Yes of course, a converter can charge AGM batteries. However, the same Lifeline webpage that Jim linked to provides specific information about temperature compensation and equalizing. I am not familiar with any RV "converter" that offers these capabilities, though I'm eager to learn about such a device should it exist.
Lifeline Batteries Inc. wrote:
1. Use midpoint values for most applications. Lower voltages may be suitable for light-duty applications and higher voltages may be suitable for heavy duty applications.
2. For 24 Volt Systems, multiply 12 Volt setting by 2.
3. Charge voltage should be adjusted if battery temperature varies by more than 10°F from 77°F. Consult website for further guidance (www.lifelinebatteries.com).
Conditioning/Equalizing Charge: 15.5 volts for 8 hours
Conditioning/equalizing should only be done when the battery is showing symptoms of capacity loss. If conditioning/equalizing is necessary, first go through the normal charge cycle. Once the battery is as fully charged as possible, start the conditioning/equalizing charge.
For maximum battery life, a battery must be recharged to 100% capacity. Recharging to less than 100% may result in premature battery failure. Lifeline batteries are not covered under warranty if they are not recharged properly. For more information, please refer to our warranty policy.
This is the best one is really concerned with temp compensation and all the other features if one is really concerned...
Can't equalize AGM's with those (well I suppose you could switch it to flooded mode). Also, charge voltage is only 14.2.
Again I have not experienced or friends/rv.net'ers had a need to equalize their AGM's. No capacity loss...Have read that some Boat folks have had some problems...
Lifeline says that conditioning/equalize should only be used if the battery has been in a low state of charge for an extended period of time and shows signs of capacity loss.
Pg 20 of the manual: http://www.lifelinebatteries.com/manual.pdf
My Iota with IQ4 went into boost mode at 14.8v and a full 40 amps this past weekend. Stayed there for almost exactly 30 minutes before it dropped to 14.3. This was on a Trojan grp27 true deep cycle battery that I put in my fiver for the winter. After 2-1/2 hrs. it was only putting out about 3amps when I pulled the plug and came home.
2009 Jayco Eagle Superlite 25.5RKS
2008 Silverado 2500HD Z71 4x4 Duramax/Allison
Reese 15K slider
270 watts of Kyocera solar
Blue Sky 3024i MPPT controller
450 AHs of Trojan power
Iota DLS-75/IQ4 converter
Again, I can only go by experience... I have not heard of anyone experiencing premature failure of an AGM here on RV.net because a proper functioning inexpensive multistage converter was in use.
Of those that I have experience with, none of them were ever equalized...Optima, Lifeline.
Over the 10 years I have had my Progressive Dynamics I have watched my battery temperature when charging in hot weather. If the battery is over about 95 deg I do not allow the converter to go into Bulk mode by using the Pendant/Wizard..So 13.6vdc is what the battery gets. That works for me and a few others that are concerned about temperature and batteries. I also use the Wizard/Pendant to force bulk mode when my battery (s) are cold...It is the only converter you can do this with.
If you have the funds and need a quick charge, you can't go wrong with replacing the converter with a PD or IOTA.
13.68V is very typical of the 6300 series when operating to spec. It has probably been doing this all along and shouldn't be harmful to the batteries unless it's really hot out. So if you're noticing something different now, a battery or 2 may be the culprit here in the way of a bad cell(s.)
The watering may be due to recent hot weather if you've had that. If you've only had the rig since last fall, then this could be the problem and it's your first chance to notice it. But if you've had it for years and are only seeing this now........... batteries.
How long have you had the rig, batteries, converter, etc.?
P.S. A bad cell can do this. You're turning your 12V pair of batteries into a 10V pair... and then pumping them full of 13.68V-worth, i.e. too much. That's akin to 16.42V for a solid 12V battery or pair of 6s (13.68 / 5 working cells = V/cell * 6 cells)
If you remove the charge, what happens to the battery voltage. If there is no draw and it's below 12.5 within 24 hours, you know you got a battery problem. However, in my experience, a battery or battery pair with one bad cell will drop to more like 10.5V within 24 hours.
* This post was
edited 04/25/12 02:34pm by KendallP *
Last December I load tested the two T-105 and checked specific gravity and everything was in the good range. At that time, I put the camper under cover and hooked up the 120v AC to keep the batteries maintained.
I checked it in January and the water was a little low. (I use a Flow-Rite battery filler system) It took 8 oz of distilled water in Jan. I got hurt on the 3rd of March and have not been able to check the batts until last Saturday. At that time, I put in 24 oz of water on Saturday. I also took a voltage check from the converter and it was 13.8v before I filled them and several hours later it was 13.68v.
Sunday I preformed a load test and both batteries passed well. I allowed them to recharge for 6 hours and then removed the surface charge and took the hydrometer reading. All showed well in the green (I don't have the numbers handy).
So I believe that the batteries are in good shape. I would like to get a better converter so that next year I can change to AGM batteries and not have to change the converter again. I also need to replace some roof vents that are brittle from the sun and I still have some issues with my K-3500 brake lines that need to be addressed before I reload the camper. Got to watch the bank account.
I'll start by replacing the two T-105's with two Lifeline GPL-6CT (300AH). I have 15" of height in the battery cabinet for the taller batteries.
Then within another year I would like to add in the solar. I have plenty of real estate on the roof for 500 watts of cells. After I add in the solar, I intent on adding 4 more GPL-6CT batteries in the bed just forward of the wheel wells.
I am trying to get this ready for living in full time while I build my 2nd home in the sun belt, which has no utilities at the present time.
This is going to be an expensive year before I get on the road.
Thanx again for the help.
Combat Vietnam VeteranSupport our troops for serving our great country.
1997 Veri Lite RL1200 on a '02, K3500, CC, DRW, 8.1L, Allison, 4.1 gears, Bridgestone 225/70R19.5 tires.