Correct temperature compensation for these batteries?

[off.the.grid]

I'm trying to work out what the correct value is for these batteries. I'm installing 2 of them in my friends RV in 24V configuration.
The epever controller has a default of -3mv/c

Looking at the charge voltages specified, it's a bit lower than most AGM batteries I've worked with.
The dealer claims they can be discharged down to 20% which I don't buy, but would be a breakthrough for lead acid batteries if that was the case.

They are amptech at12750d I think these are made by exide.

Datasheet is here below, it has a table of charge voltages at different temperatures, but have no idea how to translate that into mV per cell.

https://www.supercharge.com.au/wp-content/uploads/2019/10/AMP-Tech-Deep-Cycle-Batteries-6pp-A4-Brochure2.pdf&ved=2ahUKEwixgIed_9n7AhXy8zgGHa5hAGAQFnoECBQQAQ&usg=AOvVaw2c83qu390DcTLPPvB-cPTn

 

[RCinFLA]

AGM's are lead-acid and have similar temp comp on charging. AGM typically have a slightly higher acid concentration giving them a slightly higher cell voltage.

AGM's also typically do not have a support grid like flooded cells. Their plates are pure lead supported by compression between AGM separators. This gives them local lead plate support so they do not suffer pasted lead onto grid support attachment issues. This allows a deeper discharge without structural failure between pasted lead and support grid.

AGM's are electrolyte starved meaning they cannot afford water loss in the limited electrolyte so must be careful of overcharging. You cannot replace lost water that will get vented if too much overcharging is applied. Never equalize charge an AGM.

Since the lead plates are tightly bound against AGM matts, any hard sulfation due to lack of charging for some time is impossible to remove from plate surface so it is even more important to keep them fully charge. On the positive side, they have less self discharge than regular flooded cells, especially compared to antimony alloy grid deep discharge flooded cells.

 

[Prince Of Darkness]

Hi o.t.g ...

The link that you show, above, is broken, to me.

The following link shows that this batt is a 75 Ah 12V Motorcycle batttery:

AT12750D - AMP-Tech Amptech Valve Regulated Lead Acid Adventure

AT12750D AMP-Tech Amptech Valve Regulated Lead Acid Adventure

www.supercharge.com.au

Maybe this is not the subject battery. FWIW, 'Luke'

 

[off.the.grid]

Hi o.t.g ...

The link that you show, above, is broken, to me.

The following link shows that this batt is a 75 Ah 12V Motorcycle batttery:

AT12750D - AMP-Tech Amptech Valve Regulated Lead Acid Adventure

AT12750D AMP-Tech Amptech Valve Regulated Lead Acid Adventure

www.supercharge.com.au

Maybe this is not the subject battery. FWIW, 'Luke'

These are 120AH 12V batteries, sorry it looks like the datasheet provided to me had showed a different model number, but same series.
Here is the model number:
AT121000DS

 

[off.the.grid]

Anyone able to tell me if -3mv per cell will do sny harm?
Thanks

 

[Prince Of Darkness]

Anyone able to tell me if -3mv per cell will do sny harm?
Thanks

YES, that was your question.

-3 mV/C has become more common, in the past 5 or more years.

Would contact the battery manufacturer, or the battery dealer, for guidance. Sometimes the exact value can depend upon the type of service (Standby, or Cyclic use).

Using the correct value for the exact batteires and service can be very important, especially for applications that deal with temperature extremes, IMO.

Luke

 

[off.the.grid]

YES, that was your question.

-3 mV/C has become more common, in the past 5 or more years.

Would contact the battery manufacturer, or the battery dealer, for guidance. Sometimes the exact value can depend upon the type of service (Standby, or Cyclic use).

Using the correct value for the exact batteires and service can be very important, especially for applications that deal with temperature extremes, IMO.

Luke

Ok, well I will see if I can find any more information from the supplier, the shop only provided me the datasheet you see here.