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Losing my patience with AGM batteries

Hulk

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Matt can you measure your voltage? From your ham radio perhaps? Check it before you do anything... then turn the key and check again before you hit the starter. I think normally you should see 12.2-12.4 even when the truck has been sitting for a few days, then at most a .1v drop when you fire up the idiot lights.

This is direct from the battery. I went to charge it but my Noco battery charger said it was already at 100%. If I keep getting the clicking, I may get the battery tested.

voltage-80.jpeg
 

nakman

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@Hulk sounds like you might have the typical starter contact/plunger issue, as Dave already suggested. Have you ever replaced those?
 

Hulk

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@Hulk sounds like you might have the typical starter contact/plunger issue, as Dave already suggested. Have you ever replaced those?

Yeah, I've replaced them a number of times. I finally completely replaced the starter recently. I don't think that's the problem -- it starts fine with a full battery.
 

DaveInDenver

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Was the truck outside for a while before you took that measurement? IOW is the battery pretty cold? When did you last fully charge it?

A value of 12.54V can't remotely be called 'charged' but would represent between about 60% and 80% charged. In winter that being on the upper end. Batteries being chemical reactions are temperature sensitive. So 80% at 25°C would be 12.7V but at 5°F the same battery would read maybe, I dunno, something like 12.65V just due to the lower temperature slowing the reaction. Its actual capacity would be more obvious, that being how much current it can source but that's not as easy a measurement to make so we're left to infer with voltage.

voltage-band2.jpg


leadacidcapacityvstemp_mid.jpg


So none of this (resting 12.54V) wouldn't necessarily indicate a bad battery. You'd have to do a couple of additional tests. The main one you can do at this point would be read voltage while cranking. As long as it stays above 9.6V it would be called good. Higher than 9.6V is better of course but unless you grossly oversize the battery you have to expect it to dip at least a little. I'd personally want to see mid 10V in any weather unless it's subzero.

It's possible for cranking voltage to dip below 9.6V on a battery that's fine. It could just indicate it's not sized right. A battery that's too small or just too small in the cold could be fine in a car with a less taxing starter. But that's not really the case here since you're using a battery that's correct for the truck so only condition (or secondary issue with the starting system) is important.
 
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bassguyry

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Well, damn. I guess my AGM isn't fully charged either, because I typically see 12.4-12.6V on the battery (during cold weather, at least). Maybe I'll just buy a damn AGM battery charger and be done with it.

If this keeps up, I'm going back to flooded lead acid batteries. #annoyed
 

DaveInDenver

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Well, damn. I guess my AGM isn't fully charged either, because I typically see 12.4-12.6V on the battery (during cold weather, at least). Maybe I'll just buy a damn AGM battery charger and be done with it.

If this keeps up, I'm going back to flooded lead acid batteries. #annoyed
LOL. Yeah, AGM are temperamental so unless you put the work in for care and feeding them it's not worth the money.

For reference, 12.94V at 46.6°F is what I'm reading today on a pair of 3 year old Odyssey PC1500 batteries after resting 24 hours from the most recent charge.

I run an Iota DLS-45 with an IQ4-AGM controller module on them once a month (usually the first of the month) over the winter. This puts 8 hours bulk-absorption of 14.7V at up to 45 amps (this is 0.35C for my ~130 A-hr pair) and then floats at 13.6V, which I let go at least 16 hours.

I also have a solar panel and Morningstar SS-MPPT-15L that has a temperature compensated profile that I let sit on them but in the winter the sun doesn't sit on the truck long enough being in shade by noon to get 14.7V or higher very long and the temperature might vary from 15°F to 40°F over that time.

Ideally at colder temperatures I want to be higher (technically at 0°C/32°F Odysseys will tolerate as much as 15.3V, they follow a compensation of +/-24mV/°C with 14.7V at 25°C as baseline) but I figure 8 hours of consistent 14.7V is better.

IMG_0697_mid.jpg
 
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bassguyry

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Alright, now I'm super annoyed. I tried to find a manual or decent spec sheet on my X2 Power AGM, in order to find the 100% charge voltage, but only found this. That said, according to this part of the manual, the 100% charge voltage should read above 12.6V:

Screen Shot 2020-12-04 at 2.41.50 PM.png

Maybe this is truly only 80% charged at 12.6V? What gives?! :banghead:

I should've stayed in EE instead of switching to finance. Math is hard.
 

RayRay27

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I kinda got fed up with expensive AGM's also. I have switched back to regular flooded lead acid batteries. :dunno:
Are you seeing better results with flooded batteries? My thought is just to go back to a flooded battery. I don't think 80's like AGM's, just my 2 cents.
 

rover67

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I've had the setup in the 80 for less than a year now, so not real data... :/ Also haven't tortured it all like I like to to be able to say one way or the other. I was going through AGM's every 3-4 years with the 60 which had a pretty high charge voltage (peak was like 14.7). That being said I did nothing, and I mean nothing to maintain them outside of sticking a cheap charger on them when I killed them from stupidity on occasion. My first optima did last 11 or 12 years tho. That's what started my love affair with them. I literally tripped while running it down to the street (drunk) and tossed it like 10' onto concrete. Had a big dent on the bottom corner from that. It worked another 7 years after that? After that battery I had bad luck with all the rest. They just slowly lost capacity on me. Even the really nice diehard gold platinoooo or whatever one all the bro's and ladies loved on all the forums. Had one in Al's Jetta, the 40, and the 60 for a while. All kinda just started to suck. The Jetta's battery almost left us stranded in S Dakota one crisp snowy winter night after stopping to get diesel.. That pissed me right the f off... it was only like 3 years old. Anyhow went back to optima, same.

It's probably how I am taking care (or was taking care) of them honestly. Also fair to mention I did dumb crap like welded with the 60's batteries more than a few times. Anyhow since switching to flooded lead acid in the Jetta and 40 I rarely think about batteries. The 60 also got a flooded lead acid for the second battery right before I sold it. After saying this I'll have all my batteries die tomorrow.

Anyhow, logic was a decent group 31 flooded deep cycle battery is a shade over 100 bucks. That's a much easier pill to swallow.. and I can be mean to them... well, meaner and don't get pissed when they lose capacity or flat out die.

The tractor's battery is a lead acid one from friggin walmart that's 14 years old and it literally sits outside for weeks in between starts. I have run it flat a few times leaving gauge lights on.... even in sub zero temps it manages to start the ol' girl still. The motorcycle batteries... well that's another story.. those little SLA batts seem to seriously suck. I switched to Shorai (Lithium Iron) and they are like amazeballs for that application.

*steps off soap box*
 

DaveInDenver

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Alright, now I'm super annoyed. I tried to find a manual or decent spec sheet on my X2 Power AGM, in order to find the 100% charge voltage, but only found this. That said, according to this part of the manual, the 100% charge voltage should read above 12.6V:

View attachment 91033
Maybe this is truly only 80% charged at 12.6V? What gives?! :banghead:

I should've stayed in EE instead of switching to finance. Math is hard.
Those X2 batteries are made by NorthStar (which is owned by EnerSys same as Odyssey and is the main competitor to Johnson Controls/Optima). They make a quality product so don't get too overly wrapped around the axle. Just know that in my experience EnerSys AGM batteries are just more finicky.


Anywho, 12.6V is IMO hard to call good or bad, it's kind of the meh, I dunno number. If a battery was brand new, temperature was a perfect 77°F and the battery had just sit for a day after a charge and measured 12.6V that would unquestionably indicate bad.

BTW the rest is important. You need to let a newly charged battery sit for about a day to let what's called the surface charge to dissipate to get an accurate measurement. It would require even more esoteric discussion than I've already dumped but suffice to say voltage isn't the best indicator for condition, state or charging. It's just one number out of context.

OTOH a few year old battery that's not been handled with white gloves just randomly measuring 12.6V is actually typical and doesn't tell you anything definitely. I wouldn't replace it anyway. Batteries age and won't measure an ideal 13.0V open circuit forever no matter how good you treat them.

In any case knowing what the battery voltage drops to while cranking (or alternatively with the fridge or radio on, basically under load) is the more important number. Comparing a battery OCV of 13.0V that drops to 10.0V cranking to another that sits OCV of 12.6V but only drops to 10.5V cranking the second is in better shape and just needed a charge.

Just my $0.02 but I'd get a good charger on it and see what happens. I think getting batteries on a quality shore charger regularly is the most important thing you can do. All the voltage bumping on alternators isn't going to substitute for that and comes with some risk of damaging the charging system or battery.

In fact I usually hesitate to really recommend tinkering with them unless you're willing to monitor your electrical system. Vehicle charging systems are never ideal and really only there to prevent from going flat. They can't fully charge and they do nothing about conditioning.
 
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ScaldedDog

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My experience with AGM's (DieHard Platinums) sure is different than that of most in this thread. The two huge Group 65 ones in my Excursion will be nine years old in January. The truck sits a lot ( only 50K in those nine years), and they have discharged to the point of not starting the truck countless times. I do have an Odyssey charger, but don't bother to charge the batteries one at a time. I just hook it up and let it sit for a few hours or a few days, several times a year. They generally sit for long periods of time between 12.1 and 12.4v. The only way they've been treated well is that the truck never sits outside anywhere but Moab, and the garage is heated. I've thought about replacing them proactively, but they just won't die, so I keep using them. PSD's are notorious for bad behavior with bad batteries, as I witnessed every three years when I ran Interstate lead acid ones. When that starts, I won't hesitate to buy AGMs again.

I did have a smaller version of the same battery go bad in the 4Runner, but that thing only sees 100 miles in a good year, and can sit for weeks before I remember to throw the charger on it. The replacement is probably six years old, so I'm still ahead if it died today.

Mark
 

bassguyry

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Thanks, @DaveInDenver - that's really helpful info. I'm going to test my cranking voltage just to confirm that the battery is still in decent shape. I just bought it in March, but obviously haven't done any sort of conditioning or charging outside of just running the truck, which had a couple of bum alternators in a row.

I also pulled the trigger on a NOCO Genius 5 AGM charger, so I'll start using that to charge and condition the battery periodically. I paid $300 for the damn battery, so I'll do what I need in order to keep it around long-term.
 

DaveInDenver

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I also pulled the trigger on a NOCO Genius 5 AGM charger, so I'll start using that to charge and condition the battery periodically. I paid $300 for the damn battery, so I'll do what I need in order to keep it around long-term.
No matter if you spend $300 or $50 for a battery putting it on a charger regularly is going to help it last longer. There's no downside to it.
 

bassguyry

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Charged up the battery this morning, and let it “condition” for a bit (whatever that means). Charged voltage is about 12.55V. Also measured to voltage while cranking, and it only dropped to about 11.7V, so that’s good. I guess I’ll just throw the charger on it once a week or so, which isn’t a huge deal, especially if it results in longer life.
 

Lefty

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@bassguyry, I’ve been hit with the same problem. Have you had any starting issues during this cold snap since you’ve been using the noco?
 

RayRay27

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I replaced my original alternator last week and I am seeing higher voltage already but I am still going to continue to put my battery on the float charger if it sits more then a week.
 

SteveH

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I have a plow truck, a tractor, FJ40, FJ62, and a 7.3 Powerstroke Ford - all with flooded batteries and all are plugged in 24x7 on maintenance chargers. I average about 7 years life on batteries, and typically buy Interstate blems (although they are now $75, so I'm no longer buying them or Walmart/Sam's club stuff). I'm a battery cheapskate.

My plow truck has been plugged in for 25 years and has just had a handful of batteries. I'm absolutely convinced that maintenance chargers (either the $4.99 Harbor Freight ones, or better ones) are all it takes to greatly increase the life of these batteries. My tractor battery is from 2009, my FJ40 battery from 2014. and my FJ62 battery from 2013 just died this past year. I had a sealed Toyota True Start last 10 years. After bad experiences with Optimas not holding a charge for 2 weeks, I have just gone back to flooded batteries, with all their drawbacks of oozing acid, terminal cleaning, etc.

I would buy a sealed battery if I could be sure it would last 8 years or so without issue.
 

bassguyry

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@bassguyry, I’ve been hit with the same problem. Have you had any starting issues during this cold snap since you’ve been using the noco?
Not one issue, actually. It always takes a second longer to start up when it's super cold (less than 20 degrees, typically), but it's definitely much better since I've started using the NOCO.

I actually managed to drain the battery down to about 7.5 volts a few weeks ago, after I left my WeBoost cell booster plugged in for a few days straight. The NOCO did a great job charging it up (took about 20 hours), and it's good as new.
 

Lefty

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That’s good to hear. I’m going to pick up one. Did you get the onboard version (genius5x2) or the genius5?
 
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