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squanto avatar image
squanto asked

SmartSolar MPPT 100/30 charging Dragonfly LiFePo4 batteries to 13.67?

Unit came with my Keystone Cougar 23MLE w/400i solar system. I have 2 x 200W panels and 2 x 100Ah Dragonfly LiFePo4 batteries as well as the Smart Shunt. I purchased the fifth wheel (new) in March this year and I have discovered the MPPT 100/30 was set to the default of AGM batteries and charging to 13.67V. Shortly after going through the Keystone instructions to set the MPPT and shunt for Lithium batteries, they charged to 14.2V for a day but then reverted to the 13.67V (Float).

I have rechecked the settings multiple times but it doesn't change. Neither device shows any desire for a firmware update. Anything I can do?


MPPT SmartSolarsmart solar set-up help
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Justin Cook answered ·

Floating at 13.6 for Battle Born (Dragonfly) batteries is appropriate. Are the batteries full? If so, then the controller won't (and shouldn't) be charging at Bulk voltages.

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squanto answered ·

Ok, so I think I understand now. The charger supplies 14.2v until the batteries reach 13.6v. That explains why the voltage goes to 14.2v every morning for an hour or so and then drops to 13.6V. Thanks for clearing this up.

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Justin Cook avatar image Justin Cook ♦♦ commented ·
Yep, that's just the 3-stage charge profile at work! Have a look at the charging section of the manual -actually the whole manual should be read, but in this case the charging section is particularly relevant to understanding what's happening!
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