What Size Breakers Should I Use with My Victron 100/30 Controllers?

Question:

Hi Jeff, I saw your demo at the Vancouver Boat Show a few years ago and since looked it up in You Tube - Great job by the way! I am about to install 2 Panasonic HIT N330 (330 watts per solar panel). My question is the size of the breakers? I have ordered 2 x Victron 100/30 controllers and can place them close to my batteries. I have a 12v bank, a 24v bank and a starter bank. I also ordered a 10 AWG cable set. Latest dealer advice is to install 2 x flush mounted 60 amp breakers. Is that correct? Pity that I am not in Vancouver as I could as you guys to hook it up. - Paul

Answer:

Thanks for contacting PYS about your Halbery-Rassy. Your 330 watt panel will theoretically provide the highest amps at the lowest battery voltage. You’ll never get this theoretically value and perhaps get only 60 – 75% at best.

Theory: 330 watts / 10 volts = 33 amps.  Realistic: 15 -25 amps

As the charging goes (i.e. volts) up the amps will diminish.  Gauge 10 wire can only handle 30 amps continuous of current. I would recommend you go with a 30 amp breaker per panel installed as close as possible to the battery.  - Jeff