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Luca Colangiuli avatar image
Luca Colangiuli asked

Clarification on minimim panel voltage for smartsolar mppt

Hi, i’ve on my van a 100w panel that output normally about 17/18. I don’t have the panel details as it was already installed on the van.

I’ve installed a smartsolar 100/20 mppt controller and a 100ah agm battery.


If i connect to the mppt via bluetooth i see that panel voltage is 15.79v and battery voltage 12.54

Battery state says “shutdown” (i guess this is the right translation, my app is in italian)

On the manual i read that:

● PV voltage must exceed Vbat + 5V for the controller to start. Thereafter minimum PV voltage is Vbat + 1V.

So if i’ve understood correctly if the panel voltage remain the same the smartsolar will start charge the battery only if it reach 10.79v, i’m right?

If this is correct probably it is bettee for me to reinstall the old pwm charger or to change the solar panel with an higher voltage one.


can someone help me on this?


thanks in advance,

Luca

MPPT Controllersbattery chargingsmart solar set-up help
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1 Answer
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

You are correct, where panel voltage is only a few volts higher than battery voltage, a PWM controller is better.

MPPT takes advantage when panel voltage is 2+ times higher than battery voltage, and 5V is the absolute minimum.

Update - @Johannes Boonstra (Victron Energy Staff) from Victron has made a short video that explains this in further detail - Q&A: Why does the Victron Energy MPPT starts 5Vdc above the battery voltage?

2 comments
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Luca Colangiuli avatar image Luca Colangiuli commented ·

This panel can be a good choice?

https://eu-solar.panasonic.net/it/modulo-vbhn325sj47-vbhn330sj47.htm#

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