems like somebody should sell one I don't have to.

 

[SSteveEV]

I use that on some of my motorcycles and constantly regret that I didn't get one with an SAE connector so I could have just put ring terminal connectors on the batteries with an SAE plug. Awesome device other than that. I am just too lazy to cut it apart and wire on an SAE connector so bought a different multi battery one insteated and still use this one occasionally for things like the riding mower or jetskis.

Damn, just realized my 1amp version of this Noco also doesn't have SAE plug either. Guess I'll be using my larger Battery Tender ones. Thanks Costco for making those so cheap I have about 5 of them now

 

[jfoonly]

Sure I could splice on an SAE but seems like somebody should sell one I don't have to.

I was looking at this one, currently a "big spring deal" fwiw: B0756PV96N

 

[Aardvark]

Yes. I am using a Noco Genius 1 (1 amp) connected through the OBDII port. It is a charger + desulfator. I played it very conservative by going with the 1 amp model. But other posts in this forum state you can charge up to 3 amps through the OBDII port. I didn't want to take any chances.
I haven't used this setup very long on the Rivian so I can't give you any concrete results. But I've been using a charger/desulfator on an aircraft battery for a few years with excellent results. I had been replacing very expensive AGM aviation batteries every 2 years because of the amount of down time. I think I'm at 4 or 5 years now on the same battery since I started using the desulfator. It made a believer out of me.

UPDATE: If I were doing this over, I would go with a 2 amp or 3 amp Noco tender. After using my 1 amp version, connected through the OBDII port, for over a week, this unit will not fully charge the battery. Even with charging sessions greater than 24 hours, the indicator stays red, which means less than 75 % charged.
I tested this on a spare AGM car battery, and it quickly charged to the "green", so the tender is working.
One measurement that has me confused is that if I disconnect the tender after a long charge, wait 12 hours, I am measuring 12.6 volts through the OBD. This is in the range of a fully charged, 12 V, AGM.
My conclusion is that I either have a failing battery (Sep 2023, 30,000 miles), or there is a continuous drain on the battery thay exceeds 1 amp.
Even though the tender never indicates a full charge, I am seeing zero vampire drain over periods that have reached 2 days.

 

[d15b7]

I’d say you hit the nail on the head; I bet that a sleeping R1 is using close to 1 amp and that’s why it never indicates green (but your vampire drain is negated).

as was said, I’d be very curious to know if a 2amp was sufficient to catch up and indicate green overnight

(mine is a ‘22 R1T so has dual 12v batteries. I’m at 39k miles on the original batteries but it’s definitely waking up nightly to charge them. My vampire drain is 2-3 kwhr per 24 hrs). I drive it almost every day for 50-100 miles.

 

[FooF]

I have a 2022 R1S and yesterday plugged in a 800ma Battery Tender charger with Battery Tender OBD2 charge adapter. R1S has been sleeping for 16 hours so far and no vampire drain. Lately I have been seeing 4-6 hours of sleep and ready state for 2 to 3+ hours. I have a green light on the Battery Tender.

Here is what I am using.
Battery Tender Water Resistant 12 Volt Battery Charger and Maintainer: Automatic 12VBattery Tender Water Resistant 12 Volt Battery Charger and Maintainer: Automatic 12V Battery Charger and Maintainer for Motorcycle, ATV, and Personal Watercraft - 12 Volt, 800mA Battery Float Charger - 022-0150-DL-WH

Battery Tender OBDII Adapter Cable for 12V Battery Charging - 22 Inch Cord - Solar Compatible - Charge Vehicle's 12V Battery Through OBD II Port - 081-0154-DL

 

[Aardvark]

UPDATE: If I were doing this over, I would go with a 2 amp or 3 amp Noco tender. After using my 1 amp version, connected through the OBDII port, for over a week, this unit will not fully charge the battery. Even with charging sessions greater than 24 hours, the indicator stays red, which means less than 75 % charged.
I tested this on a spare AGM car battery, and it quickly charged to the "green", so the tender is working.
One measurement that has me confused is that if I disconnect the tender after a long charge, wait 12 hours, I am measuring 12.6 volts through the OBD. This is in the range of a fully charged, 12 V, AGM.
My conclusion is that I either have a failing battery (Sep 2023, 30,000 miles), or there is a continuous drain on the battery thay exceeds 1 amp.
Even though the tender never indicates a full charge, I am seeing zero vampire drain over periods that have reached 2 days.

Long Term Test Update 4/11/2025:
I had my Gen 1 R1S parked in my garage for 13 consecutive days while traveling. Gear Guard was "Off at Home" and I did not use Shipping Mode. My 1 amp NOCO battery tender was plugged into the OBDII port. Temperatures were in the 50s (deg F). I remotely checked the status only 1 time.
I lost 9% (11.9 KWh) over this period. This averages to 0.69% per day, or 0.92 KWh per day.
While this is far below some of the horror stories on the forum of 2 to 4% per day, I have to say that I was disappointed. With the battery tender connected, I was hoping for something around 0.1% per day.
I am still baffled as to why my NOCO charger/tender never goes green, indicating a fully charged battery. It was still red after 13 days connected to a sleeping vehicle. Even though others on the forum have had good luck with similar 1 amp tenders, I may still invest in a 3 amp unit and see if I get different results.
It's also possible that my tender is working exactly as designed, and something in my vehicle is causing 12 V battery drain in excess of 1 amp.
More to follow....

 

[MacO512]

Long Term Test Update 4/11/2025:
I had my Gen 1 R1S parked in my garage for 13 consecutive days while traveling. Gear Guard was "Off at Home" and I did not use Shipping Mode. My 1 amp NOCO battery tender was plugged into the OBDII port. Temperatures were in the 50s (deg F). I remotely checked the status only 1 time.
I lost 9% (11.9 KWh) over this period. This averages to 0.69% per day, or 0.92 KWh per day.
While this is far below some of the horror stories on the forum of 2 to 4% per day, I have to say that I was disappointed. With the battery tender connected, I was hoping for something around 0.1% per day.
I am still baffled as to why my NOCO charger/tender never goes green, indicating a fully charged battery. It was till red after 13 days connected to a sleeping vehicle. Even though others on the forum have had good luck with similar 1 amp tenders, I may still invest in a 3 amp unit and see if I get different results.
It's also possible that my tender is working exactly as designed, and something in my vehicle is causing 12 V battery drain in excess of 1 amp.
More to follow....

If it's never going green your battery is never getting full. 1 amp is only 12 watts, although over 24 hours that is 288 Wh....I want to say I think mine was closer to using 400Wh a day but I'm not sure. Yeah will be curious how 3amp charger changes your results. Even 2 amp charger might be enough.

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