A Pylontech / Victron question

It does a bit, doesn’t it.

Reading all the above, something tells me I am not even close to optimal values :frowning:



That is to be expected. Most installers install the strings well below their max voltage. As TTT mentioned overvoltage can be bad (although not so bad for Victron as they will just shut down to protect themselves instead on blowing up - very nice feature :smiley: )

The bottom graph is what we need. You battery current is well below the 85A limit, reaching only 56A the one day. This means you can easely and an extra string of panels to the same MPPT.
And yes the current will be clampped so any more than 85A will just not be used by the MPPT.

If you want to reuse your current DC cabling when you add a new string there is some optimising options. So instead of your current 4s3p you can make it 5s2p by adding a panel from your 3rd string to each of the other 2 strings and then use the 3rd strings cabling to add another 5s to get to 5s3p.
If you can’t find the exact same panels that you currently have you will be left with 2 extra from the old string. Either sell these and buy a new set of 5 or mix them with 3 panels that are close in spec.

This should give you the cheapest option to expand.

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Thank you, it makes sense…currently it is 4panels in series x 3…I definitely need to add a bit more in order to use the MPPT properly