Changing to AGM using Magnum 2812 & ME-RC & BMK
I am trying to help dear friends who are now on the road for a 6-week trip.
Two weeks ago, I removed his (4) L-16's which had suffered a catastrophic low-water situation and were destroyed. There was a well-known watering system installed and the owner was fastidious about pumping the bulb and supposedly filling the batteries every month. Each battery was all but completely dry and one had ruptured its case. L-16's were installed approx five years ago after our trip with them to Alaska, and it seems the watering system might NEVER have worked. The batteries are in a 2011 Camelot where they are TOTALLY inacessible to inspect water level, so the watering system was chosen.
His BMK had stopped functioning some months before, and if it was not indicating 0% SOC, it would display "Think'n". Likely related to the fact that the L-16 batteries were being tortured to death from lack of water.
Replaced the house batteries with (4) Lifeline GPL-6CT AGM batteries. Less AH, but entirely adequate for his use. Checked and refreshed all connections. Replaced the BMK sending unit (near the shunt) because it had an internal component melted. Related?--Unrelated?--I don't know. At least with the lower-height Lifelines, it is possible to physically inspect the water level in the batteries. Did NOT reinstall the watering system.
Also replaced the chassis batteries with two Group 31 maintenance-free Lead-Acid (Not AGM) batteries. No reason to replace the chassis batteries other than to insure a trip with no ugly surprises.
With everything reconnected, electrical function in the coach was restored... from the inverter, the batteries themselves, and from shore power. I changed the settings on the ME-RC from lead-acid batteries to "AGM 1". YES, I'm fully aware that we have a mixture of LA and AGM batteries here, but the charging parameters, as listed on the Magnum and LifeLine sites, are not significantly different...AT LEAST as far as I can see. We disconnected the data cable from the MBK to allow it to "reset".
Fast-Forward to the PRESENT problem. The Magnum 2812 is charging all the batteries. The BIRD appears to be working properly, although I'm no expert on that system and prefer the simplicity of the Blue Sea ML-ACR. PRESENT PROBLEM (if indeed it IS a problem) is that the BMK continues to show "0% SOC" and the charger section of the ME-RC/Magnum 2812 goes through the three-stage BULK-ABSORB-FLOAT sequence, then the ME-RC displays "Fully charged" and the charger section TURNS OFF and goes into "Standby". It will not return to "Charging" ("Charging" LED "ON") until the ME-RC shows battery voltage has declined to 12.2 VDC. That seems too low, does it not?
"Standby" might be OK if the ME-RC was deciding that AGM batteries needed no continual "float" charge and would cut itself off, waiting for battery voltage to fall to some value at which it would turn the Charging section "on" again and restore to the "totally charged" level. But should that not be something near 12.5 VDC or higher?
I have only been able to assure my good friends that if they are vigilant in seeing that the "CHARGE" LED on their ME-RC is "ON" when they see a battery voltage below 12.5 VDC, they will not have any battery-related problems until they are home and I can look into the problem further.
My contact with Magnum Tech Support was answered by a well-meaning fellow who seemed to be surfing the database of his Magnum employer, but seemed totally clueless, except to read to me from the ME-RC manual. I've done that myself, and there are MULTIPLE references to explain the operation of the Magnum 2812, but virtually nothing UNAMBIGUOUS about this particular problem. As always, the line between the "professional" technician and the "amateur" technician often has nothing to do with their employment status.
My friends are good Christian people who have limited technical expertise and know only to pray when things go wrong. I hope you will help me help them. Myron (YC1) and "Twinboat" might be the two most knowledgeable folks on this subject. Myron, I'm sure you remember Tom & Paula, and I hope you want to help. Twinboat, you are an extremely knowledgeable contributor...I hope you are willing to help if you can.
I apologize for the length of this post, but when I am trying to help someone with a problem, so many folks seem to miss explaining fully and completely what the problem is, and what coach it applies to.
I hope you are able to help me help my good friends.
The me-rc will not use the the shut to determine if the battery’s need to be charged a me-arc is required.
So that eliminates the shut for the charging parameters.
Since you used the agm1 charging profile my guess is that it is pre configured for the 12.2 recharge voltage.
Did you set the magnum shut for the new amp hours for the new battery set?
On Magnum inverter/chargers, AGM1 is for Lifeline AGM batteries. AGM2 is for East Penn, Deka, Trojan and Discover AGM batteries. The source for this is the manual for the Magnum remote panel, ME-RC.
I need to verify with my friends that they are not touching any ME-RC buttons once the ME-RC reports "Fully Charged."
Thanks for your reply.
On mine I had installed all Lifeline AGM batteries 10 of them 8 house two chassis. When I was at Elite RV in Harrisburg, OR having some work done, Erik noticed on my control panel for the Magnum that I had it set on AGM 1 and he switched it to #2. Said something about it being a better or higher charging profile for having all AGM batteries. The house batteries are 7 years old now and still working good, just had to replace the starter batteries because one of them was failing at 7 years old. Randy
I have an ME-RC and there is a setting for 'final charge' . It can be set to 'Full Charge' or 'Float Charge'. It appears the unit you are working on is set for final to be 'Full Charge'. That removes the trickle or float charge until a bottom threshold voltage is reached. Get a remote manual. It will help you more than someone on a phone. Once you learn the remote setting procedure, it is really pretty easy... plus you can set up custom settings with that remote.
Typically 12.4v is the point to resume charging.
Lifeline tech support would likely be a good source of help.
Should AGM batteries NOT have permanent Float Charge?
Does anyone have a definitive, clear, unambiguous answer to this question? I am suspecting that the "AGM 1" cycle causes Float Charging on the Magnum ME-RC to last only a standard time before interrupting charging completely...until battery voltage falls to some preset point.
Maybe the charge profile is normal.
Since you have installed Life Line batteries you should look up the specifications for them specifically. Life Line AGM batteries tend to be a little out of the ordinary.
In general voltage for long term storage of lead acid batteries should be a constant 13.2 volts.
For disconnected storage, fully recharge before voltage drops to 12.4 volts. A full charge means 10 to 14 hours of charging. I would not expect to see 14.4 volts for more than a few minuets if you start at 12.4 volts or higher. 13.6 charging volts would be normal.
Lead acid batteries can't absorb the extra current unless they are deeply discharged. Phigh State ofushing the voltage up for longer periods when at a Charge only produces hydrogen gas and grid corrosion.
I don't fully understand your description of the behavior. But it may be normal. Iordt depends on the charging voltages that go with the ws you are using.
If "Float" is 13.6, then that is the correct voltage for charge during recharging while disconnected. The ideal would be to disconnect until voltage drops to 12.4 then use 13.6 for 10 hours to bring them back to full.
It matters weather you are charging the batteries during storage using shore power, solar power, or generator. With the generator, you don't want to run the generator constantly to produce 13.2 volts at extremely low currents.
Disconnecting until voltage drops to 12.4 volts then auto starting the generator for a while makes sense. Batteries may stay above 12.4 volts for a week or two before needing to start the generator and recharge for 10 hours.
Some people prefer not to run the generator so long for such a small amount of power. They run it for 2 or 4 hours. This works, but the voltage drops to 12.4 sooner and ends up running the generator more often. It also allows slightly more sulfation. That would be a trade off with running the generator for a long time at low power consumption.
Charging from shore power using a constant 13.2 volts makes sense. There is no loss to running for low power use.
Charging using solar is similar to shore power. It is only providing 13.2 to 13.6 volts for the sunny hours of the day, but for the most part voltage stays near 13.2 volt for optimum results.
I wish you good luck and happy trails ahead!:)
AGM 1 Bulk/Float = 14.3 v Float = 13.3 v Equalize = 15.5 v
AGM 2 = 14.5 v = 13.5v = 14.5 v
Either AGM 1 or AGM 2 will work it is simply a preference. I would use AGM2.
As far as the 12.2 v issue you were referring to: as stated above it has to do with your Final Charge setting. You appear to have a final charge setting of Silent which turns off the charger until the voltage drops to either 12v or 12.2v. You need to change the Final Charge setting to -Multi which will place it back into the Float range for volts.
I have a similar setup.
I have the Magnum Ms-2012 inverter and the ME-BMK and 4-100ah AGM Deep Cycle batteries. I use the latest remote the ME-ARC50.
My system is set for AGM2 because I don't have Lifeline batteries (AGM1 is for Lifeline). It will charge my House batteries to Float and after 3-hours at float it turns off charging and starts charging again at 12.6v. I believe this is also changeable in the ME-ARC50. You can change it to not shut off, or to shut off quicker, or stay shut off longer and restart at a lower voltage.
Odd you had a poor tech experience at Magnum. I've always had great help and via email to their support they sent me a custom list of the proper settings for my batteries.
Newmar forum member Redbarron created this booklet to help you understand the settings options and how to figure out what to use:
Here is my setup chart as provided to me from Magnum and it commonly seen as a usual AGM setup:
01D-max charge: 200ADC
02A-search watts: 5 watts
02B-LBCO : 10.7 VDC
02D-AC in: 11.0-14.1 VDC
02E-AC in SOC: 80% to 100% (this can be safely lowered to 50% for boon docking)
02F-Power Up:Always On
03A-AC Input: Amps=30A (or 50A)
03B-VAC Dropout 100VAC
03C-Battery Type: AGM2 (Lifeline is AGM1)
03D-Absorb Done:100% SOC
03E-Max Charge Rate: 100%
03F-Max Charge Time: 18.0 HRS
03G-Final Charge Stage: Multi
03G-EQ reminder: off
05A Charge Eff: off
05B Amp Hour Size: 400ah (or whatever you have)
As to the BMK be sure the data cable is plugged into the network port on the Inverter. If you have a PCS Powerline Power Center there maybe two data cables needed for the one Network port. Or if you have a Magnum AGS (Auto Gen Start) you may need a three way splitter.
It's a simple land line phone RJ11 splitter, but I had trouble with the first two I tried. I'm not sure what the problem was. I found one that said it worked with the Magnum and it did. However, I can't find the info on that specific splitter I used.
I am by far not an expert but if I understand your post correctly you have a problem with the BMK never showing a SOC. It seems the batteries are charging thru the three stage charger correctly. I am going to take a wild guess and say that the problem is to do with the shunt for the BMK. It is recommended to install that shunt in the negative (to ground) lead of the house battery bank and I expect that is where you installed it. There will be a twisted pair from the shunt back to the BMK module that measures the voltage drop across the shunt. I know you understand how that works and I=ER and that you are dealing with a very low voltage on that twisted pair back to the BMK module. When Tom and Paul get back to your place I would carefully check that twisted pair and the connections. I do happen to have a brand new BMK module that you are welcome to if you need it. Do not know Tom and Paul's schedule but we are leaving home in a week and will be gone for six weeks.
You would think there would be some sort of RESET for the BMK's SOC, but the manual says if power is interrupted to the BMK module (the one connected to the shunt) it will display "Think'n", which it did in the beginning. The manual only says that the BMK will calculate its "100%" point on its own, based on when it sees the voltage stabilized over a long period, indicating full charge.
If it's not too much trouble, could you send me the following info accessed from the TECH 02 menu of YOUR ME-RC--the revision level of 1) your inverter, 2) your remote, 3) your BMK. And also from TECH 03--your inverter model. And one last thing--the P/N of your ME-RC MANUAL. Mine is 64-0003 Rev G. The front cover of my ME-RC manual reads: (Revision 2.8 or higher: includes AGS & BMK info.
And if it's convenient for you, ship me the BMK module before you leave on your trip. I'll reimburse you for shipping, and if that is not the problem, I'll ship it back to you.
I think I have the charging oddities figured out and can fix them when I have access to Tom's ME-RC. But I'm not sure what is going on with the BMK. Tom has advanced his understanding of mechanical/electrical things by a quantum leap, but it is difficult to troubleshoot these things with him over the phone.
You can reply to my email.
Thanks, Bob! You have always been ready to help folks.
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