Solar controller advice

[Formosa Scott]

I am putting three 305 watt 24v panels on my boat running a 12v system. I am a little confused looking at controllers. I am looking at a Outback 60a mppt and on paper I think it's sufficient. Do I need the 80a? Batteries right now are six 6 volt golf carts.

[noelex 77]

The Outback 60 is only OK for up to 800w of solar with a 12v battery system, so you will need the Outback 80 which is fine up to 1250w.

[Formosa Scott]

Thanks!

[motion30]

I have 3 275 watt Panels feeding into a 60-watt Outback. The maximum output I have seen so far was 50 amps

[tuberider]

I'm a little confused. Doesn't the panels have to be wired for 12V.

Sent from my Nexus 7 using Cruisers Sailing Forum mobile app

[motion30]

A mppt controller will work up with rated Voltage and convert it to 12 volts. In the case of the Outback controller it will take up to 150 Volts

[CAELESTIS]

Consider the Midnite MPPT "The Kid", or the Classic. Midnite was formed by the founders of Outback(prior to sale and subsequent move of manufacturing to India).

[tuberider]

I'm looking at the Blue Sky 3024 controller that does either 12v or 24v system. I asked them if I could put my four solar panels in series for 48v and they said their controller won't handle it. Are you saying that the Outback Controller will? I looked on the Web Page but didn't see any remote panels that could be flush mounted like Blue Sky's IPN Pro-Remote.

[noelex 77]

Yes the Outback will tolerate a much higher input voltage than the Blue Sky 3024. 48v is no problem. I think 150v is absolute limit.

However, I think parallel connection is probably the better way to extract the most AHrs out of the panel's on a boat, providing you have room for adequate cable size.

The Outback Mate (there is a Mate 2 and a more comprehensive mate 3) is a remote display/battery monitor that can be flush mounted. It will display the output from the outback 60 or 80. It can also be used to alter the parameters as well as a heap of other electrical information. Some other accessories are needed so it gets an expensive system, but is very good.

[sailormed]

If you mount your panels fixed horizontally, you will only get around 70% of total installed wattage. Take this in account for choosing your controller. I think you will fixed mount your 3 305 W panels and should target a controller capable of 640W.


Envoyé de mon iPad à l'aide de Cruisers Sailing Forum

[Paul Elliott]

Originally Posted by sailormed

If you mount your panels fixed horizontally, you will only get around 70% of total installed wattage.

This is probably true in terms of long-term average power, but the peak power at noon in the summer may be very close to the panel rated power. I wouldn't rely on this derating when selecting a controller -- you need to plan for the peak power.

[Formosa Scott]

Those were my thoughts when designing the system. I seriously doubt it will ever see 100%. What happens if it does on a 60a controller?

[Paul Elliott]

If you slightly exceed the maximum it will probably work OK. Or, it might explode. There's no way to tell. In general, it's not good practice to operate high-power gear at it's maximum limit. I don't know about Outback, but some manufactures are perhaps a bit optimistic with their ratings. Others are conservative.

[bill good]

Just one note of caution. Keep the wires from the controller as short as possible to the battery & away from other wiring to keep RFI down. The interference from an outback interfered with the VHF radio was bad. Wired the panels in series to keep the wire size down & be sure to include a fuse & switch in the circuit from the panels. Shading on the larger panels is not a problem due to bypass diodes. Go with the 80.

Regards Bill

[smac999]

on the victron mppt (atleast some of them) it will just limit the current. so if you have the 30a controller and you put more power into it. it will only put out 30a but be ok. but then you are wasting power. (and can probably only go over by so much without damage) just buy the correct size one.