Changing 12v Battery

[basicxj]

I am thinking a drilled block of HDPE (the material self healing cutting boards are made of) of the correct height and a longer cap bolt of the correct size/thread would allow re-using the factory battery hold down with the new Odyssey. HDPE is strong, easy to cut and drill, has a little bit of cushion. I have used it to make automotive speaker mounting baffles.

Measure the difference in height of the two batteries and if you can’t find a cheap cutting board of the correct thickness, a local plastics supplier may have some offcuts for cheap or free.

 

[RUN-8]

Yes, a bit more power. This was my OEM battery --> 380LN3-MFView attachment 56244

600 CCA is pretty slim in cold weather, although all it really needs to do is be able to power on the computers that boot up the hybrid battery and the ECU along with some other computers, at least under normal circumstances.

I know from experience that a weak battery will make all those computers mad as hell, and things will not work right at all.

This early in most of these batteries life I think the culprit is just bad batteries that are weak and don’t make full voltage to start with and when it gets cold they fall even lower to the point the computers will not even work right.

Putting in an identical or near enough identical sub par battery has a higher likelihood of similar failures.

Funny enough a video just dropped about something similar on a Lexus ES300 Hybrid.

 

[D-Train]

I know I'm jinxing myself.. I haven't had any issues on the OEM 12v battery. Year and half of ownership and ~11K on the clock. I do have a NOCO jump box I keep charged and leave it in the LC. I don't have any Toyo app services, and I disabled the DCM. I don't have any other aftermarket kit setup on the 12v system either. My guess is all that stuff running when the LC is parked doesn't help matters.

I know folks are upset at this, but it would seem a lot of hybrid vehicles suffer from this issue. I had an older Nissan Leaf (full EV/commuter car) years ago, and the 12v battery issue was roughly the same as the LC now. I did fix that with an AGM 12v replacement.

I have been eyeballing an Optima Yellowtop swap. I may just wait until the OEM takes a poop. I know EOD guy did one? Anyone else on here swap one in with good results for the last 6-12months? TIA!

 

[Mikie]

I know I'm jinxing myself.. I haven't had any issues on the OEM 12v battery. Year and half of ownership and ~11K on the clock. I do have a NOCO jump box I keep charged and leave it in the LC. I don't have any Toyo app services, and I disabled the DCM. I don't have any other aftermarket kit setup on the 12v system either. My guess is all that stuff running when the LC is parked doesn't help matters.

I know folks are upset at this, but it would seem a lot of hybrid vehicles suffer from this issue. I had an older Nissan Leaf (full EV/commuter car) years ago, and the 12v battery issue was roughly the same as the LC now. I did fix that with an AGM 12v replacement.

I have been eyeballing an Optima Yellowtop swap. I may just wait until the OEM takes a poop. I know EOD guy did one? Anyone else on here swap one in with good results for the last 6-12months? TIA!

I replaced my OEM battery with an Optima Yellowtop (same one as EOD_Guy) March 5th of last year (2025). I definitely haven't had any problems with it per se, but I still have a problem with my battery level dropping (what I think is) excessively and relatively quickly, often leaving me in the 12.2 to 12.3V range if I don't act to charge it. I suspect that the AGM can provide more juice than the OEM flooded cell, but I have no way of knowing for sure, as I can't compare them.

That said -- I'm optimistic that the disconnect of the battery sensor (as discussed in another forum entry) will resolve my battery drain problem, or at least mostly so. If I can keep my AGM fairly well charged, using only the native recharging capability of the LC, then I think I'll be OK.

 

[bluescruiser]

600 CCA is pretty slim in cold weather, although all it really needs to do is be able to power on the computers that boot up the hybrid battery and the ECU along with some other computers, at least under normal circumstances.

I know from experience that a weak battery will make all those computers mad as hell, and things will not work right at all.

This early in most of these batteries life I think the culprit is just bad batteries that are weak and don’t make full voltage to start with and when it gets cold they fall even lower to the point the computers will not even work right.

Putting in an identical or near enough identical sub par battery has a higher likelihood of similar failures.

Funny enough a video just dropped about something similar on a Lexus ES300 Hybrid.

That’s makes the most sense out of anything I’ve seen in this topic as it reflects my experience perfectly.

I don’t always have the option to plug in my block heater, so I need a battery that is the least likely to leave me stranded

 

[t3lcfe]

I used this device to test my OEM battery this morning. Here are the results.
I am on the edge of replace the OEM battery or not…(don’t want to waste thing)

Looks like it is still okay (?). Just carefully closing doors, turning off lights while working on LC. As you can see, the CCA test shows less than 600
Seems that in hybrid vehicle, the battery is never allowed to have 100% charge…so battery can run out very quick ! New battery is not 100% safely because of the hybrid system design ! (Of course still much better)

Also, I learned that hybrid system does not require high CCA. Is it correct ? Please educate me Thanks much

 

[D-mac]

I believe I was comparing dimensions of Odyssey's Group 48 against the Optima DH6 that EOD Guy says is a known good fit.

Width/length/height of the group 48 choices seem to be within a mm or two. The ODX-AGM27F has stronger specs but seems larger.

Group 48 and H6 are two ways of referring to the same battery size. One is European and the other is US.

 

[D-mac]

Looks good.
OEM battery CCA 600A vs. CCA 760A Odyssey battery (ODP-AGM48 H6 L3)

I noticed XS Power D4800 AGM has 836 CCA. It's probably not available at your local auto parts store, but is available online from many sellers. They seem to have a good reputation for car audio and performance builds.
The group 48 lithium batteries deliver over 1000 cranking amps if they don't go below freezing (through internal/external heaters).

 

[RUN-8]

I used this device to test my OEM battery this morning. Here are the results.
I am on the edge of replace the OEM battery or not…(don’t want to waste thing)

Looks like it is still okay (?). Just carefully closing doors, turning off lights while working on LC. As you can see, the CCA test shows less than 600
Seems that in hybrid vehicle, the battery is never allowed to have 100% charge…so battery can run out very quick ! New battery is not 100% safely because of the hybrid system design ! (Of course still much better)

Also, I learned that hybrid system does not require high CCA. Is it correct ? Please educate me Thanks much

The hybrid system should not require high CCA or CA under normal circumstances.

As noted in a Google search CCA is the ability of a battery to crank/start an engine in 0F for 30 seconds while maintaing at least 7.2V.

With that in mind it appears your battery is healthy, it’s still putting out 14+volts under load and should be more than capable of maintaining minimum voltage to power up control computers to start off the hybrid motor generator as per normal.

Guys in much colder climates may very well want more reserve especially with the super conservative charging schedule Toyota uses for these batteries. That way when it gets really stupid cold and the hybrid battery drops below operating temp and kicks things off to the conventional starter there’s enough CCA there to get the party started.

 

[t3lcfe]

The hybrid system should not require high CCA or CA under normal circumstances.

As noted in a Google search CCA is the ability of a battery to crank/start an engine in 0F for 30 seconds while maintaing at least 7.2V.

View attachment 56265

With that in mind it appears your battery is healthy, it’s still putting out 14+volts under load and should be more than capable of maintaining minimum voltage to power up control computers to start off the hybrid motor generator as per normal.

Guys in much colder climates may very well want more reserve especially with the super conservative charging schedule Toyota uses for these batteries. That way when it gets really stupid cold and the hybrid battery drops below operating temp and kicks things off to the conventional starter there’s enough CCA there to get the party started.

Thank you very much for all detail information. It’s not only useful for me but also for all members.
Happy New Year to you and All !

 

[PixelMagic]

Easy 9V battery setup to protect Powertrain Control Module Memory when changing the battery:

 

[sweet5ltr]

Easy 9V battery setup to protect Powertrain Control Module Memory when changing the battery:

Great, but I wouldn't consider doing this on my LC. Maybe a 1995 Ford Taurus. There have been hundreds of thousands of batteries changed without an issue. Even plugging a device into the OBD-II port can cause all sorts of problems with these modern electronics.

I did notice that with the LC in park today while finishing up my winch install, it was charging at 14.4V. I also noticed that the OEM battery is pretty weak, 600 CCA or something along those lines with a 70Ah reserve capacity. I'm probably going to need to upgrade this, sooner than later, for my winch.

 

[virginia-john]

Is this the right Odyssey battery? (price seems pretty good): https://www.amazon.com/Odyssey-Batt...ormance/dp/B08MWVCL9F?tag=landcruiserforum-20

Also, which is the right choice: top post terminals "A" or "B"...? (I have a suspicion it doesn't matter, it doesn't need either, the LC just connects to the bare post, so any top post terminals included w/ the battery are unnecessary.... please confirm!)

 

[basicxj]

Is this the right Odyssey battery? (price seems pretty good): https://www.amazon.com/Odyssey-Batt...ormance/dp/B08MWVCL9F?tag=landcruiserforum-20

Also, which is the right choice: top post terminals "A" or "B"...? (I have a suspicion it doesn't matter, it doesn't need either, the LC just connects to the bare post, so any top post terminals included w/ the battery are unnecessary.... please confirm!)

If you want “drop in” with no modifications required to secure the battery hold down, you are probably going to want the H6/Group 48 version.

 

[Mikie]

...and you definitely want top posts if you want ease of installation -- the wire connector points from the car are designed to fit a top post battery...

 

[WeGo250]

I replaced my OEM battery with an Optima Yellowtop (same one as EOD_Guy) March 5th of last year (2025). I definitely haven't had any problems with it per se, but I still have a problem with my battery level dropping (what I think is) excessively and relatively quickly, often leaving me in the 12.2 to 12.3V range if I don't act to charge it. I suspect that the AGM can provide more juice than the OEM flooded cell, but I have no way of knowing for sure, as I can't compare them.

That said -- I'm optimistic that the disconnect of the battery sensor (as discussed in another forum entry) will resolve my battery drain problem, or at least mostly so. If I can keep my AGM fairly well charged, using only the native recharging capability of the LC, then I think I'll be OK.

Although slightly unrelated, I ran an Optima Yellowtop in my -08 GMC 1500 and if the truck didn't run at least once a week the battery would be too low to start. There was nothing draining on it either, just couldn't hold it's own juice to save a life.

 

[EOD Guy]

I replaced my OEM battery with an Optima Yellowtop (same one as EOD_Guy) March 5th of last year (2025). I definitely haven't had any problems with it per se, but I still have a problem with my battery level dropping (what I think is) excessively and relatively quickly, often leaving me in the 12.2 to 12.3V range if I don't act to charge it. I suspect that the AGM can provide more juice than the OEM flooded cell, but I have no way of knowing for sure, as I can't compare them.

That said -- I'm optimistic that the disconnect of the battery sensor (as discussed in another forum entry) will resolve my battery drain problem, or at least mostly so. If I can keep my AGM fairly well charged, using only the native recharging capability of the LC, then I think I'll be OK.

So far - so good on my solar charger, mounted under the roof rack, keeping the LC's battery topped off. Only one "no start" since my installation and that was my fault!

 

[basicxj]

A good AGM deep cycle battery will often times rest at a higher voltage than a standard flooded lead acid battery will.

It is up to the vehicle’s charging system and your usage as to whether that AGM battery becomes fully charged and delivers that extra voltage or not. Most newer vehicles have degrees of parasitic drain on the battery- if it isn’t charged completely by the vehicle, you top it off periodically with an AGM capable battery charger if you want to see the AGM’s full service life.

How often you need to do that depends on the application, the additional equipment installed and the current resting voltage. I used to top my battery off overnight once or twice per month depending on state of discharge. Not a huge deal- park, connect charger, check/disconnect in the morning and go. It would completely charge overnight while I slept. You can even install a pigtail to plug in a charger to make that easier and quicker if your vehicle doesn’t get used regularly. Partial state of charge isn’t kind to a battery over time. Good and expensive upgraded battery? Periodic maintenance to keep it that way.

 

[Masbirdies]

I know I'm jinxing myself.. I haven't had any issues on the OEM 12v battery. Year and half of ownership and ~11K on the clock. I do have a NOCO jump box I keep charged and leave it in the LC. I don't have any Toyo app services, and I disabled the DCM. I don't have any other aftermarket kit setup on the 12v system either. My guess is all that stuff running when the LC is parked doesn't help matters.

I know folks are upset at this, but it would seem a lot of hybrid vehicles suffer from this issue. I had an older Nissan Leaf (full EV/commuter car) years ago, and the 12v battery issue was roughly the same as the LC now. I did fix that with an AGM 12v replacement.

I have been eyeballing an Optima Yellowtop swap. I may just wait until the OEM takes a poop. I know EOD guy did one? Anyone else on here swap one in with good results for the last 6-12months? TIA!

Sorry to hijack the thread, how did you disable the DCM?

 

[D-Train]

Sorry to hijack the thread, how did you disable the DCM?

Let figure out a solution for disabling the DCM telematics - Silencing Antennas

I'm hoping we can get a solution for current gen Toyota infotainment, similar to this for the previous gen: https://www.tacomaworld.com/threads/simpler-solution-for-disabling-the-dcm-telematics-silencing-antennas.821649/ Why? Well, first of all, nothing that doesn't need an internet connection...

www.landcruiserforum.com

Toyota DCM/Safety Connect Bypass Harness - Fits 2020+ Toyota Vehicles

Adapter kit for Disconnecting the Data Communication Module (DCM) on a Toyota vehicle without disabling the front right speaker or handsfree bluetooth microphone

www.autoharnesshouse.com