12v battery dead

[L-2]

I've got a few rechargeable jump starters; one in each vehicle.

NOCO GB40 and a GB70. My GB70 unit is older and doesn't have a USB-C charging input. My GB40 is newer and does have a USB-C input. It's my understanding USB-C is a later standard and may decrease recharge time a bit. I suspect all the latest and newer NOCO starters have the USB-C inputs now.
https://www.amazon.com/s?k=NOCO&crid=376BGX5ONF9Y6&sprefix=noco,aps,256&ref=nb_sb_noss_1

I also have a brand called "TYPE S", a model which is likely discontinued by now and I probably bought at Costco (brand's products still listed on Costco website).
https://typesauto.com/collections/p...g6Dn6Y20kJc9UNzG3iT3LGZpHFGCIobrL1_UlfTGwYPHs

My NOCO jumpers are in my '14 Acura MDX and '17 Tacoma. I have the TYPE-S in my '25 4Runner Trailhunter. I've used these jump starters on various vehicles, not necessarily my vehicles, over the years. I've also bought a NOCO charger with selectable modes for lead-acid, AGM, and even gel type (I think I have such a gel battery in my home alarm system).

Side note, I first saw and decided on the NOCO brand when a AAA tow truck driver personally used to jump start our MDX. I also own a couple of Battery Tender units but haven't used them lately due to dropping from 4 to 3 owned vehicles and just forgetting to put them onto our vehicles before leaving them for a week or so at a time.

For my '25 Trailhunter 4Runner, I left it parked for a month after bringing it home before getting around to making it my primary vehicle. The manual is just so large and with the 4Runner having so many features/systems which were new for me to operate.

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[bakutheleo]

I have had my ORP Hybrid sit for maybe 2 weeks once without a problem. All the other comments are good though--there is power drawn from a lot of electronics--not much, but adds up over time. Also, as I recall when I looked at the 12V battery, it is pretty tiny, so probably not a very high capacity as it is when it usually is when used for a starter battery.

If you decide to replace it with a batter with another chemistry (such as LiFePO4) make sure it is rated as a drop-in replacement, as their basic charge profiles are different so probably need more smarts" to charge properly.

 

[fishge]

I know I am definitely going to go and buy a battery boost/lithium pack for on the road so I dont get stranded... Any recommendations?

based off these reviews i went with a Gooloo. They go on sale all the time on walmart canada, probably even cheaper in the US

 

[THNC6G]

Another vote for NOCO. I also have the padded protective hard shell storage case which is much better than the included cloth bag.

My Noco just arrived this afternoon, so will get it charged tonight...

 

[ScoMay]

We have 2 Hybrids…24 Tundra TRD Pro and the 25 4Runner ORP…both have the separate 12V battery tucked away in the back in their own compartment. Although we use ours regular but not excessive….sometimes it may be 10-14 days between use. Both manuals have shown the dedicated jump site under the hood and the RED terminal under closed box.
Has anyone used a Battery Maintainer (I.e. Battery Tender) on their hybrid for extended non-use? I was told the single 12 V battery in each hybrid is for ECM and a few electronics but not for starting…the hybrid batteries take care of that…

I am also interested in this question.

Hybrid owners: If the hybrid batteries start the engine does that mean that connecting a maintainer/tender to that jump start boost post would NOT work to charge/maintain the 12v battery?

In other words, is that post bypassing the 12v battery altogether in a jump start?

I admit to being confused by some of the responses I have seen regarding this.

I want to hook up a maintainer to the 12v battery during prolonged down time. I could connect directly to the 12v battery’s posts in the rear cargo area, but was concerned about battery off gassing in the interior. Yes, I know there is a vent tube, but did not want to rely solely on that if there is a better (safer&easier) way to reach the 12v battery.

 

[Archer]

I am also interested in this question.

Hybrid owners: If the hybrid batteries start the engine does that mean that connecting a maintainer/tender to that jump start boost post would NOT work to charge/maintain the 12v battery?

In other words, is that post bypassing the 12v battery altogether in a jump start?

I admit to being confused by some of the responses I have seen regarding this.

I want to hook up a maintainer to the 12v battery during prolonged down time. I could connect directly to the 12v battery’s posts in the rear cargo area, but was concerned about battery off gassing in the interior. Yes, I know there is a vent tube, but did not want to rely solely on that if there is a better (safer&easier) way to reach the 12v battery.

I believe you could also use the "under the hood jump posts" to connect a tender. That doesn't address your question on off gassing
(don't think its' a concern) but is more convenient.



.

 

[wavejd]

+ one for NOCO - great product

I have had a related problem but I'm not sure if it is the 12v battery or not (don't mean to hijack the thread) I have left my ORP Hybrid outside for 2+ week stretches 3 different l times this winter (work travel away from the cold in the Boston area). Each time I come back, the remote start never works, including from the mobile app (just times out). A normal key start works fine. I really wish they would add a battery health indicator to the mobile app. If they can get the tire pressure (see photo) from the 4R, why not the battery level? If the app could just provide the battery level, then if one was remote from the vehicle and got an alert about a low battery, one could remote start it to potentially charge it up.

 

[VasWander]

We have 2 Hybrids…24 Tundra TRD Pro and the 25 4Runner ORP…both have the separate 12V battery tucked away in the back in their own compartment. Although we use ours regular but not excessive….sometimes it may be 10-14 days between use. Both manuals have shown the dedicated jump site under the hood and the RED terminal under closed box.
Has anyone used a Battery Maintainer (I.e. Battery Tender) on their hybrid for extended non-use? I was told the single 12 V battery in each hybrid is for ECM and a few electronics but not for starting…the hybrid batteries take care of that…

The night I drove my 4Runner home from the dealership the first thing I did is was charge the 12V battery as I assumed it had been sitting on the lot. The Owners Manual instructions were easy and it charged up just fine. I wish Toyota provided SOC (State Of Charge) dashboard info on the 12V & traction batteries that would help a lot.

 

[bakutheleo]

It does show the charge status on the dashboard if you configure it to do so (I am assuming you mean the dashboard on the vehicle--if you mean the app, I agree--it could, and should, show more info.

 

[gmarcucio]

We have 2 Hybrids…24 Tundra TRD Pro and the 25 4Runner ORP…both have the separate 12V battery tucked away in the back in their own compartment. Although we use ours regular but not excessive….sometimes it may be 10-14 days between use. Both manuals have shown the dedicated jump site under the hood and the RED terminal under closed box.
Has anyone used a Battery Maintainer (I.e. Battery Tender) on their hybrid for extended non-use? I was told the single 12 V battery in each hybrid is for ECM and a few electronics but not for starting…the hybrid batteries take care of that…

The way I understand it is, you are correct in saying the electric motor is responsabile for starting (cranking) the ICE engine. But, it depends on a strong 12 volt battery to enable the systems electronic control modules, relays, and solenoids, to do so. The hybrid battery keeps the 12 volt battery charged during normal operation, and so does the alternator if it needs to. During extended vehicle storage, the vehicle is not being driven to be able to regenerate electricity from drivetrain regeneration and engine power to maintain adequate charge in the hybrid battery for the hybrid battery to be able to maintain adequate charge in the 12 volt battery. Because of the normal parasitic draw on the 12 volt battery from just sitting for a long period of time and not being adequately charged from the hybrid battery, it gets run down and not able to energize the electronics needed to operate the vehicle electric motor to start the ICE engine. The 12 volt battery also operates all of the 12 volt componets on the vehicle such as wipers, headlights, heater motor, windows, etc. I could be wong, but this is the way I believe it works. Feel free to correct me if I'm wrong.

 

[Nodak]

the interior 12v batteries are special vs the conventional under hood 12v batteries.

the interior one have a different part number since they are required to have vent hose to vent to outside the off gassing of the battery.

if you look at the interior battery you can see a special vent tube on them to connect to the exterior venting tube

 

[Nodak]

also the 12v is to help maintain standby power for all the computers and settings, etc.

the battery pack is solely for the engine use

you could have fully charged battery pack but if the 12v is dead, none of the computers will fire up to get around the safety interlocks if i remember correctly.

caveat : unless you have the aux switch bank to charge the battery directly, otherwise the 12v does get charged by the hybrid system indirectly but its only a 1 way street in that regards. the 12v can never power the hybrid system to start the engine from my understanding.

 

[ToYoDaMan]

All is true with my Toyota Prius Hybrid System.

 

[gmarcucio]

the interior 12v batteries are special vs the conventional under hood 12v batteries.

the interior one have a different part number since they are required to have vent hose to vent to outside the off gassing of the battery.

if you look at the interior battery you can see a special vent tube on them to connect to the exterior venting tube

Yes you're correct, 12 V battery being located in the passenger compartment requires a vent hose connected to the battery vent port to route the gasses outside. Probably the main difference with the battery being a different part number is the CCA (cold cranking amp) rating of the battery. From what I read, our 4 Runner hybrid system has a conventional starter that is mainly used for cold start up and a back up in the event of a Hybrid battery failure. So you would need a higher amp rated battery to crank over the gas engine utilizing the conventional 12 volt starter motor. When I have my TRD Pro on the lift I'm going to be looking for that 12 V starter to verify. I wasn't aware our Hybrid system had a conventional starter.

 

[gmarcucio]

also the 12v is to help maintain standby power for all the computers and settings, etc.

the battery pack is solely for the engine use

you could have fully charged battery pack but if the 12v is dead, none of the computers will fire up to get around the safety interlocks if i remember correctly.

caveat : unless you have the aux switch bank to charge the battery directly, otherwise the 12v does get charged by the hybrid system indirectly but its only a 1 way street in that regards. the 12v can never power the hybrid system to start the engine from my understanding.

Here is what my search revealed about the 12V battery in our 4 Runner Hybrid system being able to crank over the gas engine without the Hybrid battery. I didn't know our Hybrid system had a 12 volt conventional starter.



Based on the design of the 2025 Toyota 4Runner Hybrid (i-FORCE MAX), yes, the 12-volt battery is capable of starting the gas engine even if the high-voltage hybrid battery fails, due to the inclusion of a conventional starter motor.
Unlike some older Toyota hybrid systems that rely entirely on the high-voltage battery and electric motor to start the engine, the 2025 4Runner hybrid utilizes a setup similar to the Tundra Hybrid and Tacoma Hybrid, which includes a conventional 12-volt starter for specific conditions.

• System Design: The 2025 4Runner Hybrid utilizes a 2.4L turbocharged engine with a 48-hp electric motor integrated into the transmission, creating a "parallel" hybrid system rather than a "series-parallel" system found in a Prius.
• Engine Starting: While the hybrid system normally starts the engine, the vehicle includes a conventional starter motor used for cold starts, very low hybrid battery levels, and, crucially, as a backup.
• 12-Volt Dependence: If the high-voltage battery (traction battery) fails, the 12-volt battery still powers the computer systems necessary to engage the starter and fire the gas engine.
• Limitations: If the 12-volt battery is completely dead, the car will not start, just like a traditional car. However, if the high-voltage battery is the failure point, the 12-volt system can typically still start the gas engine to allow you to drive, although likely in a "limp mode" with reduced performance.

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