Victron setting

[medsailor1]

Could anyone put me right with my victron MPPT setting .
My batteries are Trojan T125 .
Trojan data shots give bulk 14.85 and float 13.5
The setting on the Victron are for Absorption Max Absorption and float .
Has the Trojan data doesn't give Absorption V , what should I enter in the Victron setting
TK

[john61ct]

Set the voltage levels for everything but Float to the 14.85V.

Bulk CC is the first stage, charger "striving" to get the batt to that setpoint.

Absorb CV stage is second, after the batt getting there and 100% Full.

Say a full charge cycle with enough Amps available, takes 7 hours, Bulk may be one hour and Absorb six.

At low current, Bulk may last 6 hours and Absorb needed is only 2.

That transition is determined by chemistry, resistance, SoC, amps etc, not under control of the charge regulator.

[noelex 77]

The bulk and absorption voltages are the same for this algorithm. I thought Trojan recommended 14.70 v (2.45 x6 @25° C) for their flooded batteries, but whatever the number, set the Victron absorption voltage to this value.

Don’t forget that the voltages need temperature adjustment. The smaller Victron controllers on their own do not do this well, as there is no remote temperature input, although this can be done with optional accessories.

Often you are better to select manual temperature adjustment and alter the bulk and absorption voltages based on a manual measurement of battery temperature, but this will need changing for different seasons.

[Bleemus]

If I remember correctly the smaller Victrons do have a form of temperature compensation if you mount them in the same space as the batteries. Not as good as independent sensors but at least something.

[noelex 77]

Originally Posted by Bleemus

If I remember correctly the smaller Victrons do have a form of temperature compensation if you mount them in the same space as the batteries. Not as good as independent sensors but at least something.

Yes, they measure the temperature of the controller at start up and use this figure to modify the set points.

This facility can be disabled which enables a manual adjustment. In many, cases I think this manual adjustment is the better alternative.

[mikedefieslife]

Yep Victrons have a temp sensor built in, so if mounted next to the batteries offer some degree of compensation. There is also a bluetooth sensor that can be attached to batteries and feed multiple controllers with actual temp data.

[john61ct]

Going a bit higher than the manual spec is called for when trying to charge as quickly as possible.

Especially in a solar context as opposed to mains.

http://www.cruisersforum.com/forums/....php?p=2648005

[noelex 77]

Originally Posted by john61ct

Going a bit higher than the manual spec is called for when trying to charge as quickly as possible.

Especially in a solar context as opposed to mains.

6vdc Trojan T105 (225ah) Equalization - Page 6 - Cruisers & Sailing Forums

I do have some affinity for the suggestion of pushing the voltage set points at least to the high end of the manufacturer’s recommendation, and sometimes beyond these values.

Batteries can be damaged by overcharging, but often the adoption of aggressive voltage set points helps in maintaining a higher SOC when there is limited charging time. This higher SOC helps battery life.

However, I think it is import to recognise the manufacturer’s recommendation, which if my memory is correct, is 14.7 v, not 14.85v. The manufacturer’s recommendations are good starting point. Modification from these numbers needs to be considered carefully.

[mikedefieslife]

There is also a point where you have to ask it being super anal about your batteries is worth while. If by following the manufacturer's advice they last say 7 years (probably a fair bit longer), is it even worth your time to eek out an extra few months or even a year? Sometimes these things turn from having an active interest to being an obsession.

[jbinbi]

Can you set the times in the Victron charger as well? I have exide batteries. I try to get the water level well filled. Victron told me if I chose the right battery type, their default settings should be good. Or maybe they should be played with?

[john61ct]

Originally Posted by noelex 77

the manufacturer’s recommendation, which if my memory is correct, is 14.7 v, not 14.85v. The manufacturer’s recommendations are good starting point. Modification from these numbers needs to be considered carefully.

No, if you read that thread, the "published" specs are targeted to the mainstream overnight mains charging scenario.

Trojan invites you right in the doc, to contact tech support if you have a "need" for fast charging,

which does apply as soon as we are away from shore, and

then they reco the higher voltages, even touching 15V as I believe MS states.

[john61ct]

Originally Posted by mikedefieslife

If by following the manufacturer's advice they last say 7 years (probably a fair bit longer), is it even worth your time to eek out an extra few months or even a year?

Many owners get 12-14 years, for with a bank costing thousands, **for me** the answer is yes.

Plus for those who enjoy it as a hobby.

Remember, sailing itself makes zero sense from a strictly economic POV.

[john61ct]

Originally Posted by jbinbi

Can you set the times in the Victron charger as well?

If you mean Absorb Hold Time, then yes but not directly.

Measure trailing amps as the controller drops from Absorb to Float.

Tweak the settings until you observe, in normal usage, that it holds Absorb until current tapers to .005C, or drops less than .01V in an hour. That's a generic endAmps spec, Exide may publish their own if you can find it, not really a deep cycling brand. . .

For those often with insufficient energy to get there by sunset, some set Float = Absorb, but then you must check you aren't overcharging when more energy becomes available.

This issue (overcharging) is rarely a problem with FLA in a mostly-solar context, as it does get dark every night.

Of course keep water topped up.

[dutch-barge]

the settings for a Victron MPPT are easily adjusted by using there software. ( victronconnect app) You just need to get the correct voltages from Trojan, and set the MPPT accordingly.

https://www.victronenergy.com/live/victronconnect:start