EPDM Coatings
rvupgradestore.com Composet Products Custom Yacht Interiors

Author Topic: Solar controller, Prog Dynamic PD4645, and AGM battery question  (Read 286 times)

TravMan

  • ---
  • Posts: 11
Iím upgrading a battery in my camper van from a 75ahr flooded battery to a 84ahr AGM which was gifted to me. Here is the configuration it will be going into;

Progressive Dynamics PD4645 converter/charger (upgraded from original Magnatek 6300?).
Renogy 100w panels x2 w/ Rover 20amp MPPT controller
Charging also via auto alternator
AGM 84ahr battery

I can customize the solar panel controller to use any voltage between 9-17v for the various charge cycles (see chart attached).

Can anyone provide an further details or suggestions on how I should program the Rover MPPT controller to work well with the PD4656 and vehicle alternator charging? Should I match the parameters to the PD4645? Change the PD4656? Use one or the other? Not sure what is the best route to take on this. Any help would be greatly appreciated.

Also, my understanding is that with flooded cells, you should not use more than 50% of its capacity for long life. With AGM, the word seems to be not more than 80%.  Is this correct?

First attachment is the Renogy Rover 20amp MTTP solar controller
Second and third are from the BestConverters.com website for the PD4645 converter/charger


Gary RV_Wizard

  • Forum Staff
  • ---
  • *
  • Posts: 61026
  • RVer Emeritus
Re: Solar controller, Prog Dynamic PD4645, and AGM battery question
« Reply #1 on: June 18, 2017, 11:12:15 AM »
Optimizing it may be a matter of much debate, but starting with the 4645's parameters is a solid place to begin.  The ideal parameters for the AGM battery vary by battery manufacturer, if you can identify who that is. Most batteries are private label brands with little spec info available, so figuring out what the manufacturer recommends can be difficult. If you can figure out who actually made the battery, you can use that manufacturer's house brand as a model and be 99% sure you have it right. However, in actual use there are many things that affect battery life besides the charge profile, so it may not be worthwhile to agonize much about optimal vs generic AGM charging parameters.

Does the 4645 have an AGM setting, or does it treat all batteries the same?   
« Last Edit: June 18, 2017, 11:14:15 AM by Gary RV_Wizard »
Gary
--------------
Gary Brinck
Summers: Black Mountain, NC
Home: Ocala National Forest, FL

TravMan

  • ---
  • Posts: 11
Re: Solar controller, Prog Dynamic PD4645, and AGM battery question
« Reply #2 on: June 18, 2017, 11:30:46 AM »
Optimizing it may be a matter of much debate, but starting with the 4645's parameters is a solid place to begin.  The ideal parameters for the AGM battery vary by battery manufacturer, if you can identify who that is. Most batteries are private label brands with little spec info available, so figuring out what the manufacturer recommends can be difficult. If you can figure out who actually made the battery, you can use that manufacturer's house brand as a model and be 99% sure you have it right. However, in actual use there are many things that affect battery life besides the charge profile, so it may not be worthwhile to agonize much about optimal vs generic AGM charging parameters.

Does the 4645 have an AGM setting, or does it treat all batteries the same?

I'm not really worried about optimization per se, but making sure the PD4645 and solar controller are not fighting and damaging the battery. Also, the PD4645 has an equalization mode which I understand is not recommend for AGM batteries. The PD4645 does not have a specific AGM voltage profile, nor is there any way I can change the voltages based on what the manual states.

The PD4645 it set for a 14.4 boost mode, 13.6 normal, 13.2 storage, and a desulfation mode of 14.4 every 21 hours for 15 minutes.

The solar controller is set for a 14.2 boost, 13.8 float, 13.2 boost return, and no equalization.

I'm not sure if these settings will work together well, or may be damaging the battery over the long term, as I don't understand how the two charge controllers will react to the different voltages. It may be fine, or I could be damaging the battery. I just don't know and trying to understand.
« Last Edit: June 18, 2017, 11:32:42 AM by TravMan »

Kevin Means

  • Forum Staff
  • ---
  • *
  • Posts: 3818
    • Tactical Flying
Re: Solar controller, Prog Dynamic PD4645, and AGM battery question
« Reply #3 on: June 23, 2017, 01:01:53 PM »
All solar controllers that I'm familiar with can detect when the batteries are being charged by another source, and they'll throttle themselves back to prevent overcharging. There may be some cheap brands that don't but I'm not aware of them.

Those voltage parameters you mentioned should work for an AGM battery, and I doubt you'll notice any short term problems. AGMs, however, do have a slightly different charge profile than "standard" lead/acid batteries, so they may (over time) not live as long as they might have lived had they been charged with AGM settings.

Kev
2011 Winnebago Tour 42QD
Towing a Jeep Rubicon Unlimited LJ or an Acura MDX
RVI Brake 2, Minder TM-66 TPMS, 970 watts of solar
(Can't wait to spend more time RVing)
Lakeside, California

Gary RV_Wizard

  • Forum Staff
  • ---
  • *
  • Posts: 61026
  • RVer Emeritus
Re: Solar controller, Prog Dynamic PD4645, and AGM battery question
« Reply #4 on: June 24, 2017, 09:57:18 AM »
With a super-technical thing like this, it's too easy to get bogged down in the details and miss the big picture. Each charge source (controller) sees what it views as a "battery" at the end of its output wires. That "battery" has a voltage and accepts some level of charging current (amps). Each controller looks at the volts and amps and responds per its own preset parameters. If another source is charging the same battery, the voltage is up and the battery appears to be already charged, so any smart controller throttles back. This happens continuously and stays in balance.

The only bad situation is when one of the charge sources is NOT a smart controller and just tries to force amps into the battery. These chargers will overcharge on a regular basis anyway, but the problem is exacerbated when another charger is active. Fortunately, both the PD and the Renology are "smart". The old Magnetek was dumb as a rock!
Gary
--------------
Gary Brinck
Summers: Black Mountain, NC
Home: Ocala National Forest, FL

AStravelers

  • ---
  • Posts: 693
  • Part time travelers, 4-8 months each year.
Re: Solar controller, Prog Dynamic PD4645, and AGM battery question
« Reply #5 on: June 25, 2017, 11:53:20 AM »
Regarding DOD figures.

The numbers I have seen for figuring the life of the batteries depends on how far you discharge them.   While I have "heard" that AGM will tolerate a deeper discharge than flooded cell I have not seen numbers from a mfg like Trojan supporting that.   To me the longer life of an AGM at discharge of 80% would be significant if it provided 30-50% longer life than a flooded cell being discharged to 80%.  If it is only 10-15% I would consider that insignificant.

Anyways the approximate numbers:
--  discharge 25% (75% full)  and you will get 2000-2500, maybe 3000 cycles
--  Discharge 50% and you will get around 1000-1200 cycles
--  Discharge 80% and you are down to 500 cycles. 

Bottom line, discharge to 25% for long life.  Loose 50% of the life at 50% and loose 75% of life at 80%

So it really depends on how much you use your batteries.  Personally we dry camp/boondock 60% to 80% of the time.  At 6-10 months of the year on the road that is a lot of cycles in a year.  If you only dry camp 40 days a year, it probably doesn't matter that much if you discharge to 80%. 

Al & Sharon
2006 Winnebago Sightseer 29R
2009 Chevy Colorado 4X4

http://downtheroadaroundthebend.blogspot.com/

 

Hosted by Over The Network