Guys, I feel your frustration with regards to charging and maintaining the L-16 batteries. First it was to charge the L-16 batteries on AGM1, then it was AGM2, and now back to AGM1. Will this nonsense ever end? I tried back in June to open a line of communication and open exchange of thoughts/ideas on charging/maintaining ALL Discover AGM batteries with Entegra but unfortunately it fell on deaf ears.
First, Discover batteries recommends charging the L-16's AND
the smaller EVGC6A-B batteries at an Absorb voltage of 14.7v and a Float voltage of 13.6v.
For model years prior to 2017 the Magnum inverter panels came set to and Entegra recommended AGM2. Why then for batteries that are recommended by Discover to be charged the same (L-16's and EVGC6A-B) is Entegra recommending that the L-16's be charged on AGM1? It is all for the sake of Equalizing. The AGM1 setting was designed exclusively for Concord Lifeline batteries, not for other brands of AGM batteries. So for Vegatouch owners on AGM1 you are under charging your batteries for the entire month and then overcharging your batteries when the panel asks for you to Equalize. A sure recipe for disaster. More on this later.
For AGM1 the batteries will charge to an Absorb voltage of 14.3v and Float at 13.1v. In each case it is almost 0.5v under what is recommended by Discover. The Float voltage of 13.1v is only 0.2v above what a fully charged battery at rest is listed at, 12.9v. If a battery is down from 100% SOC do you think a voltage of 0.2v above a fully charged battery will bring it back to 100%? I do not think so. It would be equivalent to trying to bring your front tires from 120 psi up to 125 psi with a 127 psi compressor.
The AGM2 setting is better than the AGM1 setting in terms of charge voltages as compared to what Discover recommends. Absorb charge for AGM2 is 14.5v and Float is 13.5v. For those with a non-Vegatouch equipped coach you can improve on the AGM2 setting by selecting a Custom setup and set exactly what Discover recommends, Absorb 14.7v and Float 13.6v. PM me if you would like a copy of these settings. Unfortunately the Custom settings were never included in the Vegatouch panel.
When a Newmar owner with Discover EVGC6A-B batteries (yes, they use the same batteries as an option in their motorhomes) he went to Magnum and asked for their input. Here is what Magnum had to say.
Magnum Settings for Discover AGM Batteries
I thought I would share this information since many of you are placing orders with the AGM special. There is a lot of information out there regarding how to configure the Magnum ME-RC panel for the different types of batteries. Since I spent the extra money for these batteries, I want to extract all the benefit that they can provide, and you'll never be able to do that with incorrect settings. I decided to go to the source and contacted Magnum directly to see what they would have to say. I received the following response from Darren Massey.
"The Discovery AGM EVGC6A-B batteries are asking for a higher charge voltage than any of our profiles have. Here is where I found that information http://www.harrisbattery.com/sites/d...s/EVGC6A-B.pdf
. Their charge profile are absorb at 14.7 and float at 13.6. So flooded would be the closest absorb at 14.6 and float at 13.4. So I would recommend setting 04 battery type to "custom" and setting the absorb to 14.7 the float to 13.6 and equalize to 14.7 then the 05 charge rate would be 100% and then since you have 828 amp/hours change 03 absorb done time to 2.5 hrs."
For what its worth.....
2017 Newmar Dutch Star 4310
2016 Chevy Suburban LTZ w/ M&G Braking System
The other day I ran an experiment with my batteries set on AGM1. Referencing my battery monitor I first discharged my batteries down to 60% SOC and then to simulate a Vegatouch panel on 30 amp service I switched off the smaller 100 amp battery charger and let the larger 125 amp battery charger do all the work. Here is what I found.
Bulk charge lasted for 1:55 and brought the batteries from 60% up to 78%. Absorb lasted for 2:30 (the Magnum standard for this size of battery bank) and brought the batteries from 78% up to 96%. Once Absorb is finished the batteries go into Float mode for a timed period of 4 hours. The Float time period did nothing to bring the batteries up to a higher state of charge. Once Float was complete the batteries went to Full charge. Full charge is where the charger is turned off waiting for the voltage on that inverter panel to drop to 12.6v prior to resuming another 4 hour Float period. During my experiment the batteries dropped to 88% SOC (which coresponded to 12.6v) and then Float charge resumed for a period of 4 hours at which time the SOC increased from 88% to 91% before the batteries went to Full charge once again. Once again the SOC dropped to 88% prior to Float charge resuming for 4 hours and the batteries this time only came up to 90% SOC. At no time during this experiment did the batteries ever reach 100% SOC. This is what I was referring to earlier, under charge your batteries for the majority of the month and then over charge them by Equalizing them once a month.
One other observation of note during this experiment. I had my solar panels turned off so as not to skew the above results. If your motorhome does not have solar panels installed and you have a Final Charge setting of "Multi" instead of "Float" (located under "SETUP" 09) after the 4 hour Float charge period your inverter(s) will switch to Full charge and you will experience similar results as above and never achieve 100% SOC after the first Float cycle.
After the two year warranty period you will be responsible for replacing these expensive batteries so it would be in your best interest to look after them now.