Progressive Dynamics converter and AGM batteries

DAS26miles wrote:
Any thoughts?

My concern would be that most converters don't offer temperature compensated charging which manufacturers such as East Penn insist must be used with their own brand of DEKA AGM batteries. IIRC the Parallax TempAssure converter is one exception that does offer TC charging.

You need a Trimetric for the ammeter with AGMs Only way to tell if they have completed a recharge fully is to see when the amps taper to 0.5a per 100AH of battery.

That's when you keep the charging voltage at 14.x(whatever the AGM specs say--it is different for different AGMs but you will have 14.4 no matter what with the PD which is close enough) all the way till then, and do not drop to Float 13.6 until then.

So good news, just keep hitting the Charge Wizard to maintain 14.4 every four hours and you can do the voltage part. (Means you have to be around for that, not downtown or wherever)

So all you need is a Trimetric if you don't have one now, and you can go AGM.

AGMs are not lighter than Flooded per AH.

AGMs do not weigh less
mine are heavier than the FLA they replaced

yes those 6 pack orbital wound Optima batteries weigh less, because they have less lead and LESS AmpHrs of capacity

Normal AGMs weigh just as much as their FLA counterparts
normal grp 27 AGM will weigh as much as your FLA grp27

i still like and use the AGM
no venting, faster recharge, no checking fluid level, no corroded wiring

What brand AGM's are you all using? I'd like 100ah if possible.

PD and Lifeline charging specs are an exact match.

I have had two of these for a couple years now (except mine are branded as "Stark") They are pretty good for RV deep cycling work.

Their charging spec is 14.5 to 14.9 so 14.4 will be "close enough"

http://www.bestconverter.com/UB121000-100-AH-Deep-Cycle-_p_293.html#.XAR6i1KWxLM

Checking with PD intelli-power and says it works with AGM's. Looking at Duracell Utra Platinum Group 27 AGM's. $220 each less 10% ordering online and picking up. Not too bad. Just the 92ah I don't care for. I was hoping for 100ah but if it recharges 5 times faster, it shouldn't make a difference. I was using my generator for and hour in the morning and 2 hours in the evening and still down 10 accumulating amps per day. Solar only kept it from dropping any further in daytime. But by third day I was down 30 amps on the third evening after charging. I'm hoping that the AGM's will get it charged back closer to full. I know part of the issue is the PD Intelli converter chgarger claiming to get the batteries up to 90% within 2-3 hours and another 15 hours to fully charge.

I’d go with Renogy 104AH 12V AGM batteries.....Group 31 size. Available on Amazon for $199. and free shipping for Prime members. I am extremely pleased with mine.

Renogy AGM battery on Amazon

I don't understand where all this talk of AGMs charging faster comes from. My AGMs charge the same speed as my previous Flooded ones did. IMO this is a bogus claim from measurements doing both.

It is true you can use way higher charging rates with Lifelines, but not with most of the other brands. My AGMs spec is to limit them to 27 amps per 100 AH, so a 55 amper on a pair comes out just right.

You can't speed up your charger doing its max rating.

Another story is you can get a better time to full charge because the AGM stays in Bulk longer so Absorption is shorter. Not with my AGMs.
And even if true (doubt it) who cares? You don't go to full on generator time so no time saving while camping. If on shore power who cares if you save a little time--time does not usually matter on shore power.

Mex says AGMs need to be recharged at a 20% or better charging rate during the Bulk stage. So that means on a bank of 200AH, you need at least 40 amps and not more than 54 (two 27s) I use my 55 amp for that.

From Battery University:

AGM has very low internal resistance, is capable to deliver high currents on demand and offers a relatively long service life, even when deep cycled. AGM is maintenance free, provides good electrical reliability and is lighter than the flooded lead acid type. While regular lead acid batteries need a topping charge every six months to prevent the buildup of sulfation, AGM batteries are less prone to sulfation and can sit in storage for longer before a charge becomes necessary. The battery stands up well to low temperatures and has a low self-discharge.

The leading advantages of AGM are a charge that is up to five times faster than the flooded version, and the ability to deep cycle. AGM offers a depth-of-discharge of 80 percent; the flooded, on the other hand, is specified at 50 percent DoD to attain the same cycle life. The negatives are slightly lower specific energy and higher manufacturing costs than the flooded, but cheaper than the gel battery.