Solar Outback 80 programming Tips

[a64pilot]

Well all I can say is you have either way more Solar than most, or use way less power than most, although I suspect both.
I and others leave their AGMs at absorption, although I rarely get to 100% SOC unless we go into town for the day and only have the fridge running, and it a great day for Solar.
Maybe in Summer, I have yet to go through a Summer aboard, we escape the heat and hide from storms in a Marina in Summer.
Maybe this is the year we get to leave full time, for real.

[Captain Bill]

Originally Posted by a64pilot

Well all I can say is you have either way more Solar than most, or use way less power than most, although I suspect both.
I and others leave their AGMs at absorption, although I rarely get to 100% SOC unless we go into town for the day and only have the fridge running, and it a great day for Solar.
Maybe in Summer, I have yet to go through a Summer aboard, we escape the heat and hide from storms in a Marina in Summer.
Maybe this is the year we get to leave full time, for real.

I was in the Bahamas and this might not be as big of a problem further north. I have 640 watts of solar and typically use about 150ah per day, though our record is 175ah, and typically 85 to 90 are used during the nominal night (when the sun is too low to put out any useful power). Of course by March there's a lot less night than in December. My boat is pretty electrically intensive, with refrigeration being the biggest consumer. My fridge/freezer is an upright that dumps all the cold air on the floor every time we open it. We also make ice in trays so that adds a lot of extra load. We have electric toilets as well. I typically turn on the inverter once we get well into absorption and charge computers and cameras. Even in the dead of winter I'm exceeding my usage by 9:00am and netting nearly 20 amps by 10:00 and in absorption by 11:00. I'm in the keys at the moment and getting into absorption by 10:30 when it's sunny. I replaced my old solar panels in December and got a new MPPT controller. My old solar panels were nearly 16 years old and were definitely putting out way below their rated power which was 300w. The new panels are nominally 39v and the old MPPT controller was only good to 25 v. We are about to head north to Maine, so we'll see how things go a bit further north.

[Pelagic]

Originally Posted by Dsanduril

+1, this is my setup. It took me about a month to get Peukert's set correctly on the Victron. It's hard to do when you're living on the batteries, much easier if you can take the load off and charge them fully. I put in the value in the manual, then charged to endAmps at absorption voltage, looked at how many AH the monitor told me were still out (even though batteries at 100% SOC) and used AH in from charger compared to AH in as measured by Victron to estimate an adjustment to Peukert's. After a little trial and error came up with a value that means the Victron AH count gets down to the low single digits about the same time as I reach endAmps on the charge cycle. The Victron is also programmed to reset at that point (I do use the automatic reset).

After setting it up this way on the very rare occasions when I can allow the batteries to rest the Victron is in pretty close agreement with a hydrometer down to about 25%DoD. I don't usually get much lower than that, so have never tested below that point.

Great to hear about the programing tips from experienced solar users, but also intimidating when I read of Bill’s experience with overcharging and destroying his AGM Batteries.

That may have happened to me when I moved ashore during refit and left the battery on Float with the default Victron Multi charger left on Float under the control of the BMW 600.

These were 8 x 8D Fullriver DC260-12v with a Puekerts Exponent of 1.18.
When I reconnected after 6 months they would not hold a charge, but being 8 years old, not sure if I had screwed them up by overcharging

I am electrically challenged when it comes to battery management, so here is my linear thinking and questions for advice:

1 I should Start with Batteries to identify local values adjusted for temperatures and Ratings

My new House bank batteries are 8 x Trojan 12 VOLT DUAL PURPOSE AGM BATTERY https://www.trojanbattery.com/product/8d-agm/

20-Hr Rate 230Ah / Capacity 24v = 920 Ah (less than my previous Fullriver 1040Ah)
24v CHARGER VOLTAGE SETTINGS (AT 77°F/25°C) Daily Charge 28.2 – 29.4v /Float 27v

If I subtract .028 VPC for every 10°C above 77°F assuming 35°C for Philippines does that mean I should set daily charge at average Daily charge – 28.8v-0.028 = 28.772v and Float at 27-0.028 =26.972V

Waiting from advice from Trojan on Puekerts Exponent so have set at default of 1.25

2 Victron Programing comes Next??
I have never adjusted any dip settings on the Victron Multi 24/3000/70 invertor charger, assuming I did this with the BMV 600…. Is that correct?
Default Multi Charge settings: Absorption voltage 28.8 V Absorption time up to 8 hours (depending on bulk time) Float voltage 27.6V.

As the Multi came with Voltage Sense and a Temp Sense connected to the House Bank, I assume that adjustment is done internally to the default setting…. Is that correct?

FYI, I connected my multi very simply with the AC In for charging and Invertor AC Out to an Invertor Supply in my AC Distribution Board, with Lockouts. It is not connected to “manage” shore power (see Photo)

So, I am assuming I should just change the settings on the BMV 600 to:
Daily charge 28.772v and Float 26.972V as per my calculations above…. Is that correct?

3 Lastly my 1,308W SunPower Solar Array, should Harmonize with Battery via the Outback Programing.

However, as I am often away from the boat with just Fridges running, should there be 2 programing modes:
One when on board and heavily consuming to maximize Solar energy
Second, to maintain and protect the Batteries …. Is that correct?

I changed the Neg Solar Cable to the NEG Bus as advised by Dsunduril and it works perfectly now (Thanks) (see photo)

Now I can monitor properly with both Outback and BMV600 , but I need first to confirm programming settings per your advice

I have also poured through the Glossaries of the Outback and Victron and did not find endAmps so trying to get up to speed on the terminology.
Thanks again for walking me thru this

[Dsanduril]

Well, the rest is certainly debatable , but endAmps is simply shorthand for 'the current at which the battery manufacturer recommends ending the absorption phase.'. I don't have a great connection or I'd look it up. Usually expressed as 0.007C or 0.005C where C is the bank capacity at the 20-hour rate. So, 920 * factor for ending absorbtion from manufacturer.

The problem with this is that if you charge with loads also running the Outback has no idea how much current is going to the batteries and how much is being used by load. The Victron knows, but it can't tell the Outback (I wish most charge controllers came with an external shunt option).

I don't recall if the Outback has current endpoint as well as time (I'll look later) but either way you are guessing - either the total current you usually see at the Outback when charging at endAmps and feeding the standing load, or at the time in absorbtion required to reach endAmps when feeding the standing load.

To do this I watch the current as reported by the Victron when reaching near the end of the charge cycle. It requires some note taking. Write down the time the Outback switches to absorb, and the time when Victron reports endAmps. Also write down the charging current at that point ( the difference is your standing loads). If you are never getting to endAmps then time in Outback needs to be longer or end current lower, if you get below endAmps all the time then the opposite.

[john61ct]

Yes in effect observing endAmps to calibrate the Absorb Hold eggtimer.

And needs adjusting with the seasons or as usage patterns change.

Ideal is the SC is regulated by a shunt based BM, but of course that costs more.

[CatNewBee]

at Pelagic...

There is one big mistake about your assumptions.
The BMV ( not the BMW ) is there only to show you the SOC, it does not control charging.
The charging profiles are in the used charger, MultuPlus for shore power or generator, solar controller for the panels. Each controller has its own independent setting. You have to check all of them or at least the most used sources.

[john61ct]

Generically speaking, when your system comprises SC(s) and a shunt / BM designed to coordinate with each other optimizing the charge cycle,

where the "decision logic" resides is an arbitrary design decision.

Sometimes the SC is in control, and just reads data from the BM on which to base its decisions.

In other such combo setups, the SC is dumb and the BM (or hypothetically an additional "central controller") takes over for more precise regulation.

[CatNewBee]

Well there may be such dessigns, especially with LFP, but for FLA setups usually every charge source has its own settings.The Victron BMV does have a programmable relay output, but it is rarely used to control absorption / float, it is a single contact. Without a bus system with a central unit that controls ALL charge sources, (shore power charger, wind gen, generator/ alternator regulators, solar controllers - all of them! - some have more than just one - etc.) it will not work. I am not aware of any commercially installed system that is set up that way.

Usually alternators, wind gens, solar, shore charger come from different manufacturer and do not use to talk to each other. I am not saying, it is impossible, but there is no such thing yet implemented.

[john61ct]

I was not talking about any other type but solar.

The BM reports trailing amps.

The SC transitions from Absorb to Float based on reading that directly, as per the user's programmed endAmps setting.

A half dozen solar makers have been marketing such combinations for many years before I ever heard of any mains chargers working that way.

[john61ct]

I believe Victron allows for this with the BMV / MPPT combo

I thought it required one of the "color GX" type remotes as well but recently someone posted not

[john61ct]

Blue Sky with IPN-Remote does this, also allows for "just stop" rather than Float, great for LFP

[john61ct]

Bogart Trimetric can control 2x SC-2030 I think 60A total?

Brilliant design, fully customizable profiles and super effective charging controls

Well worth getting matching 12V panels since PWM not MPPT

[john61ct]

Midnite WhizBang Jr, works with their KID or Classic SCs.

There may be others I'm not aware of at the high end, maybe Magnum, MasterVolt?

[CatNewBee]

Originally Posted by john61ct

I believe Victron allows for this with the BMV / MPPT combo

I thought it required one of the "color GX" type remotes as well but recently someone posted not

it works over Blutooth if both units have it (like mine)

[john61ct]

Whether BT or their VE Direct data cable is not the question. Assume no dongle-less products.

Can a Victron MPPT base its Absorb-to-Float transition on a customized trailing amps acceptance "endAmps" setpoint, as measured by a BMV's shunt at the bank,

with only those two components ?

Or is the Control GX required for that functionality?