Solar MPPT Controllers to consider

[sailorxyz]

I have used Genesun MPPT controllers for more than 10 years now. Have yet to have a failure. Current setup is 6 140watt panels (open circuit voltage is 28V) feeding through 6 Genasun controllers (each panel has it's own) feeding into a 12v battery bank. Setup has worked well and I'm happy with it.

[Wireless1]

Originally Posted by noelex 77

The maximum DC voltage should also be checked. Often this is a greater issue as many DC switches cannot handle the 60+ volts of larger panels. Suitable switches can be found, but you need to be careful assuming “standard” marine switches will be suitable. Often these are limited to 32v DC. There is a very real fire risk using these switches to interrupt higher voltages.

Some solar arrays need fuse or circuit protection on the input side of the solar controller (as well as the output side). This is not common in marine installations, but if required a circuit breaker is generally simpler and neater than a fuse and switch.

So true! With most of us using our meager lower voltage (30VDC os so) panel or two and usually in parallel we easily tend to forget those guys like on big cats with tons of solar real estate available! They can easily get into series/parallel setups that do have high voltages. In my small setup I have a total of 680 watts using 4 SunPower E-Flex 170 watt flexible panels that I have converted to rigid panels with 8020 aluminum extruded frames and 6mm ThermoClear Lexan backings. This gives me two 170w flexible panels totaling 340 watts in each frame (680 watts for the two frames). And each combined panel of the two 170's weighs half what a 340 watt glass panel weighs. But each of my single 170's has its own Victron 75/15 SmartSolar controller with Bluetooth networking to my Victron BM 712 BlueTooth battery monitor. With the entire system networked all the controllers work as one receiving the info broadcast from the SmartShunt BM-712. Pretty cool of Victron to work this out. And the best part is their firmware and software updates that can also be done over BlueTooth. I was amazed when I first fired up the system to see that there was software and firmware that needed updating. And I was able to update the BM-712 and each one of the four SmartSolar controllers with my my iPhone! LOL... As a bonus fitting all 680 watts of solar on top of my bimini, saved thousands in construction of a custom solar arch on the stern, plus saving the added weight of that arch. Though I did have to add a few extra stiffening tubes to the bimini frame but it's all working well know and I'm very happy... I'm still on LA batteries but I do already have 16 Voltronix 160 AH LiFePO4 prismatic cells that I'm waiting to switch over to for the house. But I've got to save up some $$$ to get that all worked out.

[Jef & Marin, Netherlands]

Your choice options might be reduced if you want to use lithium batteries.

As I understand, with Lithium batteries the current insight is that they can deteriorate if you float them with constant voltage once they are full. You need to terminate charging completely when they reach for instance 3.5V per cell.
While some solar controllers say they have a Lithium setting, they do not terminate charging. Please check for this.



Since it is a recent insight that you should not float LiFePO4 batteries, when I chose 2 Morningstar MPPT60's I did not check them for this. Luckily I found some post on the Cruisers Forum where somebody had figured out a setting (checked by Morningstar) which does the charge termination. I have since been using this custom setting, after using float for 5 years. Which seemed not to have damaged the batteries.

[mitiempo]

Originally Posted by wackerb

I had two Victrons on my last boat and they worked fine, but will not buy another as long as their connecting blocks are too small to accept properly sized wire. What a stupid place to economize!

What size wire have you tried to put in which model controller?

I have installed many systems, most with Victron controllers. The small ones (75/15 series) take 10 awg without a problem and the larger controllers (100/30 for example) have no problem with 6 awg with the proper ferrule crimped on - may even take 4 awg but I haven't tried.

[Manateeman]

I’m on DIN rail fuses, power blocks. Controller: Schneider Conext 60 150 MPTT.
Solid commercial stuff.
6 volt Rolls 5000 series, four, gives me 700 AH at 24 Volts.
Six 285 panels.
Outback inverter.
The Schneider runs perfectly.
Happy trails to you
Captain Mark and his electric orchestra manatees

[Sternwake]

While I hate tempting fate...

I've been using a Blue sky 2512i continuously , since 2007, regretably not the 2512ix, which allows for a battery temperature sensor.

I have The IPN pro remote interface which allows me to change settings and monitor the batteries.

Mine can only handle 12v nominal panels, I have 198 watts, occasionally add 100 more, and rarely 200 more.

The faceplate is a heatsink. I've never noticed it getting warm, much less hot.

While Big heatsinks might be a great thing, I kind of look at them like the old diode based battery isolators. That heat being wasted energy.

My 2512i has endured being disconnected from the battery in full sun at full output, unintentionally, more than once.

I've got some issues with the IPN proremote's ability to accurately quantify battery state of charge, but with a healthy AGM battery it does pretty well in regards to amp hours from full. With older flooded batteries that still accept a fair current after switching to float, not so much as it seems to go above zero and takes 7 to 10 amp hours of removal before it starts counting properly which then makes it appear the battery is performing noticeably worse than it actually is.

I've only limited experience with other solar controllers, so no opinion on other brands, Just posting to share my relatively positive experience of the Blue sky controller, SB2512i, with the IPN pro remote to adjust it, for the last 13 years.

It's not perfect by any means, but its faceplate/heatsink never gets hot with upto 300 watts of panel feeding it, and it has survived at least a dozen load dump situations, disconnected from battery in full sun in bulk mode which can instantly fry many a controller.

My only regret regarding it, was not buying the sb2512ix model, which allows for adding a battery temperature sensor.

I've not kept up with the recent MPPT offerings, and hope I do not need to anytime soon.

My huge peeve with all controllers is, I would much rather they allow for a ring terminal be attached, rather than insert stranded wire, perhaps in a ferrule, then tighten screw and crush/ lock it in place.
This screw needs regular retightening and if no ferrule is used the copper stranding oxidizes, and then these terminals heat up and waste solar wattage.

These insert stranded wire, and crush under screw terminals, are an insult to the consumer.

Someone who cant properly attach a ring terminal to wiring/cabling, should not be wiring a solar system up in the first place, so allow for a real electrical and mechanical connection, instead of something which coddles the incompetent with a doomed to fail highly resistive no tools required terminal, other than screwdriver.

[Simi 60]

We have a midnite classic 150 mppt looking after our 9 x 250w panels.

Been doing its thing trouble free for 4 years.
Probably looked at it twice in that time. (Oooh, black box....next to blue box)
Set and forget.

[CaptainRivet]

Originally Posted by wackerb

I had two Victrons on my last boat and they worked fine, but will not buy another as long as their connecting blocks are too small to accept properly sized wire. What a stupid place to economize!

+1 for Victron, the best value and in features

My Victron 100/50 has decent connection blocks, up to 16qmm is more then enough....you place the MPPT as close to battery as possible, the Voltage of the solar is always higher then your 12V output (in my case 35V to 50V) and it makes perfect sense to use the long cable here...6mm2 12m long is oversized for 38V and 15A and also 1m in 10mm2 for 50A, the max the Victron delivers.

Beside features MPPT is not the same as MPPT...the Victron tracking and efficiency is far above others. This plays a major role if you connect different solar panels with different voltages to one MPPT. In my case I have 2 x 100/50 Victron, one for the 2x LG 355W neon2 on the Davits and one for the rest which are different size semi flexible ones on the roof of the pilot house and 2x 120W fixed on the reling. That was before on the MPPT from silent wind gen controller (you can connect 20A solar too) and on a renolgy MPPT one. After switching to Victron I got 30% more output in total for the “rest array”, especially on cloudy days the output is far better up to 70% as the tracking of the Victron is far superior to the others and can harvest much more from what comes from the different panels on one MPPT compared to even 2 Controllers before. A tested also difference with one big panel ( as both old ones can only handle 20A each, so one 355W panel) and here difference is still noticeable around 10% on cloudy days, only when full sun on there is a very small difference.

[sv Stella Maris]

Victron almost always. Wait...never say always, right...okay, except for Victron, hehehe.

It isn’t that they have a monopoly on quality MPPT’s; it’s that they make EVERY component you likely will ever need and they all work together nicely.

For something stand alone or a very simple install I might let cost or features sway me a bit.

[SalingSue]

Victron.

They work, they work well and price wise they are not even crazy expensive.

Why mess with a good thing?

Solar, AC charger, combiners, BVM, Victron all the things.

[fritzdfk]

I have a Victron controller and 2 panels wired parallel. I have a bluetooth dongle and I like having that info. If I were to buy another controller so each panel had its own how would the bluetooth work? Would I need a dongle on each controller?

[seandepagnier]

I built my own MPPT so I can have one for each panel , It cost about $12 to build low quantities for 10 amp version up to 60 volts. It could be cheaper in quantity.

I get 18% increase in power compared to direct battery connection.

https://hackaday.io/project/174537-solar-powered-boat

[mitiempo]

Originally Posted by fritzdfk

I have a Victron controller and 2 panels wired parallel. I have a bluetooth dongle and I like having that info. If I were to buy another controller so each panel had its own how would the bluetooth work? Would I need a dongle on each controller?

Yes you would need 2 dongles.

Or you could buy a smart controller with the chip built-in for less.