# MPPT Calculator - Victron Energy BUG: lacks the max current going from PV into the MPPT

**URL:** <https://community.victronenergy.com/t/mppt-calculator-victron-energy-bug-lacks-the-max-current-going-from-pv-into-the-mppt/4777>\
**Category:** DIY\
**Tags:** victron\_community, mppt\_controllers, diy\
**Created:** [23 September 2024 10:00 UTC](https://community.victronenergy.com/t/mppt-calculator-victron-energy-bug-lacks-the-max-current-going-from-pv-into-the-mppt/4777 "2024-09-23T10:00:04Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Ardje](https://avatars.discourse-cdn.com/v4/letter/a/3ab097/32.png) [@Ardje](https://community.victronenergy.com/u/Ardje)\
**Post date:** [23 September 2024 10:00 UTC](https://community.victronenergy.com/t/mppt-calculator-victron-energy-bug-lacks-the-max-current-going-from-pv-into-the-mppt/4777/1 "2024-09-23T10:00:04Z")

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> **[MPPT Calculator - Victron Energy](https://mppt.victronenergy.com/)**
>
> Use our Online MPPT Calculator for PV sizing calculations.

I love the new calculator as it finally remembers my location.  
However:  
Under max low and high temp current of the PV it shows the max and min of the current out of the MPPT.  
The max low and high temp current of the PV should be way lower than that of the MPPT, and is important for the cables between the MPPT and the panels or combiner box.  
In the case of a 250/100, it says 100A going from the panels @ 200V to the mppt.

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**Author:** ![dognose](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/dognose/32/968_2.png) [@dognose](https://community.victronenergy.com/u/dognose)\
**Post date:** [23 September 2024 10:13 UTC](https://community.victronenergy.com/t/mppt-calculator-victron-energy-bug-lacks-the-max-current-going-from-pv-into-the-mppt/4777/2 "2024-09-23T10:13:55Z")

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> [@Ardje](#):
>
> In the case of a 250/100, it says 100A going from the panels @ 200V to the mppt.

That is a bit of a wording issue. What is denoted as `PV max current` is actually the current from mppt to bat. (And that - by the nature of a /100 MPPT - is 100A maximum.)

The currents flowing from the panel to the mppt are not shown anywhere. But PV-current is very fluctuating anyway, in either case it should not (for 2 parallel strings) exceed the rated `2 x 8.95A` of the TSM-255 Panels.

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**Author:** ![Ardje](https://avatars.discourse-cdn.com/v4/letter/a/3ab097/32.png) [@Ardje](https://community.victronenergy.com/u/Ardje)\
**Post date:** [25 September 2024 10:48 UTC](https://community.victronenergy.com/t/mppt-calculator-victron-energy-bug-lacks-the-max-current-going-from-pv-into-the-mppt/4777/3 "2024-09-25T10:48:28Z")

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They have fixed the issue now by having an advanced panel switch (fixing several posts mentioned here)  
If you turn on the advanced panel, you will see the panel parameters that the tool is using for the calculation, and well, you can take the Isc as upper limit.  
However the suggestion of which device to use is now a bit off:

- smart solar 250/100 does not exist
- smart solar 250/85 now is adviced max, and it doesn’t stop at 20 strings ;-).
- now the smart solar 250/100 exists again \0/
- And now an overpower of 250% is not possible anymore.

Victron is working hard 😉 Thanks for that.