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After updating the mppt firmware my battery charging isn’t the same.
i have 2 x 370w solar panels with 2x mppt 100/30 smart chargers.
With any form of daylight I am getting a charge and remains that way till dark but as of the update it seems as though something isn’t right.
i have daylight but no charge going in to the batteries. I have a -4.5amp draw and my batteries have dropped to 12.75 volts. Normally they are charging all day with no negative draw till dark.
Am I missing something here?
Hi @Hoverjocki
It looks like your panels are not configured correctly, so the PV Voltage is not getting high enough to start charging.
It needs to be at least +5V higher than the battery voltage (ideally much more). Your system is showing a difference of only 2.59 V (12.76 batV - 15.35 solV).
Solar voltage needs to be over 18 V minimum to start.
Your panels will need to be wired into a series configuration, they look like they are currently wired in Parallel.
Please read the Solar Section 4.10 of the Wiring Unlimited guide for more info.
They are single panels with their own mppt charger, they are not connected and are dependent of each other.
From the mppt chargers they out put to a bus bar then to the batteries.
Not sure I understand what I’m to do. 
Not sure what a good solution is for you either. Normally a 370W panel would be 60 cells, so should be providing DOUBLE the 15V you are seeing at your MPPT.
Something has definitely gone wrong somewhere.
Is there any shading on the panels, or partial obstructions of them? Clips, clamps, wires, tape, anything? It only takes a little tiny bit of shade when there is only a single panel.
Can you take an independent voltage reading at the panels themselves directly to see what voltage they are putting out BEFORE the cable run?
And then also test at the MPPT end to see AFTER the cable run?
How long is the wiring run from Panel to MPPT, and what size is the wire?
Can you take some photos of the panels, and the spec plate on the back?
Considering you are getting 15V from each of them, and that is why the unit is not starting up, That is the thing that needs to change.
If you have done all of that, and can't see any obvious issues, the last thing to do would be wire the panels into series at the panel end, and see if that gets the voltage high enough (and then only use one MPPT with 2 panels connected at 30V (but in that config should really be 60!)).
I took this pics off my iPad from earlier
I’m running 6 gauge wire 25’. From the panels the + goes through a blueseas 30amp circuit breaker then to the mppt charger. There are no shadows on the panels or obstructions.
Looks like the MPPT 75/15 low output question is having the same issue I am.
Hi @Hoverjocki, I am using the same 2 x LG 370 Wp set up, but with just one MPPT100/30. Panels connected in series, as @Guy Stewart (Victron Community Manager) recommends. Why use 2 MPPTs? When in series, the combined voltage does not go over 100 V, so one MPPT100/30 will work and you will much more easily reach the +5V the MPPT needs to start charging.
Hi.
This setup is installed on a sailboat. Im using 2 chargers so that if I get shading on one panel from the boom or when the sails are up it won’t diminish the power from the 2nd panel.
That’s the idea anyway.
Regards
Justin.
Hello @Hoverjocki, when you measure the PV voltage with a multimeter, what do you read?
best regards, Rob
