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geoleo · 30-09-2019, 11:55

I have 2 80 watt solar panels. The solar Controller went bad (red light Blinking) It is a Morningstar Duo Sunsaver 25 amp -2 batteries 12 volt about 16 years old. These are still sold . However shouldn't I get a MWPT style for a single battery as I switch them together for the boats 20 amp Heart Inverter anyway. ??? Do I really need a 25 amp for 6 T105 batteries and the 2 80 watt panels (old style ). ?? Are those "Tracer" mfg ones OK? Do I really need a MPPT style controller? Thanks everybody.

gaucho · 30-09-2019, 13:06

The solar controller should be based on your solar panels, not your batteries. Honestly in today's world I would look into the bluetooth enabled Victron offerings. They are pretty small, reliable, and the ability to connect to them via bluetooth to get the information you need is much more valuable than any lcd built into the system. Solar controllers are rarely placed in a visible spot, and it just makes sense to be able to monitor them thru our cellphone vs some lcd screen. That functionality also allows you to get a full day's or even a week of information to be displayed on your phone, which is much more valuable than a single reading of amperage and voltage at any given time.

john61ct · 30-09-2019, 14:18

What is the Voc rating of the panels?

thomm225 · 30-09-2019, 14:44

You may as well go ahead an upgrade to an MPPT Controller now that you need one.

They are way more efficient than a PWM and you can connect your batteries either in parallel or series

geoleo · 30-09-2019, 15:59

Quote:

Originally Posted by john61ct

What is the Voc rating of the panels?

Two -80 watt

geoleo · 30-09-2019, 16:00

Quote:

Originally Posted by gaucho

The solar controller should be based on your solar panels, not your batteries. Honestly in today's world I would look into the bluetooth enabled Victron offerings. They are pretty small, reliable, and the ability to connect to them via bluetooth to get the information you need is much more valuable than any lcd built into the system. Solar controllers are rarely placed in a visible spot, and it just makes sense to be able to monitor them thru our cellphone vs some lcd screen. That functionality also allows you to get a full day's or even a week of information to be displayed on your phone, which is much more valuable than a single reading of amperage and voltage at any given time.

I go sailing to get away from smartphones

john61ct · 30-09-2019, 16:09

Quote:

Originally Posted by geoleo

Two -80 watt

Voc is open-circuit voltage, nothing to do with power rating.

geoleo · 30-09-2019, 16:17

Quote:

Originally Posted by john61ct

Voc is open-circuit voltage, nothing to do with power rating.

Electric is my weak area --I cant imagine how electricity going thru a cold wire makes a light bulb hot!

john61ct · 30-09-2019, 16:19

So link to the spec sheet of your panels

geoleo · 30-09-2019, 16:21

There arent any- they are 15 yo and 2 different brands -on boat when I got it -they put out 18 volts-1 is made by a major oil company LOL

Uncle Bob · 30-09-2019, 16:32

Quote:

Originally Posted by geoleo

There arent any- they are 15 yo and 2 different brands -on boat when I got it -they put out 18 volts-1 is made by a major oil company LOL

Hi, I have the same controller (working) with similar panels and while I acknowledge that going MPPT will yield a slightly higher "harvest" there is also a slight internal consumption so in my case the nett gain would be minimal.
On the other hand if I were replacing the panels I would definitely go higher voltage panels with a good name brand MPPT controller. If you are happy with the existing panels then I would simply replace like for like and go sailing.