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rd10153 avatar image
rd10153 asked

Double-Checking MPPT Settings for Flooded Lead Acid

I added a solar setup to my teardrop. Would someone be so kind as to double-check my MPPT settings?


I'm running a pair of 6v Duracell GC2 flooded lead acid golf cart batteries in series at 12v. They are 215 amp hours each, so 215 amp hours total at 12v. I can't find specs for this exact battery but have read they are the same as the Deka GC10 with specs here.


Editing to add links again as I'm not seeing them above when I view the post.

Duracell GC2: https://www.samsclub.com/p/duracell-golf-car-battery-group-size-gc2/prod3590228

Deka GC10 Specs:


Batt Voltage: 12v

Max Charge Current: 15A

Absorption Voltage: 14.7

Float Voltage: 14.1

Equalization Voltage: 15.3

Auto Equalization: Enabled, Every 45 Days (I've read every 1-3 months for flooded)

Temp Compensation: -18v/C (because I have 6 cells, right?)

Low Temp Cuttoff: Disabled



One other noob question that I think I know the answer to: If the MPPT is sending current to the batteries and I connect to shore power, it will detect the voltage from the power center and regulate current from the solar panel, correct? I'm running a basic WFCO power center.


Thanks!



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JohnC avatar image
JohnC answered ·

Hi @rd10153

GC2's are generic floodeds. All major makers have them, so do I (different brand).

I use 48V but equiv Abs 14.4V. Float 13.6V, TC -20mV/C. I don't Equalize them, they get daily cycled down to ~75% SOC, and I don't think they need it then. They don't need to be pushed hard, gentle does it, they just boil water and get hot if you do.

I don't know this WFCO device, but 2 charge sources always interact via V. Which one takes priority when V reaches the set targets depends on the targets set on each unit. The lower will back off.

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rd10153 avatar image rd10153 commented ·
Thanks for the info! Excess max charge current is what would boil them, correct? Or, excess voltage?


When I'm not camping, it will sit in my driveway for months on end so I'm thinking would be good to have the equalization turned on, though I don't pretend to understand all the chemistry stuff.


I do have a hydrometer so maybe I'll learn a bit more so I can monitor and tweak as I go.


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