Sulfated Lifeline Concorde AGM Batteries

keyturbocars

Last year, I picked up a set of 16 Lifeline Concorde GPL-31T 105A/H batteries. Set them up in a 48V battery bank for my wind turbine. The batteries were brand new and in their factory boxes, but they sat in a warehouse for a long time. Got them for 1/4 regular price, so I took a chance. If memory serves me right, they were all around 40% SOC when I unpacked them from the factory boxes! NOT GOOD! They obviously sat for a long time and I knew they would be sulfated.

Up until today, I've been trying to work with all 16 batteries wired together in my battery bank, and I don't think I've had enough "horsepower" in the charger department to do what needed to be done. I have been using an Argus 48/50 rectifier/charger which is current limited to 55.2A. I don't think it was enough current to be able to sufficiently charge all 16 batteries. One time, I tried to lightly equalize them using 14.4V for 8 hours. I didn't have the guts to do the Lifeline recommended equalize 15.5V for 8 hours. I've had a Battery Life Saver BLS-48 desulfator on the battery bank for close to a year, and I don't think it has been powerful enough to do much on these badly sulfated batteries. When it was all said and done, the best resting voltage I would see on these batteries would be 50.4V after sitting overnight. In other words, I'd "fully charge" them using the Argus charger and then check resting voltage after about 8 hours (overnight). 50.4V resting voltage equates to around 2.1vpc. This did not seem good to me.

So, I just disconnected my 16 batteries today and set them up so I can charge/condition them individually. I have a BLS-12/24-B and I am using that along with an Inteli-Power 80A charger. I'm using a Xantrex Prosine SW1000 inverter to run a portable ceramic heater set to a 850W setting. I'm trying to cycle the batteries individually and then use the Inteli-Power 80A charger to get them charged. With 80A to work with each 105A/H battery, I know that I have enough "horsepower" to get a full charge on these AGM's.

I'm starting out by doing 3 cycles on each battery. Discharge at around 80A for 15 minutes, and then charge at 80A until fully charged. I'll see how it goes and decided how much to do to each battery. I plan to get them all up to a good resting voltage individually before I put them back together in the battery bank.

I've read about adding water and doing conditioning at higher voltages, but for now I'm going to try this route and see what the results are.

What's a good resting VPC that I could hope to see on these Lifeline AGM's?

- Edward

RCinFLA

Re: Sulfated Lifeline Concorde AGM Batteries

I would not do 80 amps of discharging and charging on those batteries (assume you mean each battery). 80 amps is going to stress them pretty badly.

25-35 amps for each battery is the most you should run on a continuous chg/dischg.

If you can get access to a pulse charger it may help. You can pulse at a higher current but keep the average rate down in the 25 amp range.

On sealed AGM's you want to avoid outgassing. You sometimes will hear a high pitched squeal during outgassing.

Starting from fully charged, do a 25% of rated capacity discharge, let them sit for couple hours then measure open circuit voltage to see what their SOC says.

Don't over do it. After three high current cycles allow a slow charge soak for several days.

I got some old AGM's taken out of commercial UPS that sat in warehouse for two years. They measured 11.5 vdc open circuit. I was able to get them back to about 85% of rated capacity with several cycles.

niel

Re: Sulfated Lifeline Concorde AGM Batteries

the self discharge rate on lifelines are around 2 or 3% a month, i believe. if at a 3% self discharge rate you could then roughly figure out the minimum length of time they were in storage. 60/3>20 months!!! concordes can take high charge/discharge rates, but 80a for 15 minutes is only 20ah taken out which would leave 105-20=85ah. 85/105=about 81% state of charge.
as to battery voltages you can see that in the section titled "knowing when to recharge" in this link,
http://www.lifelinebatteries.com/manual.php
note that the voltages listed are at rest voltages as i'm sure you already knew that.
you can roughly figure things out with the info on the link, but a predictable load test, once (if) the batteries reach a full charge, is warranted and concorde should state that somewhere on their website if not in this particular link the parameters they dictate for load testing. the battery charge voltage parameters are listed in this link to lay within 14.2v to 14.4v at 77 degrees f.
you may have to face that they may be severely compromised.
i did notice the charge efficiency is listed at 20% better than standard fla types. if fla types are 80% then this is 1.2x80=96% efficient.
do note the at rest voltage for 0% soc at 11.6v. that's the point they are considered dead.

keyturbocars

Re: Sulfated Lifeline Concorde AGM Batteries

Thanks a lot for the feedback guys. Lifeline says that these AGM batteries can be safely charged up to 5C. For these 105 A/H batteries, that'd be 525A @12V! Wow, that'd be one heck of a charger and some MONSTER cables! I figured that 80A charge/discharge should be safe.

Niel, I have come to the realization that they may be seriously sulfated and compromised. I'll see what I can do with them individually. With all 16 wired together in my 48V battery bank with a 55A charger, I just couldn't seem to do much. Lifeline recommends a minimum 0.2C charger for deep cycling, and that means I'd need 84A @ 48V. The best I can do is 55A with my current charger. I don't plan to regularly do deep charge/discharges, but rather just continue to keep them in float mode and divert extra wind power to my hot water heater, so I think the Argus 55A charger will be OK for occasional light charging.

RCinFLA

Re: Sulfated Lifeline Concorde AGM Batteries

They cannot be safely charged at 5C rate!

They will tolerate a short transient in-rush current of 5C amps.

keyturbocars

Re: Sulfated Lifeline Concorde AGM Batteries

You are right RCinFLA. I went back and read in the manual, and it's a 5C "inrush current". I remembered that wrong. The Lifeline AGM's can safely handle very large in/out currents, but not that MUCH on an extended basis!

I got tired of trying to manually cycle each of my 16 batteries individually, so I robbed a Inteli-Power 40A charger out of my travel trailer and set things up with a timer so that I am effectively discharging around 35A and charging back at 40A automatically over an extended period of time. I was experimenting with it and found some good times to cycle them automatically with the desulfator attached. I lightly cycled one battery yesterday for 8 hours and then finished off by charging it up. Resting voltage this morning was 12.64V. Not as good as the first battery that I more deeply cycled 80A in/out the other day. That battey is still resting at 12.68V even after a couple days. Need to do some more experimenting to find the best procedure to try to condition these batteries. I just need to come up with a somewhat automated system, as I can not sit there babysitting the whole time while doing this on 16 batteries.

keyturbocars

Re: Sulfated Lifeline Concorde AGM Batteries

Does anyone have a suggestion of a good battery voltage (while under 40a charging) to determine when the battery is fully charged?

I've got a Fluke meter attached to the battery while I have it set up for cycling with the desulfator. Right now, with the way I have the timer set, voltage climbs to around 14.25V while charging before the timer kicks in and turns on a load and begins to discharge the battery around 35A for 15 minutes.

I'm thinking that I probably need to let the charge time go a little longer to get up closer to 14.4V before the timer trips the 15 minute discharge load. I've got a plug in timer that can be set in 15 minute increments hooked to my Xantrex Prowatt SW1000 inverter. This runs a small heater to draw off around 75A. At the same time, the Inteli-Power 40A RV converter/charger is on all the time, so I figure I'm effectively discharging around 35A.

keyturbocars

Re: Sulfated Lifeline Concorde AGM Batteries

Learning new things while messing around with these sulfated Lifeline Concorde AGM's. Yesterday, I was trying something different. I hooked up 4 of the batteries in series and began charging them with the desulfator on the small battery bank. I checked battery voltage on each battery, and 3 of them were pretty close in terms of voltage, but 1 of them was showing really high voltage (15.7V). If I put my ear on top of the battery, I could hear some light bubbling on that battery.

I've never seen that sort of situation with one battery so much higher than the rest. Obviously, makes me think something is up with that one battery. Actually, something is "up" with all these batteries. Also makes me think that maybe it would be better to set up some of these batteries in parallel. Instead of 4 batteries set up in series for 48V, then perhaps 4 batteries in parallel for 12V and try desulfating them that way. Maybe then I won't "cook" certain batteries that are charging at higher voltages (like I saw yesterday).

One of the things I've learned is that getting a bargain on old batteries is NOT necessarily a bargain at ALL! Painful lesson. I know the primary problem is bad sulfation, and perhaps other problems (grid corrosion) I've caused over the past year trying to charge this unequal battery bank. Time will tell how many of these I can bring up to a useful capacity. I'll also see if "desulfators" do anything. Right now, I can't say that they do squat (at least for my batteries - so far).

BB.

Re: Sulfated Lifeline Concorde AGM Batteries

Series connections are good--because you KNOW the current is flowing through all X batteries.

What we don't know is why the one battery had high voltage during charging.

• Could be high because it was 100+% charged, and other batteries where way less than 100% charged. The fully charged one is now converting the energy into H2 O2 gasses while the other simply charge.
• Could be the one battery with excessive sulphation. Little active surface area on plates forcing high current densities and high "resistance" to raise battery voltage. Perhaps simply "no good" if vigorous equalization does not "cure problem".

Measuring resting voltages (2-5+ hour resting voltage is proportional to specific gravity--low state of charge or high sulphation should depress resting voltage) and charging "unmatched" batteries/cell singly are the next options.

Why series equalization should only be performed on "matched" and "fully charged" battery banks.

-Bill

keyturbocars

Re: Sulfated Lifeline Concorde AGM Batteries

Good points Bill. Makes me cringe thinking that for the past year I've had these all set up in a 48V bank and probably "cooking" certain batteries and causing permanent damage (plate corrosion) every time I tried to charge the bank. Live and learn. I got into this whole RE thing very ignorant and low on cash to spend, so I'm learing some things the hard way! I guess that's the way it goes sometimes. No one is born an expert in any area... gotta start somewhere. Learn by mistakes too.

BB.

Re: Sulfated Lifeline Concorde AGM Batteries

We all learn from our mistakes... That is why we sometimes call the first bank of batteries the "Training Batteries" because most of us have, or will, kill them before their time.

It is really hard to do solar GT/off grid solar/generators with little in the way of funds... It is expensive power (unless you don't have a utility nearby--then it is the only source of power).

About the only advise I can give to people here is to ask questions first and draw the design out on paper before buying bits and pieces. It will not only save you money in the long run--it usually gives the owner a good understanding of how the system works and what to watch out for--Hopefully avoiding some of the more common first timer mistakes.

-Bill

keyturbocars

Re: Sulfated Lifeline Concorde AGM Batteries

As a last ditch effort, if I were to try Lifeline's Equalization recommendation of 15.5V for 8 hours, then would it makes sense to hook batteries together in parallel?

My understanding is that it would be important to keep the voltages equal. Right now, when I hook 4 of the batteries in series to try to work with them as a mini-bank, I get too much variation in voltage. For example, when charging, I might have one battery at 13.2v and another at 15.5v. If I hook them up in parallel, then in theory I should be able to hold the voltage constant across each one.

I guess my goal is to try to sort through the 16 batteries that I have and try to come up with a decently matched set. It will have to be in multiples of 4 for my 48V system. Obviously, I'd like to utilize all 16 batteries, but that might not be possible. Next best would be 12 batteries, or 8 batteries, etct .... basically I'd like to get a 48V bank back together in the near future, and then try to continue to work with the other batteries offline with desulfating. If they ever come up to a decent level, then I might incorporate them back into my bank.

I have the Argus 48V rectifier which I can precisely set the charge voltages and adjust the amp output, but right now it looks like I can not work with these batteries in banks of 48V yet. I don't have a 12V charger which I can precisely set charge voltage. I'm stuck with "automatic" type 12v chargers. Not sure which 12v chargers are available that would be user programmable if I were to try to run a 15.5V equalization charge as Lifeline recommends for sulfated batteries.

I know that parallel connections are not best long term, but I am wondering if it makes sense for short term charging of batteries or conditioning/equalization?

BB.

Re: Sulfated Lifeline Concorde AGM Batteries

I will give the "long answer" (not that my answers have ever been short :roll:).

Connecting batteries in series is fine when you are "pumping current"... All cells will get equal amount of current.

If you are trying to "match charge batteries" -- The higher charged batteries will have a higher series voltage and start equalization / gassing themselves (as you have seen--the "good batteries" may over equalize and the bad ones not equalize the full 8 hours--It all depends how well they matched at the beginning of the charging cycle).

Connecting batteries in parallel for charging at a set voltage is probably the better match for the vendor's instructions (of course, even a 12 volt battery has 6 cells in series--so you don't have the ideal "pure voltage" charging setup anyway.

Drawback will probably depend on the ability of your charger to supply sufficient current to maintain your 15.5 volt setting (one battery may be fine, 16 batteries, not near enough current).

In general, 5% (of the 20 Hour Amp*Hour rating) seems to be a common ground for "equalization" current... If your charger will supply 5% of 4 batteries in parallel--it is probably worth a try.

The issue of how many batteries in parallel is probably more a factor of available time (16 batteries one at a time is 16x8=124hours of charging--most of a week).

If you are monitoring current--without a clamp on DC amp meter--it is difficult to see which of 4-16 parallel batteries are accepting current by monitoring the charger's amp meter (and may be "good") and which batteries are simply in high resistance, low current (and may be "bad").

I believe there is no difference for the batteries (and the quality of their charging) if they are charge in parallel groups or one at a time (assuming the charger has enough energy to keep the 15.5 volt set point for more than one battery in parallel).

-Bill

westbranch

Re: Sulfated Lifeline Concorde AGM Batteries

wow 15.5 V... for 8 hours

I just checked the values for an EQ on my AGM and they are

a min 13.2 V
max 14.1 V

continue charging until there is no drop in current for 3 hours

THEN

continue to charge for another 12 hours @ 14.1 V
OR 24 hours @ 13.8 V

just an FYI

hope it helps

PS,
I have a Xantrex charger that can be set to 14.7 V (COLD battery setting) max. Maybe that type would work for you on a slower EQ. ??

What are the max V settings for a Bulk and Absorb charge?


Eric

BB.

Re: Sulfated Lifeline Concorde AGM Batteries

There are one or two vendors out there that recommended the "elevated" equalization voltage for desulphating their AGM's... And that their AGM's are very capable of withstanding over voltage charging anyway...

A couple of the limiting factors I would monitor (don't charge at 15.5 volts in the middle of the living room and go away for a couple days) is battery temperature.

You can get elevated temperature from around the battery caps (where the catalyst is typically) as the recombination of H2 and O2 back to H2O (which liberates heat even with catalysts).

Second would be the battery plate area--Since the energy is not going into recharging the battery itself (80-90%+ efficient)--the Power=I*V has to be converted to heat (and gassing).

It sounds like a good way to end the life of an AGM--But one or several vendors do recommend it for attempting to repair sulphation--Which would have been a scrap battery anyway.

And here is a great thread from DapDan with information on how one place recommends to restore AGM batteries (new catalyst caps, adding water to cell, etc.):

Low rest voltage on GNB absolyte IIP cells

May not work for the average shade tree mechanic--but it is interesting.

-Bill

RCinFLA

Re: Sulfated Lifeline Concorde AGM Batteries

You will vent AGM's at 15v for 8 hours.

Do it only if absolutely needed.

Watch the end sides of battery. They will bow out from pressure buildup.

In the end you need the series connected battery to match.

keyturbocars

Re: Sulfated Lifeline Concorde AGM Batteries

Thanks Bill and Eric for the helpful information!

If I try to do the 15.5V @ 8hr equalization, then I'll need to find myself a different 12V charger where I can set the voltage to 15.5V and keep it there.

I tried another idea of trying to match some batteries in a 4 battery bank so I could use my Argus 48V charger. I used my new load tester and I did the 15 second load test on each battery. I set it to the recommended 300A and kept it there for 15 seconds. I had my Fluke multimeter hooked up and took BEFORE and AFTER readings. After the 15 second test, I was able to find the voltage drop across each battery. I was able to record that data on each battery. Now, I think I will try to group together a set of 4 in series that had similar voltage drops and see how they charge in series with the Argus 48V charger.

I figured that the voltage drop would give me some indication of internal battery resistance and therefore amount of sulfation. I have voltage drops ranging from 2.08V to 2.65V. The one that had a drop of 2.65V is one that I know is problematic and has a low resting votlage. So, perhaps the voltage drop will give me a starting point for grouping some of these together and see what I can do with my 48V charger.

If that doesn't work, then I'll need to find myself a 12V charger up to the task of doing some parallel bank charging. Need something where I can set it to 15.5V and also have enough amps to be able to charge multiple batteries in parallel. Bill, I do have an old TIF Instruments DC Clamp on ammeter.

The 15.5V for 8HR procedure is a last resort for me. I don't want to do it unless I'm ready to toss the batteries. On some of these, they have a decent resting voltage (12.6-12.7V) and lower voltage drop (2.08-2.15V), so think I'll try to work with those with gentler methods. If I sort out some bad batteries that will not respond to gentler methods, then I might try the more drastic Lifeline equalization.

Eric, Lifeline recommends 14.4V bulk/acceptance and 13.3V float voltages.

Thanks for the helpful advice!

Edward

westbranch

Re: Sulfated Lifeline Concorde AGM Batteries

Ed, FYI GNB recommends:

Absorb Voltage to be between 13.68 V and 14.28 V and

Float at 13.32 V to 13.62 V
with an absolute max of 14.1 V regardless of temperature.

so it sounds like they are very similar.

Discussion with a local GNB rep was, due the age/condition of my battery, to use the upper levels

Eric

keyturbocars

Re: Sulfated Lifeline Concorde AGM Batteries

Thanks for the voltage info Eric.

Right now, I need to find a proper 12v charger so I can do some better individual battery charging.

I sorted some of the batteries and tried to hook them up in groups of 4 trying to match them as much as possible since I have more options for charging with 48v right now. The problem I am still encountering is that if I try to bulk/absorb charge, I get too much variation in battery voltages. I think I am going to have to do more individual battery charging and keep sorting/matching.

I must admit that I had no idea what I would be getting into with these new (but "old") AGM's. What a pain in the neck (and back for having to pick them up and move them around so much). If I had known this, then I would have never bought them.

Just trying to make the best of it now.

Edward

westbranch

Re: Sulfated Lifeline Concorde AGM Batteries

Ed, I was thinking about your set up and noticed you have not added a description to your sig line, it would help knowing what components you have...

Anyway the Xantrex TC 40+ charger has 3 outputs, so it can charge 3 batteries at once, problem wold be they all would have to be "identical" as to the charge regime needed. Due to the disparity in battery state, I am thinking that you will need to do one at a time. Should be able to find a used TC 20 or 40 charger on Ebay. the 40 needs a 3000 W genset to startup when it puts out just over 40 A.
There is a 20 A model in Texas on Ebay right now.

Do you have a MPPT CC?

Eric

westbranch

Re: Sulfated Lifeline Concorde AGM Batteries

Also a TC40 in Vancouver Craigslist for $100

e

keyturbocars

Re: Sulfated Lifeline Concorde AGM Batteries

Thanks for the help Eric. I did some reading on the Xantrex TrueCharge2 chargers, and they can be set up to 16.0V charging output. So, if I decided to do the Lifeline recommended 15.5V equalization charge on these, then I could use this charger. Right now, I am going to try to deal with charging each battery individually. I do have 2 Inteli-Power chargers/converters (oen 40A and one 80a) that are normally used in RV's. Both have the "charge wizard" that makes them 3 stage chargers. Max voltage output is 14.4V and it's all automatic (will switch to float mode), so I could not use them to equalize. But, I can use them to try to charge some of the batteries in parallel or individually. The current tapers way down as batteries charge.

You are right that sometime I need to add some of my equipment to my signature. I do have a Morningstar TS-45 MPPT controller that I plan to use with 6 x 130W panels, but I have not done any install work yet on my solar. My other controller for the 2kw wind turbine, is a dump/diversion load type.

Thanks again for pointing out the Xantrex TrueCharge chargers. They look like what I'd need if I was going to try the equalize procedure.

Is your TrueCharge made in Canada?

I'd be willing to be that the new TrueCharge2 chargers are made in China.

Just curious...

Edward

westbranch

Re: Sulfated Lifeline Concorde AGM Batteries

Not sure where they are made as X has been bought out by Schneider(sp?) electric.

As far as I know X was/is headquartered in Vancouver and goods built/assembled in Washington state.

there are some threads on the board about this takeover and availability of product... can't think of where right now.

Eric

icarus

Re: Sulfated Lifeline Concorde AGM Batteries

A lot of Xantrex stuff has been built off shore for a long time now. QC has been somewhat suspect from what I have heard.

That said, I love my TC series chargers. Don't know anything about the newest editions however. I hear they are hard to source.

Tony

keyturbocars

Re: Sulfated Lifeline Concorde AGM Batteries

Yes, I wonder about the quality of the new stuff. I have a Xantrex SW1000 inverter that says on the box that says something like "Designed in Canada and Made in China".

It works fine, but I haven't used it much. Because of my mechanical engineering background (don't work in the field any more), and the way my brain is wired, I usually get an impression of quality of products. My impression of the SW1000 is that the quality is "good", but not the high quality impression I get from equipment that holds up over the long haul. I know that "impressions" are just that... impressions. Time will only tell. Even so, I'd bet the older stuff made in US or Canada would be much higher quality.

MisterB

Re: Sulfated Lifeline Concorde AGM Batteries

keyturbocars wrote: »

Yes, I wonder about the quality of the new stuff. I have a Xantrex SW1000 inverter that says on the box that says something like "Designed in Canada and Made in China".

I Even so, I'd bet the older stuff made in US or Canada would be much higher quality.

Just for reference: I have 2 Trace/Xanthrex C-30A+ controllers. One is an earlier Trace model made in America and one is a later Trace/Xanthrex version of the same controller more than likely manufactured in China with the Trace design. The electronics are identical but the older Trace controller has both a heavier guage metal chassis and a heavier guage circuit board and the Trace controller has the label painted on the front of the cover plate and technical info painted on the inside of the the cover plate while the Trace/Xantrex version has plastic stickers instead.

Older Trace inverter/chargers like the 2012 are competitive items on ebay these days. The older Trace controllers much less so. I've bought a couple of them for less than $10 a piece recently on ebay. They are primitive, yes, but built to last a liftetime. I am experimenting with the very first Trace controller, a C-30 Quad Voltage Controller on which I did a couple of small mods and connected to a small inverter, to automatically turn on useful loads like a small electric cooler when my panels and/or wind turbine are outputing and the batteries are charged. It is a simple and very rugged piece of equipment and, as experiements go, this one so far is working very nicely.

keyturbocars

Re: Sulfated Lifeline Concorde AGM Batteries

The old saying, "They don't make 'em like they used to" seems to be valid in many cases these days!

keyturbocars

Re: Sulfated Lifeline Concorde AGM Batteries

Speaking of "they don't make 'em like they used to"....



I just picked up a brand new Ratelco 12V constant voltage charger/rectifier. It was manufactured in 1995, but still new in the box. Good ole' made in the USA! Cost $145 & $38 for shipping.

I searched and could not find any other charger that I could set to EXACTLY 15.5V for the Lifeline recommended equalization procedure. The Xantrex TrueCharge chargers all show 16.0V equalization. Other chargers seem to have equalization voltages that are too high or too low. Trying to trick a 3 stage charger into 15.5V for bulk for 8 hours seemed unlikely. In order to carry out the Lifeline 15.5V for 8 hours procedure exactly, this is the only thing I could find other than the $4700 CA1550 Battery Analyzer/Charger.

This thing appears to be built like a tank. 65 lbs for a 12V 6A charger! The 6A apears to be just about right for doing the equalization on 1 battery. If I go with 5% of 105A/H, then that's 5.25A, so this should be just about right. I'll use my Fluke multimeter to precisely set the output voltage to 15.50V.

http://www.recycledgoods.com/products/Ratelco-FF1263-A-Constant-Voltage-battery-charging-system-Rectifier.html

I called and talked with Lifeline today about my batteries, and they told me that their AGM's are NOT like all the others. He said people make the mistake of lumping all AGM's together. He said if the equalization is done exactly as they say, then there should not be any venting (unless there are serious problems with the battery). I've got one particularly "bad" battery that I can't get the resting voltage above 12.50V. When I discharge it, voltage drops quickly and capacity seems to be much less than others. I think I'll try the equalization on this one first and see what happens. I consider this battery a "lost cause" already, so it's worth experimenting on first. If I mess it up, then no big loss. If it recovers, then it'll be a big gain! The charger costs about 1/2 of what one of these batteries costs new, so it's worth a try.

Edward

westbranch

Re: Sulfated Lifeline Concorde AGM Batteries

looks good. I think I would start with the worst battery and, after a regular 3 stage charge, EQ charge at about 14.4 v from your new (neat) toy and carefully record all your readings over X hours, let sit for 4 - 5 hours test voltage and then apply a fixed load and record again... you should know quite soon if you have made progress. Do you have an Infrared temp sensor? you can monitor temp also.
If no significant change, up the EQ voltage a bit
good luck
Eric

keyturbocars

Re: Sulfated Lifeline Concorde AGM Batteries

Good idea on monitoring the temperatures. I do have an IR temp gun that I can use.

westbranch

Re: Sulfated Lifeline Concorde AGM Batteries

just thinking, you might be able to identify a single 'hot' cell during a normal charge using the IR gun... and identify where to check for abnormal temps on that battery.. vs the other cells when doing an EQ.

ie if that cell is headed for thermal runaway you might spot it early

ej