Upgraded MPPT and now not harvesting any solar ? (7 Viewers)

[Tombola]

not got my app, but Im sure you can drop the max current in it for now

 

[Raul]

Looking better:

View attachment 931135

That voltage is bonkers for a 12v system. If your panels are all equal, configure it with tho Y piece connectors in 2 series the two series in parallel. That controller will produce allot of heat to buck from 120v to 12. That voltage is for a 48v battery.
And do yourself a favour before magic smoke . Change the automotive fuse from controller to battery to a midi fuse and holder.
That fuse holder will melt eventually on 45-50amps.

 

[bigtwin]

I've got 4×100w panels and get about 20v max

Yes, but yours will be in parallel. The OP has explained that theirs is in series.

Ian

 

[Dorwyn]

I have a similar issue, but not quite the same. The solar has never shown any charge, it just reports that it is off. Apparently it will not charge until the voltage is less than 5v below the battery voltage, which has always been above 13.3-ish since the Victron mppt controller and the 100 amp lithium LB have been installed. But the solar panel does not show any voltage output from the panel at all. I seem to remember in the dim and distant, when I had a similar situation, someone said reverse the panel polarity, which I did, and it worked immediately. I'm reluctant to try that, in case it blows a fuse or worse on the Victron controller or something. So I accessed the panel leadson the roof, pulled apart the mc3 connectors, but my little meter probes do not reach the inner pins so I can't get a reading. I'm reluctant to bin the solar panel, because the replacement cost of a Truma 100 watt is 3 or 4 times that of a cheapo Chinese one. How can I check it?

 

[Dorwyn]

I have a similar issue, but not quite the same. The solar has never shown any charge, it just reports that it is off. Apparently it will not charge until the voltage is less than 5v below the battery voltage, which has always been above 13.3-ish since the Victron mppt controller and the 100 amp lithium LB have been installed. But the solar panel does not show any voltage output from the panel at all. I seem to remember in the dim and distant, when I had a similar situation, someone said reverse the panel polarity, which I did, and it worked immediately. I'm reluctant to try that, in case it blows a fuse or worse on the Victron controller or something. So I accessed the panel leadson the roof, pulled apart the mc3 connectors, but my little meter probes do not reach the inner pins so I can't get a reading. I'm reluctant to bin the solar panel, because the replacement cost of a Truma 100 watt is 3 or 4 times that of a cheapo Chinese one. How can I check it?

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[Dorwyn]

Whoops, double post, can't seem to delete it!!

 

[Tombola]

I have a similar issue, but not quite the same. The solar has never shown any charge, it just reports that it is off. Apparently it will not charge until the voltage is less than 5v below the battery voltage, which has always been above 13.3-ish since the Victron mppt controller and the 100 amp lithium LB have been installed. But the solar panel does not show any voltage output from the panel at all. I seem to remember in the dim and distant, when I had a similar situation, someone said reverse the panel polarity, which I did, and it worked immediately. I'm reluctant to try that, in case it blows a fuse or worse on the Victron controller or something. So I accessed the panel leadson the roof, pulled apart the mc3 connectors, but my little meter probes do not reach the inner pins so I can't get a reading. I'm reluctant to bin the solar panel, because the replacement cost of a Truma 100 watt is 3 or 4 times that of a cheapo Chinese one. How can I check it?

put the probes on the ends of the cables where it enters the mppt even if you have to disconnect them

 

[Lenny HB]

But 40 is a lot more than 25 hopefully the wiring is good regulator to batteries.

Replace the blade fuse with a midi fuse, blade fuses aren't very good with high currents.

 

[Lenny HB]

5m +/-

With the panels in parallel with 4mm² you will lose approx 6%.
Ifyour were getting max output in mid June you would lose 1.e amps of your 23 not enough to worry about.
In winter if the panels were producing 6 amps you would lose 0.36 amp again not enough to worry about.

 

[funflair]

With the panels in parallel with 4mm² you will lose approx 6%.
Ifyour were getting max output in mid June you would lose 1.e amps of your 23 not enough to worry about.
In winter if the panels were producing 6 amps you would lose 0.36 amp again not enough to worry about.

Isn’t that why he said he had gone series?

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[Dorwyn]

put the probes on the ends of the cables where it enters the mppt even if you have to disconnect them

Sorry, didn't mention I'd already done that. I wanted to be sure that there were no other fuses or contact points between the panel and the controller. There is a fuse actually on the controller, but since the light is flashing blue I assumed it had not blown.

 

[Ridgeway]

Isn’t that why he said he had gone series?

Yup

 

[autorouter]

So I accessed the panel leadson the roof, pulled apart the mc3 connectors, but my little meter probes do not reach the inner pins so I can't get a reading.

I'm not sure I should be suggesting a bodge, and I've not actually used MC3 connectors, but surely you can insert a pin or nail, something thin and metallic, that you can use as an extension to the meter probe. Obviously with higher voltages, over about 50V, you should take precautions against electric shock, wrap some tape round exposed parts etc. Especially if these panels are on a roof and you are working at height.

 

[Dorwyn]

I've tried that too. It's the uncertainty, because I can't see that the connection is secure. I've not even seen a flicker on the meter. Of course, it could be that the panel is knackered. Which is what I'm trying to prove! I'm thinking of cutting the solar end of the cable, if it's u.s. I'll need to change to mc4 anyway. I'll give it one more go!

 

[Raul]

I've tried that too. It's the uncertainty, because I can't see that the connection is secure. I've not even seen a flicker on the meter. Of course, it could be that the panel is knackered. Which is what I'm trying to prove! I'm thinking of cutting the solar end of the cable, if it's u.s. I'll need to change to mc4 anyway. I'll give it one more go!

It could be the connector, mc3 have been ditched long time ago as they corrode. Get mc4 staubli.

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