Choosing MPPT solar regulator(s)

[Bob666]

Hi!

Bank 1
GEL (Euro)
House bank 300 Ah

Bank 2
Open acid
Start battery 75 Ah

Solar array # 1
3 x 100 W in series. Same brand, model batch and current. 36 V.

Solar array # 2
Multiple solar panels totalling 200 W. Same brand = same voltage. 12 V.

Buying MPPT regulator. Not interested in PWM. Will buy one of these brands:
Victron Solar Controllers, MidNite Solar, Outback Smart Harvest Controllers, Morningstar Controllers, Blue Sky Solar Controllers or Western Solar Controllers.

Are there MPPT regulators that can connect two solar arrays with different voltage? If yes, do they do that on the same input port or on separate ports?

Can you connect multiple solar panels in parallel to one MPPT regulator? If yes, is that valid for all MPPT regulators? Prerequisite: all solar panels have backing diode inbuilt. Same brand so same voltage.

Suspecting answer to above is "you need two MPPT regulators."

If so, I want to charge battery bank # 1 with MPPT regulator # 1. With MPPT regulator # 2 I want to charge battery banks # 1 and # 2.


Will I be able to synchronise the two? Will that make sense as they are doing slightly different work? MPPT regulator for array # 2 will be charging two battery banks. Will I be able to set charging current percentage to bank # 1 vs. bank # 2, for example if I want bank # 1 to recieve 80% charge and bank # 2 20%?

The MPPT regulator for solar array # 2 must be configurable for battery type. I.e. battery bank output port # 1 and # 2 must be possible to configure for GEL vs. open acid, respectively.





Cheers

[Bob666]

Or can I skip voltage sensing if I mount the MPPT regulator connected to array # 1 fairly close to the house bank and have thick cables?

[Paul L]

The Blue sky controllers can work together with a single display panel. I use 2, one for each bank of solar.

[Bob666]

Hi!

I am emailing with BlueSky. They cannot charge two different battery banks if they have different chemistry, which mine have.

I am going to buy panels for array # 2 from here:
Teknik för alla väder Den nya generationens Flexibel Solpanel - 21,5% effektivitet

They only have flexible panels.

Array # 1 on arch will be solid panels. Will buy cheap to mid range stuff, not the most expensive marine panels on the market. 3 identical panels.

I want to give the start battery at least a little push from solar. Again, one of the two regulators should charge the start battery a little.

I haven't bought the start battery. I will buy something cheap. Is Global ok? They're really cheap. Or pay slightly more for Tudor?

Teknikhamstern state you should only have one MPPT regulator and parallel connect everything into that regulator. Or you might face the problem of one of the regulators seeing high voltage on the battery bank and turning off = no charge from its solar panels. They are right, but the cabling for array # 1 will much easier if I do it in series and they will get very little shade.

Morningstar says:
SunDuo PWM can charge Start + house bank (Array # 2) (http://www.morningstarcorp.com/products/prostar-mppt/)
+
PS-MPPT-25M ( http://www.morningstarcorp.com/products/prostar-mppt/ ) for array # 1 (serial) ONLY charge house bank.

They do not communicate with each other but they state:
" The PS-MPPT-25 and the SS-Duo can also share one of the battery banks and it should not be a problem. As you mentioned, the PS-MPPT does have remote temperature and voltage sensing, however the SS-Duo only has remote temperature sensing (no voltage sensing). The controllers do not actually communicate with each other, but this should not pose a problem as the PS-MPPT can current limit based on the real-time voltage it measures at the battery. As long as you use the same charging profile for the shared battery and initiate the controllers at roughly the same time, they should stay in sync throughout the battery charging stages."

Can I trust that, please?

I am going to buy regulator(s) from any of these companies
Victron Solar Controllers, MidNite Solar, Outback Smart Harvest Controllers, Morningstar Controllers, Blue Sky Solar Controllers & Western Solar Controllers.

Found the list here:
http://www.pbase.com/mainecruising/solar_panel

From my limited knowledge, I will buy same brand for both regulators.

Another option would be to parallel couple also Array # 1 and connect everything to one MPPT regulator, top of the line, 45 A or so. Pain in the ass though. Cost-wise the same I'd same, more cables and time consuming.

Cheers

[sailormed]

Buy an echo charger to charge the 2nd bank from the first and still keep 2 separate banks. Should be a cheaper solution.


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

[Paul L]

Why not use a charge relay like
https://www.bluesea.com/products/cat...harging_Relays to get your starter battery charged. Then put all your solar toward your main bank.

[Bob666]

Interesting

So two high-end MPPT regulators, one for each array, then I can choose good stuff that is 100% synchronised (seems problematic with the major brands, if one of them charges both a house bank and start bank).

Will this work:

Alternator and old battery charger (shorepower) to Sterling (Alternator to Battery Chargers up to 130A | Sterling Power Products)
Sterling to house bank.
Sterling START output to start battery.

2 x MPPT regulators (each array) to house bank.

House bank to echo charger to Start battery.

Correct?!

Cheers!

[Bob666]

Originally Posted by Paul L

Why not use a charge relay like
https://www.bluesea.com/products/cat...harging_Relays to get your starter battery charged. Then put all your solar toward your main bank.

Do you mean a simple relay? Too simple? I've either overlooked or won't work with my config.

So the two charge controllers go to a relay with two outputs:
1. house bank
2. start bank

I don't think that's what you meant?

Cheers

[Paul L]

Sounds like overkill. The start battery will get charged when the mains are being charged is the ACR. You don't need any other special charging for the start battery. It will get charged with the main banks profile, gel, so may have a slightly less life, but it is just a low-cost Smal
battery.

[Bob666]

Sorry, but I don't understand the cabling.

I got two banks of different chemistry, 1 Sterling, 2 regulators (synchronised).

How do they connect to each other, please? What else do I need?

Cheers

[Paul L]

Look at the wiring diagram for the ACR on theBlieseas site. Automatic Charge Relay connects the batteries

[Bob666]

Will. Do you mean no Sterling?

Cheers

[Paul L]

Originally Posted by Bob666

Will. Do you mean no Sterling?

Cheers

https://www.bluesea.com/products/cat...harging_Relays

[Bob666]

Hi!

In my list it seems only Blue Sky Energy Inc. - Industry Leaders In Solar Boost Charge Controllers and Maximum Power Point Tracking (MPPT) have synchronised MPPT regulators. They also have a. Auxiliary port to charge battery bank # 2.

Perfect, if it weren't for the fact they don't seem to support panels connected in series. Their top-end model, see:
Blue Sky Energy Inc. | Our Products

Supports max Voc of 40 V. I think Voc of a single panel is +20 V so won't even be possible to connect two in series.

Why is this so when the other brands support up to 110 V etc? Strange.

Or am I missing something?

[txg]

Get two Votronics, one for each solar array. Good german company.

VOTRONIC - MPP 350 Duo Dig.

Their MPPTs have a second output (13,8V/1A) for the starter bank.

I do have two of them and like them a lot.