I wonder if the 12 volt battery charging problem in eco mode has been fixed for our hybrids?
Solution for weak 12v battery which occurs in most hybrid vehicles and LC250 ?
- Thread starter t3lcfe
- Start date
I wonder if the 12 volt battery charging problem in eco mode has been fixed for our hybrids?
overtrail887
Active member
Not sure if it’s the same, but I’ll throw this at the wall and maybe others have gone down the same road.
In my last suv, a qx80 we needed to do a “mod” so that the battery would charge normally. Removing a wire that went to the battery had it default to a “dumb” charging rate instead of the “smart” rate which left the battery too discharged too often.
“The fix is to disconnect the "smart" wire which runs from the IPDM to the alternator. This puts the alternator on internal regulation, so it will output 14.2V like a normal alternator.”
In my last suv, a qx80 we needed to do a “mod” so that the battery would charge normally. Removing a wire that went to the battery had it default to a “dumb” charging rate instead of the “smart” rate which left the battery too discharged too often.
“The fix is to disconnect the "smart" wire which runs from the IPDM to the alternator. This puts the alternator on internal regulation, so it will output 14.2V like a normal alternator.”
OP
OP
- Thread starter
- #23
The health of battery / battery life is critical for overlanders / off-roaders. I myself must find solution to conquer it!
Besides 2 solutions above that I will test out, here are 2 methods I currently HAD:
1/ topped-off battery whenever I have time or remember (once a while): Noco Genuine 5
2/ because of many times battery dead happened, I had Anderson Style quick connector running to the rear seat area for easier access (other than engine bay). It can be used for someone wants to get power for portable air compressor. Of course must turn on engine before use. I never need that use
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On most new era vehicles with all the electrical demands, leaving the door open is just the last straw. In winter, people live with seat heaters on full time, defrosters , the list goes on. I have owned a few vehicles with SUPPOSEDLY notorious electrical issues. 90+% of the issues are the result of chronically discharged batteries!!!! My 2 Stelvios have had ZERO issues. The reason is simple....When I will not be using them for more than a day or 2 , I simply take 15 seconds and connect to my tenders. Case dismissed. LC is covered in Maine past 2 months.....ON TENDER. While away over the holidays even the Fiat 500e will be , yup, you guessed it, ON TENDER...4C will also be on tender. Tractor battery is 13 yrs old, yup on tender while away....I have had 1 battery fail in less than 5 yrs.......all others I have replaced at 6-8yrs because I knew it was time to stop pushing my luck.....Tenders are cheap and they WORK!!! Just buy a Noco 1 or Deltran 500mV. They are slow but they do the job. Slow is better for the batteries anyway. No need for the BIG 5+ amp units Overkill.
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OP
OP
- Thread starter
- #25
I owned many vehicles till now in my life, but LC is the 1st hybrid one. Never had to deal with small and weak battery like this. I love and happy with LC and definitely will conquer her
. For sure 
Function of the 12V battery in a hybrid differs little from any other vehicle including a true EV. Our current generations apparent need for electronic everything in their vehicles is making this an industry wide problem. Frequent any brand forum..it's a thing! The brains in an EV use the 12V supply. left unattended, they cause fun issues too. My Fiat will be on tender Thursday...........takes a long time to fully recharge sometimes...
The 12vdc battery in EVs and hybrids is initialy used to verify it is safe to turn on the "switch" for the traction battery output. Various checks are performed prior to connecting traction battery, i.e. all the orange cables are properly connected.
On but not running, driver door open-
Later after closing doors, turn to off but before full power down
Later after closing doors, turn to off but before full power down
I had the 12V battery fail this winter when it was minus 35C. My LC was about 18 months old at that point. I figured no problem - I'd use my jump starter - so hooked it up & hit start only it didn't start - wouldn't turn over - instead got a message to see dealer. Got out the manual and soon discovered that there was probably a low voltage issue so the system basically shut down to prevent damage to the electronics. Called Toyota assist & they dispatched a tow truck. Tow driver figures no problem he'll jump start it - Nothing - so he will load it on the tow truck & haul it to the dealer. Hooked it up and was about to pull it onto the deck except the e-brake on my LC wouldn't release as the 12V battery was dead. When he was about to drag it on with the e-brake engaged I intervened & told him I wanted a dolly as dragging it could do damage. Next tow truck came with a dolly - EXCEPT - it was for a car and the LC weighed too much to haul it any distance. Called another tow truck - so finally after 3 tow trucks and waiting in munis 35C weather, it got to the dealership. It was a sulphated 12V battery which was replaced under warranty. At this point I'm totally annoyed with Toyota as I've discovered that I can't leave it at the airport when I travel for a week on business as the battery is then dead when I return so now I leave it at home on a charger. I also take it into remote areas fishing and now I'm hesitant that I get the low voltage lockout as the nearest Toyota dealer could be well over 500km away. In the summer maybe a small solar panel is a solution as long as it's not the airport parkade - but winter is an issue. The BS200 sounds like a possible solution
Seen as you offroad types have a laundry list of stuff you carry, sounds like a spare Group 48 battery would be a nice compact thing to have.......or a wicked long extension cord, hehe
OP
OP
- Thread starter
- #31
Just received my unit. However I need to check the battery with dealer 1st so didn’t install BS200 yet.
As “alone” overlanders and especially with this hybrid LC, definitely I will install it as extra “insurance/peace of mind” when we are in woods or desert ourself even though if dealer replace the new battery for me. Jump starter is still kept permanently inside the rig for alternative backup for ourselves or for saving others got stranded in no where
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Here is a inexpensive solution to keep in your rig...
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Jump Starter, 5000A Battery Jumper Starter Portable, Car Battery Jump Starter, Power Booster Pack 12V Lithium Jump Box with Jumper Cable and LED Lights (All Gas / 12L Diesel Engines)
4.24.2 out of 5 stars
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600+ bought in past month
Price, product page$29.06Typical price: $30.59
Typical price: $30.59
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Thanks for sharing this. Now I am not looking forward to next winter when it regularly goes below -35C at night. I will start preparing for winter well ahead now.
I assume you had the block heater plugged in?
Exactly - that video is some superb hyperbole.
Fundamentally on Toyota cars & small SUVs the Toyota Hybrid Synergy Drive is the powertrain using a eCVT designed for maximum efficiency. While the IFORCE-Max is a parallel drive hybrid system integrated between the engine & transmission providing supplemental torque & HP for power, towing & off-roading.
Seems these videos are just YouTube click bait sensationalizing issues into incorrect info & AI not at its best. Feeds a generational change in ownership with so many having never opened a hood, changed a tire or their oil, then add in lots of new vehicle technology & this ownership thing can be overwhelming. These dramatic videos drive bad info. I appreciate this forum as it collects lots of good info for DIY & engaged owners, & also for visitors just looking for answers.
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And of course, chronically discharged batteries are more prone to failure...esp in extreme cold. I prefer -31F .........to 100F
Metrosexual was a term 10-15yrs ago.....it has only gotten worse.
This thread had me a little spooked about leaving my rear hatch open for extended periods. I have left the hatch open for hours with no ill effects in the past but never checked the SOC of the battery aftwerwards.
I did not have an extra shunt laying around so I did not check the drain when the hatch was open. However, my battery is the factory lead acid Toyota OEM battery so checking the SOC using the voltage is fairly reliable.
Yesterday I opened my rear hatch and checked the battery voltage. It was 12.6 volts. It's a 2 year old battery abused by our extreme heat out here in AZ so this seamed good. I had just measured 12.7 volts a few days earlier so this is right in the ballpark.
After leaving the hatch open all day (10 hours) I checked the voltage. Still 12.6 volts. There was no appreciable drain on the battery.
For those having issues, do you have the optional hatch lights? I do not. I did install an aftermarket hatch light but it switched off after some time.
-Curtiss
I did not have an extra shunt laying around so I did not check the drain when the hatch was open. However, my battery is the factory lead acid Toyota OEM battery so checking the SOC using the voltage is fairly reliable.
Yesterday I opened my rear hatch and checked the battery voltage. It was 12.6 volts. It's a 2 year old battery abused by our extreme heat out here in AZ so this seamed good. I had just measured 12.7 volts a few days earlier so this is right in the ballpark.
After leaving the hatch open all day (10 hours) I checked the voltage. Still 12.6 volts. There was no appreciable drain on the battery.
For those having issues, do you have the optional hatch lights? I do not. I did install an aftermarket hatch light but it switched off after some time.
-Curtiss
Hatch lights, door curtesy lights, mirror puddle lights and interior foot well lights, some or all come on with a door open/hatch open or proximity of the key fob. Most can be disable etc....... but what's the point of having them if they're always in the off position. Additionally the proximity brain is always checking to see if FOB is in range (not really but that's the best way to explain it) all of which causes a parasitic drain 0n the 12v battery system.
It appears to me that some owners don't have a big issue with the battery as others and this may be due to a good OEM battery from day one. It does make me wonder if there is a setting/spec for the inverter that would allow an increased charge rate, IDK and haven't been able to locate any information concerning this subject.......
My 25 Premium seems to have most of the courtesy lights including the lift-gate lights and in 6 months / 13K+ miles I have had no problems with the original battery. The lift gate lights have a switch mod on them and they basically stay off. The vehicle is garaged except when out of town but did see 4 days of subzero to 20 temperatures when it was a month old. I (am and) have checked state of charge a few times (but used Carista to read OBDII info to read which means ignition was on- not sure I can read with it off), 11.7V is the lowest reading I've observed and the vehicle started no problem.
The LC will be doing its first honest overlanding very soon where a failure would be extremely inconvenient. Normally I would think that would be all that was needed to manifest a dead battery in the least convenient place but this discussion scared me and I bought a booster. This virtually guarantees that I won't need it and everything will run fine?
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.
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