Solar Float Charge

egarant wrote:
Question is, what should be my cut off voltage charge setting in my solar controller?.... I have it currently set at 14.2 volts

Hi Mr. E
14.2V is too low for bulk/absorption charging and too high for float.
For best performance and long service life, those DieHard Platinums (EnerSys/Odyssey AGM's) should be charged like this:


Cheers,
Mark

smooth1 wrote:
I just upgraded with 2 of those Grp31 Diehard AGM batteries in my Lance 830 which has a PD9245 converter/charger. The PD9245 has a 14.4, 13.6, 13.2 3-stage charge profile. My camper is always plugged in letting the charger maintain the batteries. Let me know what you find out about charging these batteries.

I also have a Progressive Dynamics, model PD4045 which has a 45 amp charger. Boost mode of 14.4 volts to 90%, then Normal Mode of 13.6 to 100%, then 13.2 volts Maintenance Charge.
Equalization takes place every 21 hours for 15 minutes at 14.4 volts.

My PWM Solar Panel Charge Controller has currently has 280 watts of panels hooked to it providing a max of 16 amps to the Solar Controller which I currently have set at a 14.2 cut off charge. When the batteries drop below 14.2 the Controller will begin charging the batteries again.

I did notice that in the solar panel manual under Selecting the Correct Battery it states: "you may choose a Sealed Lead Acid battery, a Gel-Cell or a Deep Cycle 12 volt battery."
No mention of AGM's.........hmmmmmm

I just upgraded with 2 of those Grp31 Diehard AGM batteries in my Lance 830 which has a PD9245 converter/charger. The PD9245 has a 14.4, 13.6, 13.2 3-stage charge profile. My camper is always plugged in letting the charger maintain the batteries. Let me know what you find out about charging these batteries.

egarant wrote:
I have two DieHard Platinum Marine Group 31 AGM batteries.
Question is, what should be my cut off voltage charge setting in my solar controller?

From what I have gleaned off the Internet, I have it currently set at 14.2 volts.

Sound good?

Mr. E

Sears Platinum batteries are mfgrd by Enersys which also is sold under the Oddyssey brand name.

Here is the Odyssey Technical Manual.

Start reading at page 15.

Ask more questions. :)

HTH;
John

Here is some good info on AGM's by one of the better manufacturers:

Batt info

See page 19 of the manual, charge voltage for the three modes is affected by the battery temperature.

Simplygib wrote:
I looked around a bit but can only find hearsay in forums and such. One fellow said Sears told him absorption set point should be 14.7v, float at 13.6v. Several people said Sears Platinum AGMs are rebranded Odysseys, so Odyssey specs apply. That post is here. But as I said, all hearsay. I would see if Sears has any official printed material, or Odyssey if it can be confirmed that these are in fact rebranded Odysseys.

The Sears site has no info at all on what any charge voltages are. I think that is crazy given the cost of these batteries. I have also heard that these are Odyssey batteries as we'll, thanks, I will check that post.

Hi smk,

Since the source of charging is solar--it is not "weeks on end".

I'd contact the battery maker myself. Beer budget so I could not afford to waste a set.

I have never seen an AGM float spec above 13.8 volts.
14.2 all day while in use is probably fine but would seem a bit high to me for storage for weeks on end.

I looked around a bit but can only find hearsay in forums and such. One fellow said Sears told him absorption set point should be 14.7v, float at 13.6v. Several people said Sears Platinum AGMs are rebranded Odysseys, so Odyssey specs apply. That post is here. But as I said, all hearsay. I would see if Sears has any official printed material, or Odyssey if it can be confirmed that these are in fact rebranded Odysseys.

smkettner wrote:
14.2 is fine.... but for how long until it drops to float?

14.2 is the float voltage. That's about the same as an alternator steady state voltage. Works great with my AGM batteries.
(but as stated above, some batteries have different specs for float voltage)