Magnum Inverter question; AGM 1 or AGM 2???

[Steve P]

I'm trying to determine whether I should use AGM 1 or AGM 2 on my Magnum inverter to charge my batteries. Both the house and the chassis are AGM batteries that came with the coach. I suspect they are about 3-4 years old. Both of them have AGM on the label. I called Battery Source who supplied them, and got someone who had to ask someone else. They said they didn't really think it mattered whether I chose AGM 1 or AGM 2 on my charger. From reading various places, I doubt that that is true. Any idea how I can make this determination?  It is currently set to the default (Flooded) of course.

[Bill R]

I spoke one time with Magnum tech folks going over my settings and they suggested AGM2.  I have Duracell AGM 205 AHrs. 

[Tom Cherry]

On 2/1/2023 at 6:04 PM, Bill R said:

I spoke one time with Magnum tech folks going over my settings and they suggested AGM2.  I have Duracell AGM 205 AHrs. 

 

On 2/1/2023 at 2:25 PM, Steve P said:

I'm trying to determine whether I should use AGM 1 or AGM 2 on my Magnum inverter to charge my batteries. Both the house and the chassis are AGM batteries that came with the coach. I suspect they are about 3-4 years old. Both of them have AGM on the label. I called Battery Source who supplied them, and got someone who had to ask someone else. They said they didn't really think it mattered whether I chose AGM 1 or AGM 2 on my charger. From reading various places, I doubt that that is true. Any idea how I can make this determination?  It is currently set to the default (Flooded) of course.

 

When in doubt….take a picture of the battery and then do your research and then call Magnum.  It would be great if you could post some info about when to use AGM 1 vs AGM 2 as many are going down that path..  It might also depend on which remote you have.  I had to buy a new remote and the settings and the menus were about 50% the same….but the rest was almost “Greek” until I studied the manual and started to understand the changes in the screens and the new features.

Would be good also to know which remote (I’m assuming the simple one and not the one capable of supporting the BKM  BMK) you both have.  Also what does the manual say or explain?

Looking forward to reading and learning.

[TomV48]

When I was limping along charging my lifepo batteries with the AGM setting I had trouble determining any difference between the two.

When I finally upgraded my Magnum to the lithium generation I had to replace the motherboard inside the Magnum at about $200 and replace the control head on the wall and I now have custom settings as well as lithium presets but I still can't decipher any difference between AGM 1 and agm2

I didn't get anywhere trying to call Magnum but I was able to email them and I did get a reply telling me what I had to do with my particular unit including what to do to get the upgrade going and where to get the parts.

[Bill R]

59 minutes ago, Tom Cherry said:

Would be good also to know which remote (I’m assuming the simple one and not the one capable of supporting the BKM) you both have.

Good point Tom.  I have the original installed ME Series Magnum Inverter/Charger with the original installed ME Series Remote Control.   Magnum Tech really didn't explain why but said they recommend AGM2 for my set up,  I had been running them on AGM1 and after I switched to AGM2 I believe I did see better charging performance of the batteries.  Again, I can not say why.  And the manual doesn't say why either.

 

ME Series Remote Manual Pic.pdf

[Steve P]

3 hours ago, Bill R said:

Good point Tom.  I have the original installed ME Series Magnum Inverter/Charger with the original installed ME Series Remote Control.   Magnum Tech really didn't explain why but said they recommend AGM2 for my set up,  I had been running them on AGM1 and after I switched to AGM2 I believe I did see better charging performance of the batteries.  Again, I can not say why.  And the manual doesn't say why either.

 

ME Series Remote Manual Pic.pdf 85.77 kB · 7 downloads

My remote is even older and simpler... no AGS button, and I don't even know what BKM is. 

[TomV48]

Well just because I ran AGM too cuz it was the higher setting but I swear I couldn't tell a difference between it and a gm1.  No problem now I have my custom settings jacked right up to the lifepo batteries need

[Tom Cherry]

On 2/1/2023 at 11:18 PM, Steve P said:

My remote is even older and simpler... no AGS button, and I don't even know what BKM is. 

Don’t feel “undereducated”.  Magnum has a Battery Monitoring Kit (Google if this ain’t enough).  You install a high current shunt.  There is a special (ACR?) high tech remote that actually displays the State of Charge (SOC) on your batteries and gives those so inclined to want and digest such information a MUCH better picture or instantaneous display of their Batteries and their performance.

I choose not to get that deep or sophisticated…but others do.

I DO exercise my batteries periodically to keep them working properly….as recommended by Trojan.  I can easily see after a few 50% run down cycles and recharging what the SOC or the “health check up” is.

FWIW…aimed at the group and not you personally, we have many members that choose flooded cells as they are more robust or forgiving than AGM’s.  If you abuse or improperly charge AGM’s they fail much quicker.  We have members that easily get 8+ years from their flooded cells.

They do the PM and keep the electrolyte level up (Battery Miser Caps are their choice).  They exercise or do a 3 cycle 50% rundown semiannually.  Most are like me and have powered storage and have BiDirectional charging, so our Res Refers never run off battery when driving.

After you do the run down, you put a quick load on the batteries and then disconnect (pull the center jumpers).  You measure the voltage and check the Specific Gravity (using a tester what gives you numeric SG readings, not colors).  Then you use a SOC Table (Trojan has one in their Battery Operators Manual….which you can download).  Then you know that when Fully Recharged, your battery is still 100% or as new.  As the battery ages, the SOC or the voltage that it will have then, will decrease.  Typically, if your batteries reach 50% and you are not a heavy boon docker, you can still get a few more years.

By testing the voltage, you pickup if one battery has lost the lead oxide off one cell and it shorts our and you only have a 4.X VDC battery….in other words…TRASH.

In addition, you can see the variations between each cell in each battery and also compare battery to battery.  Once a cell begins to fail or lave really low SP readings (<50%]….that battery will not hold a charge and also is toast.

That's sort of the macro view….and the battery monitoring kit (BKM BMK ) tells you something is a miss.  BUT, you still have to isolate the particular battery and/or cell.  Catch a failed battery early and the rest is OK, you can replace it,  but the longer it is in the system, the greater the chance that it will imbalance it’s mate or the bank…so one or two can cause enough damage that you just replace them all.

My OEM Interstates had one shorted cell in one battery and a bad cell in another,  I use a two battery bank for a while and finally bought 4 new Trojans.  I got 8 or so years and they really weren’t that bad….that is how you keep your batteries in good health.

This is ALSO WHY learning how to use your Remote and properly setting it up is important.  That goes double or triple for converting to AGM without understanding that you must do a more precise setup and learn WHICH AGM mode to use….

There WILL be a Pop Quiz….LOL. 😈😂👷‍♂️💣

[saflyer]

On 2/1/2023 at 10:18 PM, Steve P said:

My remote is even older and simpler... no AGS button, and I don't even know what BKM is. 

Threw me too. I think he meant BMK, Battery Monitor Kit.

Edited February 3, 2023 by saflyer

[Ivylog]

15 years ago when I went to AGMs my research favored the AGM2 setting… don’t remember the difference and I only got 10 years out of them, dry camping most summers.

Recently went to Lithiums I’d assemble/built for $2/AH and the AGM2 setting only charges them to 99.8%. Biggest problem is that setting won’t start charging until they are down to 40%…thinks they are fully charged until 13.0V.

The best reason to go Lithium is for dry camping and the increased cycles they are capably of plus like AGM, no corrosion and mount in any orientation. Instead of spending  $200 RC-50L (Lithium) I’d buy an additional 100 amp charger that can be set to 14.6V. This will decrease your generator run time (AGM or Lithium) and let you start recharging sooner. I power mine off the block heater outlet.

 

 

[Tom Cherry]

2 hours ago, saflyer said:

Threw me too. I think he meant BMK, Battery Monitor Kit.

GUILTY as charged.  I edited my transposition error in the posts.  We have enough acronyms....should have been BMK...

Thanks....good sharp eyed folks....who read for content and understanding....

[Steven P]

@Steve P this is from the manual for my Magnum.  I have Trojan t105 agm and use agm2.  Please see diagram.

[Ivylog]

Interesting that the flooded absorption voltage of 14.6 is higher than any other battery type other than custom.

[Steve P]

All this info is very informative.   I think I will have to disconnect 1 house and 1 chassis battery and see if there are any clues or markings on them.   Sadly, nothing is visible on the top other than 31 AGM on one,  and a similar part number on the other.  I believe they have been charging on "Flooded" for 2.5 years since I've had the MH.  I don't know why the PO would have done that, or if that will shorten their useful life.  I might switch them to AGM 2, with some hesitation.  On top of that, I think my BIRD relay is non-functional and am reading up on how to test that.  There are a thousand threads on BIRD's, including one I've jumped in on previously, so let's not hijack this thread.

Thanks for the input everyone! 

[saflyer]

On 2/1/2023 at 1:25 PM, Steve P said:

I'm trying to determine whether I should use AGM 1 or AGM 2 on my Magnum inverter to charge my batteries. Both the house and the chassis are AGM batteries that came with the coach. I suspect they are about 3-4 years old. Both of them have AGM on the label. I called Battery Source who supplied them, and got someone who had to ask someone else. They said they didn't really think it mattered whether I chose AGM 1 or AGM 2 on my charger. From reading various places, I doubt that that is true. Any idea how I can make this determination?  It is currently set to the default (Flooded) of course.

Just watched a Magnum Energy video on setting up charging parameters with their ME-ARC remote. When discussing battery types they said AGM-1 is used for Lifeline batteries and AGM-2 for “most other brands”. That’s not something you can go on 100% but it’s worth noting.

[Steven P]

9 hours ago, saflyer said:

Just watched a Magnum Energy video on setting up charging parameters with their ME-ARC remote. When discussing battery types they said AGM-1 is used for Lifeline batteries and AGM-2 for “most other brands”. That’s not something you can go on 100% but it’s worth noting.

That's pretty much what the chart I posted says in the text above the chart. 

[Steve P]

Well, I switched my setting today from Flooded to AGM2.  The charger stayed in float charging mode at 13.8-14.0 volts.  I don't boondock hardly ever, so getting another few percent of charge may not be noticed... but hopefully the batteries will last longer (like several years) .