Deep cycle agm battery replacement?

[Mikie]

For those of you that understand this stuff better than me, does the following sound reasonable?

The original OEM flooded cell battery had a CCA of 600, and the Optimal Yellowtop DH6 has a CCA of 800. I haven't done a lot of testing yet, but at first glance it appears that for whatever reason(s) the Optima only gets up to a little over 80% SOC from running the LC's hybrid system (driving or not). Since 82% of 800 is ~650, would it be reasonable to figure that the Optima (at 82% SOC) will offer about the same (or slightly more) usable power as the OEM battery (at 100% SOC)? I know that we aren't cranking the engine, so I don't know if the CCA comparison is valid.

If the above is reasonably close to being true, then it would make sense to keep the Optima over the OEM, as the usable power will be similar, but the Optima provides all of the important benefits of an AGM battery.

If I wanted to stay with flooded cell batteries (that can fully charge from the car), an option is a Toyota TrueStart battery upgrade, which offers 770 CCA. I'm pretty sure that their Group H6-LN3 (Part Number 00544-H6074-770) is a direct flooded cell replacement, tho I haven't confirmed this with Toyota.

For whatever reason, I cannot find any aftermarket web sites that list replacement batteries for the '24 or '25 Land Cruiser.

 

[Bad1975]

For those of you that understand this stuff better than me, does the following sound reasonable?

The original OEM flooded cell battery had a CCA of 600, and the Optimal Yellowtop DH6 has a CCA of 800. I haven't done a lot of testing yet, but at first glance it appears that for whatever reason(s) the Optima only gets up to a little over 80% SOC from running the LC's hybrid system (driving or not). Since 82% of 800 is ~650, would it be reasonable to figure that the Optima (at 82% SOC) will offer about the same (or slightly more) usable power as the OEM battery (at 100% SOC)? I know that we aren't cranking the engine, so I don't know if the CCA comparison is valid.

If the above is reasonably close to being true, then it would make sense to keep the Optima over the OEM, as the usable power will be similar, but the Optima provides all of the important benefits of an AGM battery.

If I wanted to stay with flooded cell batteries (that can fully charge from the car), an option is a Toyota TrueStart battery upgrade, which offers 770 CCA. I'm pretty sure that their Group H6-LN3 (Part Number 00544-H6074-770) is a direct flooded cell replacement, tho I haven't confirmed this with Toyota. For whatever reason, I cannot find any web sites that list replacement batteries for the '24 or '25 Land Cruiser.

What’s the. voltage at that SOC? Amperage is irrelevant if the voltage isn’t enough to start the electronics. In my experience around 12.3VDC and under results in 11.7VDC or lower when attempting to start which the 250 won’t operate off of.

I’m wondering if the voltage monitor circuit on the negative post may be a source of draw and also if you could start the vehicle in a no start condition if temporarily disconnected.

As EOD stated the battery draws down at an alarming rate from just doors open, likely due to the amount of ECUs utilizing the CANBUS when woken up from a door unlock and a left open event.

I’ve had three separate no start conditions from performing work on the vehicle for about 2 hours with a door open or just multiple entries and exits over a day while working on it with the hood open.

Ordered a NOCO boost yesterday after watching Dissent off-road at MOAB kill the battery with a tip event that disabled Hybrid and ICE start (engine shut down) and needing to perform a simple winch pull to get the vehicle started. Once they pulled it back straight the battery was low enough that it wouldn’t start and required a jump.

 

[Mikie]

I have done quite a bit of monitoring of my 12V battery voltage, and in general, without external recharging of the 12V, and with almost exclusively short trips (~10-15 min), I manage to keep the battery voltage over 12.4 volts. But oftentimes, just barely. And this is with minimal battery power usage -- which will change big time once I start my summer/fall camping trips.

This is the voltage reading after the car "recovers" after a discharge. Even opening and closing a door may drop the voltage a couple decimal points, but then in a half our or so it recovers back up to the original voltage.

BTW -- I am so convinced that using a jump starter will become a "regular use" kind of thing when I'm on a week long camping trip, I actually carry TWO Noco GB40's... One for everyday use, and the other is a real back-up (important, since oftentimes I'm camping waaaay out in the boonies!)

 

[AlexGates]

I have done quite a bit of monitoring of my 12V battery voltage, and in general, without external recharging of the 12V, and with almost exclusively short trips (~10-15 min), I manage to keep the battery voltage over 12.4 volts. But oftentimes, just barely. And this is with minimal battery power usage -- which will change big time once I start my summer/fall camping trips.

This is the voltage reading after the car "recovers" after a discharge. Even opening and closing a door may drop the voltage a couple decimal points, but then in a half our or so it recovers back up to the original voltage.

BTW -- I am so convinced that using a jump starter will become a "regular use" kind of thing when I'm on a week long camping trip, I actually carry TWO Noco GB40's... One for everyday use, and the other is a real back-up (important, since oftentimes I'm camping waaaay out in the boonies!)

These things are Chinese weird name jump boxes, you are probably on to something, especially in your circumstance.

I killed a Gooloo after just one jump of a completely dead battery. Read 70% remaining, but when I went to recharge the screen went blank and the unit was toast. I still carry jumper cables, though with today’s electronics, I won’t use them to jump others.

While I haven’t had issues. I think I’ll get a lower amp Noco Genius and pig tail it for the LC. Use the 10 Amp on my pickup.

 

[basicxj]

The beautiful thing about AGM deep cycle batteries is that when discharged to or below 10V, they do not sustain permanent damage like a flooded lead acid battery does. Every deep discharge of a traditional flooded lead acid battery shortens its lifespan in the big picture.

While not all AGM batteries are deep cycle (an example is the Optima Red Top, which was made to primarily be a starting battery and not intended to be discharged below 10V), an AGM deep cycle for applications likely see discharges regularly will have a better chance at performing long term without incurring damage.

I am new to the Land Cruiser platform. I'll monitor the OEM battery and see how it holds up, but when the original battery requires replacement I'll probably be looking at an Odyssey AGM deep cycle based on previous experience provided they have a drop-in model with better specs. My Northstar AGM had some peculiarities in that it almost demanded deep discharges in order to take a full charge, whereas my last Odyssey behaved more like a standard battery and always bounced back to 13V once topped off. With the added CCA and reserve it would also give me a proper start even when discharged towards 11V as if it was no big deal. Neither AGMs were on the affordable side, but Northstar is no longer sold as a stand-alone brand due to some structural changes in the company. I used Optimas back in the day and got a solid decade out of the last Red Top I purchased (on sale at Costco), but I don't know if that kind of life is still possible from them.

 

[Mikie]

These things are Chinese weird name jump boxes, you are probably on to something, especially in your circumstance.

I killed a Gooloo after just one jump of a completely dead battery. Read 70% remaining, but when I went to recharge the screen went blank and the unit was toast. I still carry jumper cables, though with today’s electronics, I won’t use them to jump others.

The owner's manual agrees with you (WRT jumping other cars from our car)...

 

[AlexGates]

The owner's manual agrees with you (WRT jumping other cars from our car)...
View attachment 39879

That goes for any modern vehicle in my opinion, just too many electronics going on these days. I know the local patrol vehicles are not to use jumper cables, it is policy and has been for some time.

 

[Mikie]

Re the voltage required for charging an AGM battery, I have not (yet) received a response from my question to Optima, but I did find some relevant info on the Odyssey web site...

• They recommend recharging the battery before it drops to 12.2 volts, which they say is 50% SOC
• They say that for engine starting applications (not what we need for the LC), you should charge at 14.2-14.5 volts, but for cyclic applications (all of the electronics) they say you should use 14.4-14.8 volts

The LC charges initially at 14.4 volts, but drops pretty quickly to about 14.27 volts (after a few minutes). I assume that it remains at 14.27-14.28 volts until it enters float (but don't know this for sure).

 

[Quest4vertical]

What’s the. voltage at that SOC? Amperage is irrelevant if the voltage isn’t enough to start the electronics. In my experience around 12.3VDC and under results in 11.7VDC or lower when attempting to start which the 250 won’t operate off of.

I’m wondering if the voltage monitor circuit on the negative post may be a source of draw and also if you could start the vehicle in a no start condition if temporarily disconnected.

As EOD stated the battery draws down at an alarming rate from just doors open, likely due to the amount of ECUs utilizing the CANBUS when woken up from a door unlock and a left open event.

I’ve had three separate no start conditions from performing work on the vehicle for about 2 hours with a door open or just multiple entries and exits over a day while working on it with the hood open.

Ordered a NOCO boost yesterday after watching Dissent off-road at MOAB kill the battery with a tip event that disabled Hybrid and ICE start (engine shut down) and needing to perform a simple winch pull to get the vehicle started. Once they pulled it back straight the battery was low enough that it wouldn’t start and required a jump.

What size NOCO did you pick up?

 

[Bad1975]

I got the 150 to have the most power available in case of extended or repeated winching.

Came to this decision after watching the dissent video from Moab where he gently laid the 250 on its side preventing the system from being started up and killed the start battery during the recovery.

FYI the hybrid battery will charge the start battery or use power to power the 12V system when winching if the system is turned on. I did this and it supported one full length (90ft) recovery on 15% grade with light brake pressure. Hybrid battery used about 3 bars during that winch event and the 12V remained constant probably could get two pulls like this with similar conditions until the 12V would get drawn down. ICE was running for the entire pull but it drained the hybrid, so looks like even with ICE running the system need supplemental power to support winching without drawing down the 12V battery.

Plan for the future is to hook up the NOCO during any heavy winching until it’s at 50% then use it for recovery of the 12V after that if needed.