Einschaltstrombegrenzung für Balkonkraftwerke ‐ Inrush current limiter

Einschaltstrombegrenzung für Balkonkraftwerke - Inrush current limiter

As the Hoymiles Inputs have a limit of 15A (more for the HMS models), people ask if there is risk when connecting a battery with the Hoymiles.

A general rule says: Do NOT connect a Solar Panel while it is producing under the sun, to an inverter!

The same should then apply when connecting the inverter with the battery!

There are various opinions and at the time of this article and no clear opinion on what the best way to do the connection should be.

Overall, it appears that the big Electrolytic Capacitors (Kondensatoren) at each Hoymiles Inputs need to be charged. When the Capacitors are empty and connected to the battery, they will absorb a lot of power very quickly - as the battery can provide power way over the 15A max allowed, this may be risky. (A side-information: while in use, the Hoymiles will regulate the max. input from the battery to approx. 10A)

I have collected below some opinions I found over time, consider them just as "food for thought":

• If you buy a new battery, it may be helpfull to check if your battery has a "soft-start" function.

• ich empfehle den Wechselrichter erst über einen hochohmigen Widerstand aufzuladen und dann volle Leistung drauf zu geben. Der Inverter hat am Eingang große Kondensatoren, die geladen werden wollen. Das gibt ordentlich Funken aber der Inverter ist deshalb nicht kaputt. (I recommend first charging the inverter via a high-impedance resistor and then applying full power. The inverter has large capacitors at the input that need to be charged. This causes a lot of sparks, but the inverter is not broken because of this.)

• Die Eingangskondesatoren lade ich vorher mit einem schwach beschienenen PV Modul auf und schalte dann die Batterie zu, sie bleibt dann permanent angeschlossen. Ein und ausgeschaltet wird dann nur noch die AC Seite des Wechselrichters! (I charge the input capacitors beforehand with a slightly-illuminated PV module and then switch on the battery, which then remains permanently connected. Only the AC side of the inverter is then switched on and off!)

• An interesting (german) Discussion ist here Stromeinschaltbegrenzer? - Hoymiles HMS 1600 4T - 24V/100Ah LiFePo4 #528 and here https://github.com/helgeerbe/OpenDTU-OnBattery/wiki/Impact-of-high-start-currents-to-the-inverter

• A (german) company offers a PCB solution for "Einschaltstrombegrenzung für Balkonkraftwerke mit Speicher" for 25V Batteries. A YouTube Video shows the spikes when connecting the battery: Balkonkraftwerk mit Speicher - Wechselrichter zerstören There is also Documentation: Currentlimiter-v2-0.pdf