SmartCharger 100/30 MPPT

[Tsu]

I’m New here!

My new Charge controller is flashing blue. (Australian summer)Not for a lack of sunlight.

Connected to a solar panel and a battery it shows Zero charge.

Interestingly. when disconnected from (12 LFP 300AH) battery, there’s ‘solar’ 38 volts detected on the screw heads.

But when battery, (with and without a VE Smartshunt) is connected, Volts detected on the screw heads is close to zero.

So: PV generates. Charge controller’s flashing blue. Charge controller not charging, and: when all 3 connected, there’s zero V on screw heads?

I will appreciate community’s help.

[lxonline (LX)]

Its possible your battery bms has shut down.

Then there is also the possibility that there has been a reverse polarity as well.
When there is a problem the mppt shorts the pv side.

Are you able to post screen shots from the app?
What settigs have you done there?

[Tsu]

You are a Legand. lxonline.

I have attached settings for my other charge controller. the 150/45 Max charge was 35A. (I doubt that’s a problem?)

To check connected VE lfp 12/5 charger. and it was charging.

Thank you again,

[lxonline (LX)]

Nice. Glad it was something simple.

@Tsu

charge was 35A

Not related to the issue. Can the battery take the amps in charging, sometimes they are limited for that reason.

[Tsu]

Oh No. The 100/30 Solar charge controller is still not charging! ‘have a strange feeling Solar charge controller is having a ‘tantrum’ settings or something. Please don’t give up.

Will try Solar charge controller again tomorrow, will try to document what-I-see. (How do I reset to factory, start again?)

[lxonline (LX)]

Sorry i misunderstood.

I assume by your troubleshooting with the removal of the shunt you also checed fuses and connections.

If you disconnect solar, disconnect the battery,
Wait 3 minutes.
Reconnect the battery. Does it read voltage? Does it read voltage with the other charger charging the battery? If not then something is afoot.

Does the app show a message like the charger is off for some reason?

[Tsu]

Dinner time here.I thank you so much. (Santa might come to you. Zwarte Piet if you are bad!) Will try all this and report tomorrow.

[pwfarnell]

You may have a poor connection on the PV supply. If you have no load you see PV volts because there is no current to cause voltage drop over a high resistance poor connection. As soon as you connect a load you loose voltage as current flows through a high resistance poor connection causing voltage drop. People keep thinking a voltage measurement at no load means the system is working. You need to do a short circuit current test on your PV system at the MPPT end of the wires.

[Tsu]

Good morning. I hope I understand your reply?

10A limit on my multi tester, can’t perform short circuit current test.

have attached a few screen shost.

Panel’s generating 50 off volts. (No dc Ameter SadFace).

Connection is firm and tight

[MikeD (Mike)]

@Tsu

10A limit on my multi tester, can’t perform short circuit current test.

You can use that to do a short circuit test on the modules in lower level light. The Isc on your modules may be below 10A anyway, 9.6A is fairly common. But if you do that test in the evening and get 5 - 6 A, that should be ok.
@pwfarnell , I think if the PV was high resistance, then the PV voltage would drop to ~1V above the battery voltage, not go to zero. This seems to be indicative of a strange fault.

[Tsu]

1000 thanks to you all. It’s working!

I made the dumbest mistake! I used MC4 cables that a friend/installer cut off His, new panels. To connect to Control charger.
Now my connection to charge controller polarity was wrong! (Am I explaining this correctly?)
Tell me if you think I should post illustrations? help others avoid this small mistake?

Just one more thank you.

[lxonline (LX)]

@Tsu

Now my connection to charge controller polarity was wrong!

You will be surprised how common a mistake it is on the PV side. Hence the built in protection for it.

If you want to share -feel free. I am sure there will be people who appreciate it.
Thats what this forum is about.

[Tsu]

Imagine two identical panels with MC4 connections.

Someone has cut the cables of one one panel to shorten.

and gives it to me.

One cable has a red stripe,

Connectors can only be connected to their opposite plug. (short to long finger in this image.) And before-you-know it, I’m inserting the wrong polarity into charge controller terminal!

Merry Winter solstice all.