Lifeline AGM Charging Conundrum

[MsNomer]

250Ah Lifeline AGM a few months old
Alternator Charging, PM provides 14.2A
300W Solar
NOCO Genius26000 AC Charger
Trimetric Meter and Solar Charger set to Lifeline Parameters

Loads ~ 40A per 12-hr overnight (fridge, freezer, MW, etc) Harder to measure daytime because of solar input.

The problem is that the battery voltage hovers at 13.1-2 anytime they have the least bit of sun. This means the NOCO thinks they are full, and thus just sits there happily blinking its green light. This also means that solar and alternator charging are slow as Methuselah. (Trimetric Absorption Voltage set to 14.4)

Lifeline says they must be fully charged if they are at 13.1, yet they can’t be if I just ran them down and they are accepting several amps—according to Lifeline's literature, they are not full if they accept more than 0.5C (1.25A). Lifeline accuses the Trimetric of false voltage/amperage readings, but we have checked both independently.

This past week, plugged in at the driveway, it took the entire week to charge from 95 to 100%. (Fridge and freezer shift to AC when shore power available, so loads were minimal.)

We are seriously scratching our heads and appreciate any wisdom.

[booster]

Originally Posted by MsNomer

250Ah Lifeline AGM a few months old
Alternator Charging, PM provides 14.2A
300W Solar
NOCO Genius26000 AC Charger
Trimetric Meter and Solar Charger set to Lifeline Parameters

Loads ~ 40A per 12-hr overnight (fridge, freezer, MW, etc) Harder to measure daytime because of solar input.

The problem is that the battery voltage hovers at 13.1-2 anytime they have the least bit of sun. This means the NOCO thinks they are full, and thus just sits there happily blinking its green light. This also means that solar and alternator charging are slow as Methuselah. (Trimetric Absorption Voltage set to 14.4)


Lifeline says they must be fully charged if they are at 13.1, yet they can’t be if I just ran them down and they are accepting several amps—according to Lifeline's literature, they are not full if they accept more than 0.5C (1.25A). Lifeline accuses the Trimetric of false voltage/amperage readings, but we have checked both independently.

This past week, plugged in at the driveway, it took the entire week to charge from 95 to 100%. (Fridge and freezer shift to AC when shore power available, so loads were minimal.)

We are seriously scratching our heads and appreciate any wisdom.

If they are at 13.1v rested for overnight with no charging or overload, I agree with Lifeline, but any charging like solar or loads during that time will screw up the voltage.



Probably not what you want to hear, but you are seeing a very typical thing with most systems, but most people don't know it is happening. Most of the charging sources look at the battery voltage and decide whether to do a full charge or not, and that voltage is fairly low for most in the 12.6v range. They do this to prevent overcharging, I think. Lifelines hold high voltage for a long time so very common issue with them.



There are very limited things you can try to fix it and only a couple I know will work for some components.


The NOCO, I don't know how they terminate the charging when it will do a full charge. If anyone knows how they do it, that would help to see if anything can be done to fool it into charging.


If you are charging with the Trimetric solar controller, and if you can get it to start charging, it might run the full cycle as I think the solar controller will charge until it meets your set "full" specs, which would probably be 1.25 amps and 14.4v at the same time for the Lifelines. It may also have a setting for the minimum start voltage for full charge or it may be called a rebulk voltage threshold that will ask for voltage and time at that voltage. Those settings, if it has them, are there so if you had a big fast discharge that drained you full battery during the day, the controller would go back into bulk mode and go to a full finishing charge at 14.4v and 1.25 amps. You should be able to simulate that load and voltage drop by running a high amp load and having the voltage set pretty high to start and/or rebulk.


If you have a single alternator, you are at it's mercy because it is controlled by the van electronics. You can put a B to B charger on it, but you will have the same issue with them as the other sources, and they may or may not be able to be fooled into starting.


What we have done to minimize the problem.


We have a Magnum MS2000 inverter/charger with ARC50 remote and BMK shunt based monitor setup. It does full volt/amp termination charging from it's internal monitor so always charges to the specs we put in for our 440ah of Lifelines. We use 14.3v and 2.0 amps. But, just like all the other chargers, it looks at voltage at startup and will go to float. Luckily, it also has a manual control that is a couple of button pushes on the remote and that will force it to run a full charge. If the batteries are full and meet the settings it may only run 5 minutes to confirm they are full to setpoints. Downside is that I have to remember to look to see if it went right to float if the batteries and close to full. The Magnum is the only charger I know of that will charge this way to get consistently full without overcharge.


Our solar is a Blue Sky MPPT with Pro remote and it also runs off the same shunt as the Magnum and will also charge to volt and amp settings the same way. It looks at the voltage at start and if it is below the 12.8v setpoint they use it will do a full charge, if not it goes to float. It will also rebulk if it goes below the float setting which can cause other issues that aren't related to the topic here but at least it is easy to cause it to do that with a moderate load as the float is above the 13.1v the batteries sit at.


We have two parallel alternators running of a remote regulator. It is an Ample Power regulator made by Charles, but no longer available. It allows me to set voltages and times for multistage charging but doesn't control by amps, just algorithm, so not accurate charging. It does, however, allow stage forcing like the Magnum, so I just have an accurate ammeter to the coach batteries display on the dash and can force absorption and charge until I hit 2.0 amps or turn it over to solar to finish by shutting off the alternator to batteries charging.



Our system works well, but was not inexpensive to do and is certainly not prefect. Only custom programmable controller use would probably be lot better or a centralized control complete system from Victron or others like they use on yachts.


Possible improvements that aren't real expensive would be to get a Progressive Dynamics charger with pendant control Charge Wizard. The Charge Wizard allows you to force stages, but you also have to watch your monitor to know when to take it to float. If used carefully, it will a very good job of charging, as well as the Magnum, but be a lot more effort.


The solar you might be able to fool, so still undetermined, I think. It might be interesting if you could list all the settings you have put in so I can look at the manual and see if there is anything else that can be done. You could also test the voltage drop generating at startup or during the day to rebulk.


For the engine charging, the factory alternator will probably stay fairly high in voltage, at least for a while so it may or may not be capable of getting the batteries full. If it does hold above 14.1v or so it will get them full, but could overcharge on long drives of over 5 hours or so. Watching the amps on the Trimetric will allow you find out what it is doing so you can determine what to do. You have solar that does accurate charging so it can finish the charging for you once close so a shutoff of alternator to battery charging might be in order.


Sorry about the length, but this is not a simple thing to address, I fear. Good luck in whatever you decide to do.

[GeorgeRa]

Originally Posted by MsNomer

250Ah Lifeline AGM a few months old
Alternator Charging, PM provides 14.2A
300W Solar
NOCO Genius26000 AC Charger
Trimetric Meter and Solar Charger set to Lifeline Parameters

Loads ~ 40A per 12-hr overnight (fridge, freezer, MW, etc) Harder to measure daytime because of solar input.

The problem is that the battery voltage hovers at 13.1-2 anytime they have the least bit of sun. This means the NOCO thinks they are full, and thus just sits there happily blinking its green light. This also means that solar and alternator charging are slow as Methuselah. (Trimetric Absorption Voltage set to 14.4)

Lifeline says they must be fully charged if they are at 13.1, yet they can’t be if I just ran them down and they are accepting several amps—according to Lifeline's literature, they are not full if they accept more than 0.5C (1.25A). Lifeline accuses the Trimetric of false voltage/amperage readings, but we have checked both independently.

This past week, plugged in at the driveway, it took the entire week to charge from 95 to 100%. (Fridge and freezer shift to AC when shore power available, so loads were minimal.)

We are seriously scratching our heads and appreciate any wisdom.

Did your system work well with the previous battery? Is your Noco a multistage charger?

This is a good place to get chargers. https://www.bestconverter.com/804-12...l#.YMPBm_lKguU

[booster]

Originally Posted by GeorgeRa

Did your system work well with the previous battery? Is your Noco a multistage charger?

This is a good place to get chargers. https://www.bestconverter.com/804-12...l#.YMPBm_lKguU

I just took a look at the 50 amp NOCO specs and it appears to make the standard "perfect" charging algorithm they all seem claim. They also say a 200 ah battery will take 3-4 hours to charge, so we know they are not correct in their claims of full, at least to battery manufacturer's specs for full.


Their doesn't seem to be any way to force the stage back to bulk when it says it is done, but you might be able to fool it into starting with load, but then the algorithm might kick it right back into float once the load was off.

[MsNomer]

Thanks, guys, for at least reassuring me I’m not crazy.

I don’t have an easy way to apply a decent load on the batteries while charger is on because on shore power, fridges and all AC switch to shore. I can disable solar.

I will explore Trimetric instructions for possible higher level settings.

[GeorgeRa]

Originally Posted by MsNomer

Thanks, guys, for at least reassuring me I’m not crazy.

I don’t have an easy way to apply a decent load on the batteries while charger is on because on shore power, fridges and all AC switch to shore. I can disable solar.

I will explore Trimetric instructions for possible higher level settings.

Did your system work OK before installation of the new battery?

NOCO Genius26000 AC Charger seem as good automotive battery charger. One review I found was for Jumpstarter chargers. https://www.jumpstarterreviews.org/n...and-beneficial. Perhaps this is your system weak link.

[MsNomer]

Thanks, guys, for at least reassuring me I’m not crazy.

I don’t have an easy way to apply a decent load on the batteries while charger is on because on shore power, fridges and all AC switch to shore. I can disable solar.

I will explore Trimetric instructions for possible higher level settings.

[markopolo]

What criteria did you set on the Trimetric monitor to indicate charged batteries?

It's possible that a new charger might not be able to meet the criteria either if too high of a goal. For example, I would have liked 14.4V & 1A on my older Trimetric but had to settle for 14.3V & 1A because my PD charger could not meet the 14.4V 1A goal. Ideally I would have matched the equipment to the requirements but this seems to have worked. Sometimes the Trimetric shows over 100% SOC so 14.3v & 1A is less than 100% but I think it's good enough.

[booster]

Originally Posted by markopolo

What criteria did you set on the Trimetric monitor to indicate charged batteries?

It's possible that a new charger might not be able to meet the criteria either if too high of a goal. For example, I would have liked 14.4V & 1A on my older Trimetric but had to settle for 14.3V & 1A because my PD charger could not meet the 14.4V 1A goal. Ideally I would have matched the equipment to the requirements but this seems to have worked. Sometimes the Trimetric shows over 100% SOC so 14.3v & 1A is less than 100% but I think it's good enough.

It is always best if things match perfectly, but there are some places the match is more important than others, I think. The difference between 14.4 and 14.3v absorption would be a very small concern, if any at all, for me. As long as you are within a range above about 14.1v to even as high a 14.6v most of the data I have seen would indicate minor differences. Personally, I stay on the slightly low side of range on the settables we have at about 14.3v.


IMO, the 1 amp in your case or whatever the amps are to get to manufacturer spec for return, tail, ending, whatever they call it, amps is much more important as it is what is determining if the batteries are totally full and recovered.


It is also normal behavior for the Trimetric and other monitors to read over 100% on the recharge cycle, and they can also read under 100% when they the batteries are actually full. It is just mismatch of the constantly varying charge efficiency with the charge efficiency setting in the monitor. As soon as you start to discharge the Trimetric should reset and recalibrate to read 100%, whether it was over or under, for the discharge cycle accuracy to be right.

[MsNomer]

I set Lifeline’s criterion for full charge: 0.5C = 1.25A for 250Ah.

I am familiar with the phenomenon Booster describes. With my previous batteries, SOC might read, for example, 103%. Blip on the inverter and SOC would instantly reset to 100%.

We are presently beginning 3 weeks of Boondocking. I’ve added a second Engel fridge as a freezer, so the biggest load ever on the system. We made 97% yesterday on solar alone, never above 13.4, so by most people’s notion we are fine. Problem is, I know we are not really.

[booster]

I just took a look at the Tirmetric solar charger manual and technical manual at the Bogart site. The tech manual is only online and wouldn't have come with the unit, AFAIK.


It seems to say the unit will run a full charge cycle at every initiation, but not certain because of terminology about what an already connected but coming out of night sleep. It also shows some timers and such and things that change with 3 or 4 stage settings. Trimetric stuff tends to have a lot of settings, and capability, but can be confusing sometimes to fully understand. What I didn't find and was looking for was a fully setting list on one document for the meter and solar together, as that would be very handy to have. I do think it would interesting to see the full list of settings for Msnomer's system to see how they line up with another look at all the instructions and setting descriptions.

[markopolo]

Originally Posted by MsNomer

I set Lifeline’s criterion for full charge: 0.5%C = 1.25A for 250Ah.............

What voltage did you choose? Is it the 14.3V the current Lifeline manual indicates (± 0.1)?

[booster]

Originally Posted by markopolo

What voltage did you choose? Is it the 14.3V the current Lifeline manual indicates (± 0.1)?

It looks like Lifeline has really tightened up the voltage spec. I seem to remember +/- .2v in the past and even some spec sheets at 14.1-14.6 volts for a while. Very interesting.

[MsNomer]

I literally had a Lifeline rep on the phone as I verified each setting with him.

[markopolo]

To be able to determine if a battery is being fully charged or not we first have to know what voltage plus ending amps we're trying to meet.

It's possible that MsNomer's Trimetric charged indicator criteria is too high. I say it's possible because it was mentioned that it took an entire week for the batteries to get to 100%. Criteria that's too high could explain that. Other reasons include charging equipment that is not up to the task and/or loads that interfere.

Step 1 is determining the charged indicator criteria and that criteria is a combination absorption voltage and tail current. One data point without the other is of no use when trying to figure out if a battery has reached full charge or not.

[booster]

Originally Posted by markopolo

To be able to determine if a battery is being fully charged or not we first have to know what voltage plus ending amps we're trying to meet.

It's possible that MsNomer's Trimetric charged indicator criteria is too high. I say it's possible because it was mentioned that it took an entire week for the batteries to get to 100%. Criteria that's too high could explain that. Other reasons include charging equipment that is not up to the task and/or loads that interfere.

Step 1 is determining the charged indicator criteria and that criteria is a combination absorption voltage and tail current. One data point without the other is of no use when trying to figure out if a battery has reached full charge or not.

I think his parameters are good as he knows his tail amps spec, but as I mentioned always good to see the whole list.


I think the reason it took a week to get to 100% has nothing to do with the monitor. It was stated that his charger is going to float right way, and the solar is not keeping up, it appears, based on it not getting to full voltage. At float the charge is very slow with much of the input just going it maintaining. The monitor keeps adding the amp hours as they tally, and if you are on float long enough without a discharge to reset you can get a very large % after a couple of months on float.


My guess at this point is the charger probably won't every work to full unless the discharge is deep enough to put the batteries below 12.6v, and that there may be some max timer setting not letting the solar finish the charge by running out of time before the charge is done.

[GeorgeRa]

Many, many years ago I attended great week-long course of troubleshooting by KT. One of the key questions demanding an answer was what has changed. So, in this case the system was working fine until battery replacement, I assume, still don’t have an answer.

[markopolo]

If comfortable with manual monitoring & intervention of the recharge process then two alternate modes on the G26000 may be of use for grid based charging in Mr & MsNomers van.

https://www.batterymart.com/manual/g26000-manual.pdf

The first is the 13.6V 5A power supply mode.

The second is the 14.2V 26A lithium mode. My assumption/expectation here is that lithium mode ignores all or most of the PbA algorithm. It would have to be monitored via the Trimetric if used. You'd have to manually switch the g26000 back to 12V normal mode when tail current drops to around 1 or 2 amps. 14.2V absorption all the way down to 1 or 2 amps meets the low side of Lifeline's recommendations.

[MsNomer]

Marko, that is exactly what I proposed to the NOCO rep and he nearly went ballistic. I kept asking for a reason why it wouldn’t work, and he just kept repeating that AGM and Lithium are different. Maybe he was just covering his a__? When I next have the opportunity to plug in, I believe I will try it.

On our 5th day of Boondocking, we are fluctuating between 85 and 97% on solar alone. Pretty darned good, I’ll say, for having just added a 22qt freezer.

[markopolo]

Did some Google searching various forums. It appears that the Noco lithium mode charges to approximately 14.2V then quits & restarts charging when battery voltage drops to around 12.7V. If so, that's safe for AGM but inadequate as there's no absorption stage. It could be thought of as being a PbA Bulk stage which is the stage prior to absorption. Lithium mode still might be useful if another mode or your solar setup can take over and finish the charge cycle.