question

hiosilva avatar image
hiosilva asked

Victron Energy SmartSolar MPPT 100V 20 amp 12/24/48-Volt Solar Charge Controller- bad battery readings

We have had this controller on our pontoon keeping batteries charged for two years with no issues.

This year, we had to replace the floor and removed the system and reinstalled it.

We noticed that the Battery reading on the app did not match the reading on the console. In fact, we just ran down the charge until we had no power but the app still said we had 56volts.

We noticed that the system had failed to go into Bulk charging even though the batteries were depleted.

We disconnected the batteries from the controller but it still read 56volts.

We also noted that in bright sunlight, we were only getting 1-4 watts of charge from the 4- 100 watt panels.

Is it possible the controller is defective? I have tried all the settings but can find nothing to cause it to work. I have reverted to charging my batteries with a generator until this is resolved.

Thank you so much.

MPPT Controllers
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3 Answers
wkirby avatar image
wkirby answered ·

It seems that the battery is not connected to the MPPT due to a bad connection or an open fuse. You noticed that consciously disconnecting the battery made no difference, so it was probably not connected in the first place.
I'm pretty sure that the MPPT will not be reading 56V if you disconnect the PV or during the night time, which would further prove that the battery is somehow disconnected from the controller.
Check all fuses and connections first, it's unlikely that the MPPT is defective in this instance.

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hiosilva avatar image hiosilva commented ·
Thank you! I have checked all the battery connections and they seem to be fine.

I have no fuse from the batteries to the MPPT (perhaps there should be one?).

Yes, when I disconnect the PV or during night time, the controller goes dark and I cannot access it with my app.

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hiosilva avatar image
hiosilva answered ·

The Seller has agreed to replace the controller.

I have one more question about wiring to this unit. My cables are all 10 gauge but the inserts for the controller seem too small for the cables. What advice can you give to get the cables to fit the small holes. I have been just twisting the excess wires out of the way and clipping them. Is there a better way?

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vance avatar image
vance answered ·

You can use pin terminals, these will crimp on to end and present a smaller "Pin" or "Tab"

screen-shot-2022-06-07-at-102806-pm.pngscreen-shot-2022-06-07-at-102818-pm.png

https://www.mouser.com/c/connectors/terminals/?q=terminals%20PIN%20WIRE%2010AWG&contact%20material=Copper&type=Pin%20Terminal&instock=y&sort=pricing


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