Solution for weak 12v battery which occurs in most hybrid vehicles and LC250 ?

Don’t mean to do free advertising for Amazon products, but share my personal experience. Here is how Super Stater helping me to monitor/alarm when power/charging is in critical. Ideally, it is always ready to start the engine when the 12v is out of the game.
Like I said in beginning of thread that I always have super duty battery jump starter, Jackery with jump starter / cables, and old-school charging cables. However, I kept plugging in and out and when couldn’t start engine ESPECIALLY in no where in woods or desert with no vehicles around (except wife and 2 kids)
Attached are some photos/video of this Super Starter. Soon, I will try to “kill” the battery by open all doors…then see how this device starts the engine (will report later)

Note: I didn’t have time to visit dealer to check the battery health yet. I personally HATE to see those dealer service advisors personally…they try to make $$$ or could cause some more problems then you come back to fix !
 

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Carista can display “battery voltage as seen by ECU” in both auxiliary and ready positions.

11.7V indicates a partially discharged battery. Normal resting voltage for a 12V flooded lead acid battery is supposed to be 12.6V, and you’ll want to see above 13V in ready position where the ECU determines charging voltage. It would be helpful to put a trickle charger on your battery before your trip.
Thanks for helping defend my trip! The 11.7 reading was the lowest seen in quite a number of readings and was not the most recent. I really didn't dwell on it after seeing more readings above 12 later and knowing that I couldn't tell you the conditions at the time of measurement.

So I just checked again as I also wanted to see what my trusty Fluke 77 would say in parallel with Carista (connected meter to the jump start points, 100% in agreement with Carista's lower resolution). Initial measurement on both was 12.3.

Booster arrived (and will be going along for the ride) but I'll stay away from my battery charger for now. Part of my lack of concern is the fact that overlanding time is preceded by over 1500 miles of highway time which BETTER negate any small starting deficit from the garage and therefore any effect the charger might have.
 
To anyone who may think this isn't a thing...I've experienced this issue with a 2021 Toyota Venza Hybrid (I couldn't even sit in the car and listen to the radio for 10 minutes without the car automatically shutting off due to a weak battery. Toyota never solved the issue.) My LC started experiencing similar problems that led to a Drive/Start Malfunction which was due to the weak battery which Toyota replaced under warranty. When I took my LC in for the battery replacement the dealer provided a 2026 hybrid Camry which also gave me the Low Battery warning and shut itself off while I was listening to the radio for fewer than five minutes. Even with the new battery, I've experienced a low battery condition that required me to jump the LC with my NOCO jump box to get it up and running (I had the doors open while I was detailing the car for 15-20 minutes.)

I've gotten in the habit of using my NOCO Genius to regularly top off the battery.
 
To anyone who may think this isn't a thing...I've experienced this issue with a 2021 Toyota Venza Hybrid (I couldn't even sit in the car and listen to the radio for 10 minutes without the car automatically shutting off due to a weak battery. Toyota never solved the issue.) My LC started experiencing similar problems that led to a Drive/Start Malfunction which was due to the weak battery which Toyota replaced under warranty. When I took my LC in for the battery replacement the dealer provided a 2026 hybrid Camry which also gave me the Low Battery warning and shut itself off while I was listening to the radio for fewer than five minutes. Even with the new battery, I've experienced a low battery condition that required me to jump the LC with my NOCO jump box to get it up and running (I had the doors open while I was detailing the car for 15-20 minutes.)

I've gotten in the habit of using my NOCO Genius to regularly top off the battery.
15-20 minutes doors opened: too long 😆 😆
Yes, brother…I have to turn on engine while detail the LC !
I have never had that kind of silly experience even with super old / regular gas cars. Hybrid is not my thing, but love LC much much so I will conquer her 😜
 
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I will check with dealer if it is still under manufacture warranty and probably it can be replaced for “free” ;)
Anyway, I hope the 2 methods I mentioned will bring a huge peace of mind while in remote/ overland
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I will check with dealer if it is still under manufacture warranty and probably it can be replaced for “free” ;)
Anyway, I hope the 2 methods I mentioned will bring a huge peace of mind while in remote/ overland
Report:
Today I brought my rig to dealer for recalls correction, and by a chance I told them my horrible story about battery and asked them to test its health.
The result is the dealer replaced it per manufacturer warranty (under 2 years /14.5k mi)
So far, per my Super Starter / Battery Monitor-Alarm…I see the battery hold juice 100% and 12.9-13 v for couple hours. So far so good, but need to observe its behavior in next couple weeks
Before, even right after I charged it 100%, the juice just quickly dropped down to 60-70% then kept going down under 50%

Anyway, even the battery is way improved, I still keep the BS200 Super Starter installed to monitor 24/7 through my phone and 100% guarantee engine can start even battery goes down to 5% juice. I still have a big/powerful jump start with me as well ;)
Man…The battery replacement cost manufacture $450.49 😜
 

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So the warrentee on battery is same as standard. 3 years or 36,000 miles?
 
Wow, this battery thing sounds like a potential for a massive headache and @dato6966 ‘s post above is a scenario that I can see easily being duplicated. Is it clear that the ANCEL Super Starter device will function and start the car if the 12V battery is badly sulphated? When batteries are that bad, trickle chargers and some (possibly most?) jump starters may not work because of their protection devices. Where is one of these Super Starters installed? I’m waiting for my LC to be delivered now so I haven’t even seen where the battery is or how much space there is around it!
 
Wow, this battery thing sounds like a potential for a massive headache and @dato6966 ‘s post above is a scenario that I can see easily being duplicated. Is it clear that the ANCEL Super Starter device will function and start the car if the 12V battery is badly sulphated? When batteries are that bad, trickle chargers and some (possibly most?) jump starters may not work because of their protection devices. Where is one of these Super Starters installed? I’m waiting for my LC to be delivered now so I haven’t even seen where the battery is or how much space there is around it!
Welcome to the asylum.
 
Wow, this battery thing sounds like a potential for a massive headache and @dato6966 ‘s post above is a scenario that I can see easily being duplicated. Is it clear that the ANCEL Super Starter device will function and start the car if the 12V battery is badly sulphated? When batteries are that bad, trickle chargers and some (possibly most?) jump starters may not work because of their protection devices. Where is one of these Super Starters installed? I’m waiting for my LC to be delivered now so I haven’t even seen where the battery is or how much space there is around it!
There is room on top of 12v battery (between battery and bottle jack). ANCEL BS200 (brick) fit well in there
 
@Lotusfan,

a better place to store a charger might be, just to the left of the jack cradle (there a pretty decent void there). I wouldn't store anything on top of a battery for fear of it might bounce and damage the lead post/terminal to plastic body seal. If the seal gets compromised, it'll allow acid vapor to contaminate the metal and electronic components located in that area.
 
@Lotusfan,

a better place to store a charger might be, just to the left of the jack cradle (there a pretty decent void there). I wouldn't store anything on top of a battery for fear of it might bounce and damage the lead post/terminal to plastic body seal. If the seal gets compromised, it'll allow acid vapor to contaminate the metal and electronic components located in that area.
Thanks for that sound advice. I’ve read some more into the ANCEL Super Starter and I’ve got a few questions now to determine if it is the best solution for the hybrid LC. Does the 12V battery in the LC power only the electronics leaving the actual starter for the ICE up to the hybrid battery? My understanding of the Super Starter is that uses capacitors to give the 12V battery a boost for the high current draw starting situation, so isn’t that quite different from powering the electronics only? I suppose that it should still work as long as it isn’t sitting there powering things for a prolonged time before starting the ICE, but if the hybrid battery is discharged doesn’t that leave you still with a no-start situation since the ICE is needed to get power into the hybrid battery. I’m leaning toward getting a bigger/better 12V battery and carrying a jump starter battery pack. I emailed ANCEL for their thoughts. It’s nuts - I don’t even have the car yet and I’m obsessing over this stuff already.
 
Thanks for that sound advice. I’ve read some more into the ANCEL Super Starter and I’ve got a few questions now to determine if it is the best solution for the hybrid LC. Does the 12V battery in the LC power only the electronics leaving the actual starter for the ICE up to the hybrid battery? My understanding of the Super Starter is that uses capacitors to give the 12V battery a boost for the high current draw starting situation, so isn’t that quite different from powering the electronics only? I suppose that it should still work as long as it isn’t sitting there powering things for a prolonged time before starting the ICE, but if the hybrid battery is discharged doesn’t that leave you still with a no-start situation since the ICE is needed to get power into the hybrid battery. I’m leaning toward getting a bigger/better 12V battery and carrying a jump starter battery pack. I emailed ANCEL for their thoughts. It’s nuts - I don’t even have the car yet and I’m obsessing over this stuff already.
Q: Does the 12V battery in the LC power only the electronics leaving the actual starter for the ICE up to the hybrid battery
A: The 12v system powers all the "normal" 12v things. The LC has two starting methods..... normally started by the Hybrid Xmsn and has a totally separate 12v conventional starter that's used when the Hybrid system fails to start the ICE.

In my case, I opted to replace the OEM 12v battery with an Optima, I carry the largest capacitor type jump box I could find and I have a C-TEK trickle charger semi-permanently to the 12v battery. Additionally I installed a solar powered 12v battery charger under the roof rack.

Even with all of that I've still managed to create a "no-start" condition on a couple of occasions, but all were self-inflicted, as I tinker on my LC on an almost daily basis.
 
Q: Does the 12V battery in the LC power only the electronics leaving the actual starter for the ICE up to the hybrid battery
A: The 12v system powers all the "normal" 12v things. The LC has two starting methods..... normally started by the Hybrid Xmsn and has a totally separate 12v conventional starter that's used when the Hybrid system fails to start the ICE.

In my case, I opted to replace the OEM 12v battery with an Optima, I carry the largest capacitor type jump box I could find and I have a C-TEK trickle charger semi-permanently to the 12v battery. Additionally I installed a solar powered 12v battery charger under the roof rack.

Even with all of that I've still managed to create a "no-start" condition on a couple of occasions, but all were self-inflicted, as I tinker on my LC on an almost daily basis.
  • In your opinion, were your no-start conditions created simply by having doors/lift gate/hood open?
  • Your recovery from the no-start condition is now what?
  • What forms has recovery taken in the past?
  • Do you think a NOCO Boost low end (GB20) connected to the under hood relay box jumper locations will enable me to recover
Thanks!
 
  • In your opinion, were your no-start conditions created simply by having doors/lift gate/hood open?
  • Your recovery from the no-start condition is now what?
  • What forms has recovery taken in the past?
  • Do you think a NOCO Boost low end (GB20) connected to the under hood relay box jumper locations will enable me to recover
Thanks!
  • In your opinion, were your no-start conditions created simply by having doors/lift gate/hood open?
Absolutely my fault! I was unaware how many systems are active on the LC when just a door is opened and when the door is left open, those systems never go into sleep mode. I suspect that when the key fob is in the vicinity of the proximity sensors those same systems never go into sleep mode. The woke systems are continuously monitoring to see if you want to do something etc........
  • Your recovery from the no-start condition is now what?
If I'm in a hurry or away from my house and the rear hatch is open or will open, I attach my capacitor type jump box to the 12v battery directly and press the start button. If the hatch won't open, I attach my jump box to the under-hood jumper point.

If I'm at home and not in a hurry, I simply plug in a extension cord to my permanently installed 110v extension cord pass-through. The pass-through cord is always connected to my C-TEK trickle charger (the trickle charger is semi perm connected to the 12v battery via a pigtail) a couple of hours and the LC will start and I disconnect the extension cord and stow the pass-through cord end.
  • What forms has recovery taken in the past?
Too many to list.....lol
  • Do you think a NOCO Boost low end (GB20) connected to the under hood relay box jumper locations will enable me to recover
Probably, you only need 12v to power on all the computers/sensors to a point where thw hybrid system take over upon starting of the ICE.

NOTE: If the battery is disconnected or (I assume) the voltage drops to near zero, it is my understanding the 12v starter is used to start the ICE vs the hybrid starter.

The pictures are for clarity, the complete Mod is covered on my build page..........

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I admire your ingenuity and even more your motivation!

I have done a couple things where I have had the doors open for several hours and so far have not experienced a no-start condition because of the battery. Working through it logically and picturing potential modes (brainstorming, these are conjecture, I'd love answers if you know 'em but...)
  • Are all doors equal? System response to driver's door is identical to RR passenger (or lift gate or lift gate glass)?
  • Key fob inside vehicle vs outside within 30'?
  • Clearly lighting can exert a strong influence (seems like flashers would be bad news?)
I'm headed out for 10 days of camping and will be watching this carefully!
 
I admire your ingenuity and even more your motivation!

I have done a couple things where I have had the doors open for several hours and so far have not experienced a no-start condition because of the battery. Working through it logically and picturing potential modes (brainstorming, these are conjecture, I'd love answers if you know 'em but...)
  • Are all doors equal? System response to driver's door is identical to RR passenger (or lift gate or lift gate glass)?
  • Key fob inside vehicle vs outside within 30'?
  • Clearly lighting can exert a strong influence (seems like flashers would be bad news?)
I'm headed out for 10 days of camping and will be watching this carefully!
  • Are all doors equal? System response to driver's door is identical to RR passenger (or lift gate or lift gate glass)?
All doors are not created equal, trim level would determine which sensors are active etc....... but all doors for each trim level should be the same, IDK for sure. The hatch seems to be separated from the passenger doors
  • Key fob inside vehicle vs outside within 30'?
You will not get a response unless you are within a few feet! 30' is wishful dreaming......lol. I think Toyota reduced the power output/range on the new models due to how easy the fob was to clone etc....

A Lot has to do with which of the Nannies you turn off/disable, interior lighting options etc........ When I first had dead battery issues, I turned off everything possible and it made a small difference. As I became more aware of how long I had the door(s) open (while working on a project) had fewer "no start" issues.

If you are going camping, disable the interior lights using the overhead console selection button, Put your FOB into sleep mode and shut the passenger doors when you're not physically getting in or out etc......... Carry a jumper box and you'll probably be just fine
 
I lifted this diagram from another thread here I believe. My understanding was that at vehicle startup the 12v starter was always used. The hybrid motor is used for star/stop during operation.

I don't personally know, just going on what I read here and elsewhere.

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