Deep cycle agm battery replacement?

[AlexGates]

I'm not an expert, but the computer seems to require different settings/needs for an AGM vs lead battery. Bumping around tunes, I have seen "AGM" mentioned.

Not a Land Cruiser, but my F150 uses an AGM. Apparently Ford's settings only charge the thing to 80%, people have changed that to 90% (or higher) using Forscan (I know, funny name). My non-expert take is that you can put an AGM in your LC, but because the Toyota system thinks it is a lead acid, it won't charge it to its full potential/properly. Basically, it's a waste of money.

I'll note that my tenders/chargers have a setting for "12v," "12v AGM," and "12v Lithium."

 

[Mikie]

I'm not an expert, but the computer seems to require different settings/needs for an AGM vs lead battery. Bumping around tunes, I have seen "AGM" mentioned.

Not a Land Cruiser, but my F150 uses an AGM. Apparently Ford's settings only charge the thing to 80%, people have changed that to 90% (or higher) using Forscan (I know, funny name). My non-expert take is that you can put an AGM in your LC, but because the Toyota system thinks it is a lead acid, it won't charge it to its full potential/properly. Basically, it's a waste of money.

I'll note that my tenders/chargers have a setting for "12v," "12v AGM," and "12v Lithium."

Not sure what you mean by "bumping around tunes", but I'm pretty sure that there is no option (setting) with the LC that would allow you to change the battery charging profile from "flooded lead acid" (which is what the OEM battery is) to AGM. I've looked thru Carista and OBD specs, and neither shows an option for specifying the battery profile type. I also asked my Toyota tech (who is a Master Tech) about this, and he also said that there is no way for us (or for him using GTS) to set a battery profile type.

For sure, some other makes/models have this -- I watched a video of a guy upgrading his battery from flooded cell to AGM in his car (I think it was a VW), and after making the physical battery swap, he went into the car's customization menus to change the battery profile type from Flooded Cell to AGM.

 

[WookieBait]

“Charge” and “bring to an optimal state of charge” are two different things. An AGM replacement starting battery and an AGM Deep Cycle Battery are also two different things.

If you are talking about the latter, you’ll find the voltage required to bring one to an optimal state of charge varies amongst manufacturers and battery models, and many of the higher end batteries are capable of a resting voltage at full charge that is greater than most electrical systems are capable of charging it to. To maintain optimal state of charge and reach full service life, batteries in this category benefit from being topped off regularly with an AGM compatible charger. Running a high performance AGM Deep Cycle at partial state of charge for long periods of time reduces its service life.

If you want definitive answers, ask about a specific battery- they usually have information buried in the specs that is helpful. Some time spent with a digital multimeter clipped onto the battery’s posts as you put the Land Cruiser through its paces would be revealing as well.

I was looking at the x2 agm battery SLI48AGMDP X2Power which to my understanding is the same as the Northstar / Odyssey requiring a float charge of 13.5-13.8v and a cycle service of 14.4 - 14.8v but sounds like reading here there is no agm charging profile so wouldn't really be ideal without using a secondary method like a noco to keep it topped off.

Perhaps the interstate Costco agm would be a better choice but I haven't been able to find the specs for it yet. Item Number1624799

 

[Mikie]

I'm not an expert, but the computer seems to require different settings/needs for an AGM vs lead battery. Bumping around tunes, I have seen "AGM" mentioned.

Not a Land Cruiser, but my F150 uses an AGM. Apparently Ford's settings only charge the thing to 80%, people have changed that to 90% (or higher) using Forscan (I know, funny name). My non-expert take is that you can put an AGM in your LC, but because the Toyota system thinks it is a lead acid, it won't charge it to its full potential/properly. Basically, it's a waste of money.

I'll note that my tenders/chargers have a setting for "12v," "12v AGM," and "12v Lithium."

I should mention -- even if you can't fully charge an AGM with the LC, it doesn't necessarily mean that an AGM battery upgrade is a waste of money...

First, I should note that my AGM battery (Optima DH6) has a higher capacity than the original OEM battery (so, even if it won't fully charge, it may have similar usable capacity to the OEM). And with my AGM, I've been able to drop the voltage down (while camping) to 11.8 V and still start the car without any problem. Others have reported that with the OEM battery, if it drops much below 12.2 V, the car fails to start (because the voltage plummets before the hybrid system can boot and switch on the traction battery).

Secondly, there are a whole host of advantages of an AGM over a flooded cell...
- AGM batteries are MUCH more (10-15 times) resistant to shock
- AGM batteries are more tolerant of temperature extremes
- AGM (deep cycle) batteries are more tolerant of deep discharge
- AGM batteries are spill-proof (sealed)
- AGM batteries do not need to be refilled/maintained (sealed)
- AGM batteries typically don't vent hydrogen gas
- AGM batteries typically have a longer lifespan

 

[D-mac]

I was looking at the x2 agm battery SLI48AGMDP X2Power which to my understanding is the same as the Northstar / Odyssey requiring a float charge of 13.5-13.8v and a cycle service of 14.4 - 14.8v but sounds like reading here there is no agm charging profile so wouldn't really be ideal without using a secondary method like a noco to keep it topped off

I’ve been using AGM batteries from Odyssey and Optima for over 20 years with stock charging systems on different cars, and have never had issues. Which AGM battery manufacturers require their batteries to be “topped off”? All of them do warn against overcharging batteries as unsafe... It seems like some people interpret the wider safe operating range and durability of AGM batteries as a reason to "top off".

 

[AlexGates]

Not sure what you mean by "bumping around tunes", but I'm pretty sure that there is no option (setting) with the LC that would allow you to change the battery charging profile from "flooded lead acid" (which is what the OEM battery is) to AGM. I've looked thru Carista and OBD specs, and neither shows an option for specifying the battery profile type. I also asked my Toyota tech (who is a Master Tech) about this, and he also said that there is no way for us (or for him using GTS) to set a battery profile type.

OTT lists it, though it may not apply to our LCs. Services - OTT - Overland Tailor Tuning

Otherwise, I don't know. I haven't had battery issues and I've had my LC open all day, I have to poorly thought out hatch lights too, the ones that don't turn off. I need to do EOD's mod at some point.

 

[ultane]

It's not normal for a regular (non-electrified) car with a regular (big) battery... Unfortunately, with the LC, I'm not at all surprised that his battery died while loading the car, the small battery drains VERY quickly.

And the electrical "overhead" with this car is incredible! Yesterday I charged my 12V Optima AGM battery (I had the hybrid system on for 25 min), and after that I was showing 94% charge at 12.6V (it was 60% at 12.33V before the recharge). Now, after the car sat undisturbed over night, I'm at 69% and 12.42V. If I had done anything so foolish as to open the liftgate or any of the doors, the drop would have been much greater! I think this is crazy!!!

And if your LC has the optional liftgate lights and/or the optional door sill lights, these very bright lights, which have no automatic timed turn-off, will greatly accelerate the 12V battery drain...

Incidentally, I've no idea how the LC recharges the 12V battery so quickly... My 5 amp Noco wall charger (in AGM mode) would have spent several hours accomplishing the same thing that my car (ostensibly) did in less than a half hour.

Apparently, Toyota has replaced a bunch of 12 volt batteries that were less than perfect. Maybe let them load test yours(?).

 

[Mikie]

Apparently, Toyota has replaced a bunch of 12 volt batteries that were less than perfect. Maybe let them load test yours(?).

Yep, did that... Toyota tested the new AGM battery (installed in the LC), and it tested at 85% charge and 100% health....

(BTW, I was a bit surprised that the charge was only 85%, since I had just driven 35 minutes to get to the dealer.)

 

[WookieBait]

Yep, did that... Toyota tested the new AGM battery (installed in the LC), and it tested at 85% charge and 100% health....

(BTW, I was a bit surprised that the charge was only 85%, since I had just driven 35 minutes to get to the dealer.)

85% charge with an AGM probably is about right if the LC doesn't have an AGM charging profile unfortunately.

 

[ultane]

Yep, did that... Toyota tested the new AGM battery (installed in the LC), and it tested at 85% charge and 100% health....

(BTW, I was a bit surprised that the charge was only 85%, since I had just driven 35 minutes to get to the dealer.)

I was referring to them checking the OEM battery to make sure it is not defective.

Your AGM will never test at 100% charged, on your charging system. It doesn’t charge at a high enough voltage. It only charges at the required voltage for a flooded lead acid battery.

 

[cozen_cruiser250]

That doesn’t seam normal..

You’d think so, but it definitely happened. Nothing was on except the occasional door and rear hatch opening while loading the truck over an hours time. I guess the combo of the hatch lights and door sill lights killed the battery.

 

[basicxj]

I was looking at the x2 agm battery SLI48AGMDP X2Power which to my understanding is the same as the Northstar / Odyssey requiring a float charge of 13.5-13.8v and a cycle service of 14.4 - 14.8v but sounds like reading here there is no agm charging profile so wouldn't really be ideal without using a secondary method like a noco to keep it topped off.

Perhaps the interstate Costco agm would be a better choice but I haven't been able to find the specs for it yet. Item Number1624799

I have used Optima (a Red Top years ago), and as it is an AGM starting battery rather than an AGM deep cycle my factory alternator kept it within the happy range. That old school Optima lasted almost a decade. Much like a flooded lead acid battery, a Red Top will not fully rebound if deeply discharged as it was not designed to be deep cycled.

In my last vehicle, I used a Northstar AGM deep cycle. Great battery, but it really lasts longer if not kept at a partial state of charge. I should have been more diligent topping it off rather than relying on the alternator to do its best. I eventually replaced that Northstar with an Odyssey Performance AGM deep cycle, and much like the Northstar the alternator (which would show charging voltage up to 14.7V in that vehicle) was not sufficient to fully charge the Odyssey. An overnight top up on my Noco charger would give me resting voltage above 13V, and I'd do that once every 3-4 weeks.

Mainstream branded AGM batteries will act a lot like the the OEM flooded lead acid batteries, whereas the more exotic higher performance AGM deep cycles can become stubborn about taking a complete charge if only charged by the vehicle itself. The vehicle, be it alternator or converter like in the Land Cruiser, is not the ideal way to charge a high capacity high performance AGM deep cycle.

Based on my ownership experience with the Odyssey Performance series, that is what I will probably install in the Land Cruiser when the time comes. It would start my Jeep (equipped with bonus electronics) when voltage dropped as low as 11.5V which was impressive when the original Jeep battery was a no-go at 12V even. I will rig a pigtail for the battery to make periodic overnight top up charges convenient.

If you want more battery redundancy when away from a source of charge, a high performance AGM deep cycle is worth the money with the understanding it will live longer if maintained with regular top up charges to avoid staying in "partial state of charge" territory for long periods.

 

[basicxj]

Yep, did that... Toyota tested the new AGM battery (installed in the LC), and it tested at 85% charge and 100% health....

(BTW, I was a bit surprised that the charge was only 85%, since I had just driven 35 minutes to get to the dealer.)

If you like your AGM's performance at 85% state of charge, you'll love it (and love it for longer) by giving it periodic maintenance charges to 100% capacity.

Relying on the vehicle to do all of the charging might not allow that battery to reach its full service life expectancy.

 

[EOD Guy]

You’d think so, but it definitely happened. Nothing was on except the occasional door and rear hatch opening while loading the truck over an hours time. I guess the combo of the hatch lights and door sill lights killed the battery.

Don't forget, if any circuit is energized (door sills / hatch light) the body module computer is also on, waiting for a command. If the body module is on so is the DCM, telematics and ECU all either active or awaiting a command. In my case the OEM battery wouldn't last for just a couple of hours. I replaced it with the Optima and it would last for an entire day........... very recently I discovered 3 days (approx 24 hrs total) was it's limit.

 

[D-mac]

If you like your AGM's performance at 85% state of charge, you'll love it (and love it for longer) by giving it periodic maintenance charges to 100% capacity.

Relying on the vehicle to do all of the charging might not allow that battery to reach its full service life expectancy.

My understanding was that charging to 100% reduces the lifespan of batteries, which is why OEM charging systems don't do this for the 12v batteries, or the high voltage battery array used in the hybrid system that are warrantied for 150,000 miles (at least in my state).

 

[cozen_cruiser250]

Don't forget, if any circuit is energized (door sills / hatch light) the body module computer is also on, waiting for a command. If the body module is on so is the DCM, telematics and ECU all either active or awaiting a command. In my case the OEM battery wouldn't last for just a couple of hours. I replaced it with the Optima and it would last for an entire day........... very recently I discovered 3 days (approx 24 hrs total) was it's limit.

So would you still upgrade to an optima battery without your solar panel or charging it occasionally?

 

[basicxj]

My understanding was that charging to 100% reduces the lifespan of batteries, which is why OEM charging systems don't do this for the 12v batteries, or the high voltage battery array used in the hybrid system that are warrantied for 150,000 miles (at least in my state).

Deep cycle AGM batteries are designed to be discharged and recharged multiple hundreds of times from a fully charged state. Running them in partial state of charge can diminish their ability to be recharged to that fully charged state, and relying strictly on the vehicle to recharge them has their performance become reduced over time.

Don’t confuse the traction (hybrid) battery and its charging and longevity characteristics with the 12V battery and its charging characteristics- different design, different parameters for use. Don’t confuse a 12V flooded lead acid or AGM starting battery with an AGM deep cycle either, for the same reasons. My comments only apply to the deep cycle AGM battery. Starting batteries by design are not intended to be deeply discharged (they sustain permanent damage from doing so) where deep cycle batteries are designed specifically for that purpose.

The charge routine you describe is more appropriate for Li ion type batteries like you would find in a cell phone or a Tesla for example. In the Tesla the computer juggles that state of charge across numerous individual cells to optimize battery life. If memory serves correctly, the technology used by Toyota for its traction battery is not Li ion, but Nickel Metal Hydride (which has different characteristics).

 

[EOD Guy]

So would you still upgrade to an optima battery without your solar panel or charging it occasionally?

Yes, I own several Toyotas, all of which I've replaced the OEM battery (IMO they aren't worth a damn). The solar panel keeps it topped of for day to day, no issues what so even when I don't drive it for a month or so, even with the occasional open door for a few hours of working on mods (the OEM went flat after 2 - 3 weeks without starting with zero open door occasions) It's a very recent discovery that I've determined that an extended open door period requires a trickle to maintain the 12v battery level. I chose an Optima but other brand "high end" batteries might work equally as well.

 

[Mikie]

I was referring to them checking the OEM battery to make sure it is not defective.

Your AGM will never test at 100% charged, on your charging system. It doesn’t charge at a high enough voltage. It only charges at the required voltage for a flooded lead acid battery.

I replaced my OEM battery very early on in my LC ownership, for all of the benefits provided by an AGM. SFAIK, the original battery was not defective.

I do a lot of remote area camping with my LC, and the advantages of an AGM were important to me. That said, I was (and still am) disappointed with how quickly the Optima AGM battery discharges, even for very small loads -- so that's why I wanted Toyota to test it just to make sure that it was not defective...

Given the tons and tons of research I've done since I got the LC, I'm not sure I would go with an AGM again. Would be a tough decision, I could go either way. My alternative to an AGM would be an upgraded flooded cell battery that Toyota sells (Toyota TrueStart label) that has higher capacity than the original OEM battery.

 

[wpage]

I replaced my OEM battery very early on in my LC ownership, for all of the benefits provided by an AGM. SFAIK, the original battery was not defective.

I do a lot of remote area camping with my LC, and the advantages of an AGM were important to me. That said, I was (and still am) disappointed with how quickly the Optima AGM battery discharges, even for very small loads -- so that's why I wanted Toyota to test it just to make sure that it was not defective...

Given the tons and tons of research I've done since I got the LC, I'm not sure I would go with an AGM again. Would be a tough decision, I could go either way. My alternative to an AGM would be an upgraded flooded cell battery that Toyota sells (Toyota TrueStart label) that has higher capacity than the original OEM battery.

Had good reviews on Interstate batteries.
The narrow dimensions of the LC battery carrier makes choices for "bigger or Better" concerning.