Group 27F to H6 AGM Battery Replacement (1 Viewer)

[Hroon]

2018 LC200
The battery started giving me issue so I replaced it
With interstate H6 AGM battery.

Everything fits except the battery is 1” shorter. Is this going to cause me issues? Anyone do it better?

Metal clamp goes doesn’t hold the battery properly. I had to shim it but the only think I could think off that would fit would be Lego’s.

 

[Sandroad]

Yes, it will cause issues. Your lego train is going to derail and crash.

But seriously, I wonder if the top raised area of the battery case is made for that clamping stress?

 

[jwmNC]

I don't have a suggestion on the shim, but there are several threads on here about AGM batteries and their need for higher charging voltage than the alternator provides. I had an AGM for a while, but it failed earlier than I expected so I went back to a standard OEM-type battery. There are some aftermarket battery trays that might eliminate the need for a shim, I think Slee has one.

 

[bloc]

Agreed. They arguably upsold OP to a worse battery than standard Lead Acid.

 

[UPR LC]

search the internet for "battery height adapter" or "car battery spacer". They are plastic and go below the battery to raise it.

Otherwise you could 3D print a top spacer. A lower battery would be nice, more clearance for the lugs and lower place weight.

 

[AcmeSys]

AGMs generally want slightly different voltages due to their lower internal resistance to prevent off gassing over the PRV (AGM full charge voltage is slightly higher than SLA and they can take a higher amp charge so if you throw 17v at it, it will rock and roll...)

Are there "better ways" to charge an AGM? Sure. The alternator/reg set point is slightly higher voltage for SLA and there are idealized temp curves that AGM likes but it will be fine on a stock alternator/regulator that runs around 14.8VDC (AGMs really need to be under 15 VDC - so dont toss your grandfather's old buz box shumacher battery boiler on it).

The OEM system isn't a "great" charger for SLA it just crams coulombs into the battery without a shunt for control. There are tons of AGMs in SLA automotive systems without issues. You won't get the full benifits or possible life span but in reality automotive batteries never do unless you live in Seattle and have benign temps. The up side is you don't have corrosion issues like SLA's do when they puke. I personnaly prefer AGM batteries in my own rigs if it is an option with the mounting location.

 

[KLF]

A scrap piece of PT 5/4x6 decking works perfect as a 1" spacer under a battery.

I'm on year 8 with the group 31 Odyssey AGM in my truck. Year 7 on the group 24 accessory AGM. So I reject that AGM batteries don't last long.

 

[TeCKis300]

AGMs are great batteries. But bad for starting application in the 200-series.

Have to think about the vehicle as a system.

The vehicle was designed around a standard flooded lead acid and all its thermal and charge profile characteristics. AGMs are used by OEMs too, but when they integrate them, they are packaged into thermally separated partitions away from high heat areas and tailor their regulators to match required charging profiles.

Slapping an AGM does not only prematurely wear the expensive battery, it may also add wear and tear to the vehicles electrical system. A deeply discharged battery becomes a load to the charging system. A low internal resistance / fast charging AGM can be a heavy extended load. Combine that with extra overlanding loads, and it may just prematurely wear the alternator.

It says something about compatibility when needing to plug in batteries to an external charger constantly.

 

[hoser]

I like the H6 battery size because it's a popular size for German vehicles. You can find H6 batteries made in Germany in the US (Bosch, Varta, etc). I prefer batteries made in Germany over batteries made in Mexico... but that's just me.

 

[Boston Mangler]

I'm on year 8 with the group 31 Odyssey AGM in my truck. Year 7 on the group 24 accessory AGM. So I reject that AGM batteries don't last long.

Im with you on this one sir. Day i got my Tundra i put a Group 31 Odyssey AGM in it, that i previously had in my 100 for a couple years

When i sold my Tundra 5 years and 100k later, the Odyssey was still running as strong as day 1.

I would guess 7-ish years old and lots of abuse

 

[gasman4u]

Im with you on this one sir. Day i got my Tundra i put a Group 31 Odyssey AGM in it, that i previously had in my 100 for a couple years

When i sold my Tundra 5 years and 100k later, the Odyssey was still running as strong as day 1.

I would guess 7-ish years old and lots of abuse

I was going to reply to @KLF and say that his batteries are doing VERY well and likely due to not being exposed to long seasons of hot weather being in NH.

@Boston Mangler long experience with an AGM in a much hotter climate says that's not always the case. I have yet to get more than 4 years from any of my batteries used in our cars (SLA/AGM). I'm only 3 degrees higher in latitude that you, but get lots of hot days mixed with (sometimes) very low winter temps too. I'm at a loss other than having cars that are seemingly "hard" on batteries. I won't do it with a car I don't daily, but I empirically change the other batteries at the 3 year mark (due to past experience) because I don't want to have to deal with it when I'm NOT at home.

 

[AcmeSys]

AGMs are great batteries. But bad for starting application in the 200-series.

Have to think about the vehicle as a system.

The vehicle was designed around a standard flooded lead acid and all its thermal and charge profile characteristics. AGMs are used by OEMs too, but when they integrate them, they are packaged into thermally separated partitions away from high heat areas and tailor their regulators to match required charging profiles.

Slapping an AGM does not only prematurely wear the expensive battery, it may also add wear and tear to the vehicles electrical system. A deeply discharged battery becomes a load to the charging system. A low internal resistance / fast charging AGM can be a heavy extended load. Combine that with extra overlanding loads, and it may just prematurely wear the alternator.

It says something about compatibility when needing to plug in batteries to an external charger constantly.

Sorry, but I'll swing at this one. How are they bad in the starting application?

The Toyotas are not a multistage golden calf charging system like you'd find in a closed loop DC/DC charger so implying they have any "charge profile" beyond a basic temp curve is disingenuous and the temp comp is the probably the normal 30mV/degC for FLA (AGM is something around 24mV/degC dV/dT). Where it gets the temperature measurement is unknown but the battery is not instrumented so it is a derived measurement from alternator regulator temperature and probably deviates from reality in cold weather where the regulator warms faster than the battery does. Outside of the temp comp control it is a constant voltage field controller with no shunt so it has no idea of the battery status of state of charge (no float reduction, just hammer it at bulk charge voltage with whatever the cells will eat)

I agree that on paper the underhood temps reduce service life but in my experience running AGM underhood I have not seen it be less than the normal LA battery life in hot climates. I get 3 or maybe 4 years out of the batteries no matter their flavor (and FLAs I don't top off the electrolyte so they get equal abuse from off gassing and low fluid). lead acid is a 600 cycle chemistry so it is a race condition between cycles and thermal degradation. Anything above 95F starts causing unrecoverable cannibalistic SO4 redox chemistry in FLA and AGM. AGM does charge better below freezing than FLA and in pretty much all conditions charge faster than FLA (assuming the 130A? alternator can drive the load - I don't see the charge voltage falling off so it is carrying the load).

The internal resistance is lower on AGM so not grossly low resistance like a dead short that will make an alternator cry (this is hard to quantify without having two batteries of nearly equal capacity, side by side with known charge levels and temperatures). The charge time factors reflect the loading differences (the chemistry is the same so you are looking at the glass mat factor vs resistance of ~1mm? of acid plus the same Pb and PbO2 plates and how much power you can pull in).

I didn't find good data sheets from interstate and the H6 so I used the Rolls manual to compare their AGM to FLA charge voltages in the attached.

Long story short- the AGM will be fine for a rig - Draw it way down and you'll hammer your alternator diodes and regulator when you fire up your rig. Similarly you'll also hammer them if you draw down and flatten a stock FLA/SLA battery or if you hang a 50A DC/DC charger and AUX batt in addition to the OEM circuits, 19 iPad chargers, starlink, 900W HF radio for calling in the Dominos order in Ulaanbaatar from British Columbia, and the required overland margarita mixer. Yeah, the alternator temp curve could be "better" but it is fine (cats and dogs won't be sleeping together because you install an AGM). The highest voltage I've seen on a 5.7 tundra or 200 is 14.8V. You don't need to use an external charger to float the battery constantly as a starting battery application. Sure if I was using it in an offgrid primary power application I'd care about every coulomb of possible capacity and extended life but in 99.9% of automotive applications the battery draw down during normal use is maybe 15% at start up then covered by alternator for the short charging duration. You may be the outlier but if your power system is high demand you have shunts installed and closed loop charge controllers to monitor SOC.

In the spirit of experimentation vs opinion I'll run out and get the post start charging amperage and voltage on my rig. She's been in a 13 deg F snow drift for almost two weeks so the battery should be low'ish and should see near peak alternator output for a short period.

How cold was it? The hood was frozen shut and I pried it open with an ice scraper...
Pre start battery at 12.4v and -0.2A draw from just doors open and ECUs coming on after opening the door
EFI and fuel pump priming 12.06V and -4.7A
Start up and running after 30 seconds 14.21V and 14.5A (the 200w held steady at idle and with a 2000 rpm throttle bump)
Volt/Amp steady for one minute then I turned it off because it was freezing outside. Measurements made with Flukes I trust and have cal'd. Not sure what the temp curve is for this regulator but that is a low'ish output voltage for sub freezing by any interpretation of temp comping FLA.

 

[OregonLC]

TLDR.

The Lead Acid works great as a starting battery. It works with the OEM charging system and would be a battery that I'd take around the world.

AGM's never fully charge without a DCDC. You pay more for labeled capacity but don't have any real-world gain. There is no advantage. People want the best in their truck and often go the AGM route, striving for a superior product yet there is no appreciable gain in service.

And with the price-point, capacity, and weight savings of Li, there's no reason to have an AGM as a house battery unless you're running it under the hood (with a DCDC) and need thermal flexibility greater than what an Li can offer. AGM was a bridge technology that is now obsolete, IMO.

 

[TeCKis300]

Sorry, but I'll swing at this one. How are they bad in the starting application?

The Toyotas are not a multistage golden calf charging system like you'd find in a closed loop DC/DC charger so implying they have any "charge profile" beyond a basic temp curve is disingenuous and the temp comp is the probably the normal 30mV/degC for FLA (AGM is something around 24mV/degC dV/dT). Where it gets the temperature measurement is unknown but the battery is not instrumented so it is a derived measurement from alternator regulator temperature and probably deviates from reality in cold weather where the regulator warms faster than the battery does. Outside of the temp comp control it is a constant voltage field controller with no shunt so it has no idea of the battery status of state of charge (no float reduction, just hammer it at bulk charge voltage with whatever the cells will eat)

I agree that on paper the underhood temps reduce service life but in my experience running AGM underhood I have not seen it be less than the normal LA battery life in hot climates. I get 3 or maybe 4 years out of the batteries no matter their flavor (and FLAs I don't top off the electrolyte so they get equal abuse from off gassing and low fluid). lead acid is a 600 cycle chemistry so it is a race condition between cycles and thermal degradation. Anything above 95F starts causing unrecoverable cannibalistic SO4 redox chemistry in FLA and AGM. AGM does charge better below freezing than FLA and in pretty much all conditions charge faster than FLA (assuming the 130A? alternator can drive the load - I don't see the charge voltage falling off so it is carrying the load).

The internal resistance is lower on AGM so not grossly low resistance like a dead short that will make an alternator cry (this is hard to quantify without having two batteries of nearly equal capacity, side by side with known charge levels and temperatures). The charge time factors reflect the loading differences (the chemistry is the same so you are looking at the glass mat factor vs resistance of ~1mm? of acid plus the same Pb and PbO2 plates and how much power you can pull in).

I didn't find good data sheets from interstate and the H6 so I used the Rolls manual to compare their AGM to FLA charge voltages in the attached.

Long story short- the AGM will be fine for a rig - Draw it way down and you'll hammer your alternator diodes and regulator when you fire up your rig. Similarly you'll also hammer them if you draw down and flatten a stock FLA/SLA battery or if you hang a 50A DC/DC charger and AUX batt in addition to the OEM circuits, 19 iPad chargers, starlink, 900W HF radio for calling in the Dominos order in Ulaanbaatar from British Columbia, and the required overland margarita mixer. Yeah, the alternator temp curve could be "better" but it is fine (cats and dogs won't be sleeping together because you install an AGM). The highest voltage I've seen on a 5.7 tundra or 200 is 14.8V. You don't need to use an external charger to float the battery constantly as a starting battery application. Sure if I was using it in an offgrid primary power application I'd care about every coulomb of possible capacity and extended life but in 99.9% of automotive applications the battery draw down during normal use is maybe 15% at start up then covered by alternator for the short charging duration. You may be the outlier but if your power system is high demand you have shunts installed and closed loop charge controllers to monitor SOC.

In the spirit of experimentation vs opinion I'll run out and get the post start charging amperage and voltage on my rig. She's been in a 13 deg F snow drift for almost two weeks so the battery should be low'ish and should see near peak alternator output for a short period.

How cold was it? The hood was frozen shut and I pried it open with an ice scraper...
Pre start battery at 12.4v and -0.2A draw from just doors open and ECUs coming on after opening the door
EFI and fuel pump priming 12.06V and -4.7A
Start up and running after 30 seconds 14.21V and 14.5A (the 200w held steady at idle and with a 2000 rpm throttle bump)
Volt/Amp steady for one minute then I turned it off because it was freezing outside. Measurements made with Flukes I trust and have cal'd. Not sure what the temp curve is for this regulator but that is a low'ish output voltage for sub freezing by any interpretation of temp comping FLA.

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Badly worded on my part.

I'll keep this simple. AGM batteries are great. They're also great starting batteries. They are just bad for 200-series application because components are only as good as the integration.

I've killed 3x AGM batteries in my time. Putting them on an external charger regularly is a bandaid for poor integration. Systemic undercharging leads to sulfation. Add a diode to up the voltage and you're dealing with the other end heat sensitivity of an SLA.

FLAs work great as Toyota designed. Better is the enemy of good enough, but in this application, I personally don't see how AGMs are any better.

 

[OregonLC]

I've killed 3x AGM batteries in my time.

Same here. Back in the early 2010's I was warrantying DieHard Platinum every year thinking they were junk. In reality, it was my misapplication that was junk.

 

[AcmeSys]

Presented industry data and measured the "Toyota designed" fully "system enginerded" worlds best, pope approved then optimized by the seventh sigma kanban dweeb team, charging system and showed it is lower voltage than it probably should be and am having a "enemy of good enough" pedantic debate with internet wizards? Unsurprising, but god I love the internet for the entertainment value.

If nothing else, no one can debate AGM being the better battery type for rough/high vibration environments (or is that on the table?)

Tossing Li in the mix, while good for some applications, is a whole nother can of worms for sales and marketeering pseudoscience wonk that I am not touching in here (cough...Li performance in cold conditions? ).

 

[OregonLC]

If nothing else, no one can debate AGM being the better battery type for rough/high vibration environments (or is that on the table?)

It would be on the table if it ever presented itself as an issue. The majority of vehicles here are 'touring' class overlanders. Some are faux crawlers. None see Baja 1000 abuse. Use the TrueStart in all three of our Cruisers sans issue.

 

[prharper]

A scrap piece of PT 5/4x6 decking works perfect as a 1" spacer under a battery.

I'm on year 8 with the group 31 Odyssey AGM in my truck. Year 7 on the group 24 accessory AGM. So I reject that AGM batteries don't last long

Yep, you also top them off on a regular basis which is smart with the AGM's.

 

[TeCKis300]

If nothing else, no one can debate AGM being the better battery type for rough/high vibration environments (or is that on the table?)

With 6000lb+ of inertial mass damping the sharpest forces, probably not a factor with any quality battery.

 

[AcmeSys]

that's not really how that works... but I think we are already beyond the shallow waters of people's attention spans (f=ma is just the HS version and k is just as or more important than m in modal work). batteries love low freq noise. they are lead sheet pendulums.