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Do I need to futz with my mppt controller?

 
Posts: 70
Location: Binghamton, NY
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I've already told the controller (Tracer 4215BN) the voltage(12), type(flooded), and Ah capacity(225) of the battery bank. However, I saw someone say on another forum that you needed to set the charge voltages for each of the stages manually by setting them all to 12.5V, and use a hydrometer at the end of each day to determine how to tweak those voltages up or down each day, essentially as a daily maintenance task, always chasing optimum charging.  He seemed fairly knowledgeable, but also seemed like a bit of a pretentious prick, possibly taking what is essentially finesse tweaking and basically making it sound like essential death avoidance. But I know jack shit about this stuff, so I figured I'd ask where I know people are more helpful. Can I/Should I just use the factory defaults for charging voltages and trust them to know better than I, or is it something that needs to be customized for each individual situation?

Our setup: We have 4x 100watt 12v panels in series, and two Duracell 6v golf cart batteries, also connected in series for 12v.  I'm intending to get another two batteries and hook them up again in series and then in parallel to the other two, but this was just to get us started and so far seems to already be more than we're currently using to charge phones and laptops.
 
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Sometimes adjusting the mppt is a good thing to do.  12.5 volts isn't going to fully charge your batteries.  Having said that,  I believe the manufacture knows best.  I would email the battery maker and ask them what you should be charging at.  Flooded lead acid,  I'm guessing closer to 14 volts than 12. I would trust the battery manufacturers recommendation over the MPPT guy because not all flooded lead acid 12v batteries are the same.

 
Jeremy Franklin
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Location: Binghamton, NY
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Thanks Chad. I'll do that.
 
Posts: 600
Location: Michigan
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A brief look for duracell charging info was not to be brief!

If you cannot find a charge profile from the manufacturer, the default setting for your type of battery will work fine. You can fine tune charge parameters aside from voltage set points and thats where it gets advanced.

Default settings can be a good thing!
 
chad duncan
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I agree with all of that.  I should add a clarification to what I said earlier about 12.5v not being enough.  When you set your mppt to the default '12v' it will actually charge it to a more appropriate voltage, likely around 14v. The mppt calls it 12v just to keep things simple for the user.
 
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