?guidelines for batttery parameter settings?

Started by Barry Fields, May 20, 2023, 02:49:57 PM

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Barry Fields

Would it be beneficial to develop a "one stop" post to explain settings for the many battery chemistries. There is much good information spread out amongst multiple posts and links that might be consolidated in one place.
I would think it would advise as to where to start with Absorb & float settings and how to know if your peculiar settings are working as expected.
I know there is a lot of knowledge out there in this community that could be tapped. Me thinks that Vic is a veritable storehouse of useful information.

If I have missed any thing, let me know.

Regards
Barry
20 years experience in Field Service and Engineering Support in life support equipment and the computer Industry.
I pride myself in diagnostic skills and NOT knowing everything. I do know how to ask the right questions of those who should know the answers. I can do this politely.

Barry Fields

So much to consider. Feed back would be appreciated.

First, Deka has changed it's energy charging specs as of 11/22. I have attached both here for your perusal.
20 years experience in Field Service and Engineering Support in life support equipment and the computer Industry.
I pride myself in diagnostic skills and NOT knowing everything. I do know how to ask the right questions of those who should know the answers. I can do this politely.

Barry Fields

More to ponder. This is a copy of the email sent to EastPenn Deka and their response. I have attached a float current graph that I found. I am not claiming the graph is gospel but it could be useful.Float-Current-Vs-Temperature-at-constant-float-charging-voltage-of-23-VDC-cell.png

Hi Barry,

 

See my answers below in purple:

 

1] The ABSORB and FLOAT voltages are expressed as a range. If one were to start mid-range, what circumstances would indicate whether to raise or lower those setpoints? (specific gravity readings are only available for flooded batteries).

                Answer: Please note that you probably have an old charging parameters. Please use the attached instead, where the range was eliminated.

 

2] Could FLOAT current be used as an indicator of a properly set ABSORB cycle?

                Answer: I am not sure I understand your question. Please set your charger according to your system voltage. For example, if you have a GEL 48V system, the float "voltage" would be set as 54V. Use the same concept for AGM or use 3rd column for flooded monobloc battery.

 

3] Is the attached graph at all useful in determining what that FLOAT current should be?

                Answer: I don't recognize the attached graph, that said, the maximum current allowed for a monobloc battery is 30% of C20 rate.

 

4] I am under the impression that electrolyte stratification takes a couple of days to become significant.  Am I correct in saying that the taller the battery, the more stratification could occur?

                Answer: Stratification or sulphation occurs over time due to over-charging or under-charging the system. It can also occur when battery spend an extended period of time in idle. How long it takes it depends on the battery (Gel/AGM/Flooded) and the system itself. Two days is a short time for a cell to sulphate. That said, if the system is designed properly, it should not occur.

 

5] Solar systems might start BULK charging in the morning @ 1% of C/20 and rise to a maximum mid-day. During that time the charge current could be anywhere in that range due to clouds/overcast). Is there a minimum charge rate/time to prevent/reverse stratification of the electrolyte?

                Answer: The attached charging parameters spells out the time needed for each stage. If a battery is sulphated and you are trying to break the sulphation, you may need to equalize the batteries. Keep in mind that there are cases where the batteries may be sulphated beyond repair.

 

6] Many solar users use "end amps" to determine the end of the absorb cycle. Your specification of a delta current change makes more sense to me, but more difficult to monitor and implement. Is there a compromise here?

                Answer: We created our charging parameters based on voltage and current limit (15% min of C20 rate and 30% max of C20 rate). If you have a programable charge controller with LVD and temperature compensation, you shouldn't have issues with implementation and monitoring. I am not sure if this is what you are asking.

 

I hope I answered your questions, but if not, please do not hesitate to contact our team.

 

Sincerely,

Glauci Rosen

Technical Support Lead | Energy Storage Group

MK Battery – DEKA Solar
20 years experience in Field Service and Engineering Support in life support equipment and the computer Industry.
I pride myself in diagnostic skills and NOT knowing everything. I do know how to ask the right questions of those who should know the answers. I can do this politely.