question

mike5fant avatar image
mike5fant asked

Issues with Victron set up in a Van

Hi! I have a 2-system configuration in my van where my 12v 110ah Agm battery supply my 12v-appliances and and a 24v 110ah lithium battery which supply my 220v appliances. I have a Orion Smart12v|12v-18A isolated DC-DC charger from victron which supply the 12v system while driving the car, a SmartSolar Charger MPPT 75/15 from Victron which that handles the power from the solar panels on the roof and connects to the 24v lithium battery and lastly I have a SmartShunt 500A/50mV from Victron to be able to se the status of the lithium battery.


My issue is that it feels like the settings I’ve set are wrong since even though the batteries are being and they haven’t been charged the SOC goes to 100% and I no longer know the status of the battery. I’ve watched the installation tutorial and read the manual many times and feel like I’ve made the right settings but it still feels like it’s not working properly. With the 12v it feels like it’s not being charged properly even though if I’ve been driving a couple of hours and the 12v battery is barely charged.


I was hoping that I could post some screenshots of the settings and see if someone would be able to help my sort it out if there are still some settings that are wrong :)


DC-DC Charger

1662446757155.png

8258aaf4-14ad-4174-b00e-02feb4a93a13.png

SmartShunt

1662446921523.png


Charge Controller1662446991933.png


Thanks!
/Mikael

MPPT ControllersSmartShuntSOCvictron productsorion dc-dc
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1 Answer
JohnC avatar image
JohnC answered ·

Hi @Mike5fant

You can tell when batteries are fully charged when they won't accept Amps at typical charge V. You can watch this yourself, and the Trends in VictronConnect or VRM are great to do this. And from there you choose the settings you want to use as a 'standard'.

Your Lithium.. You've chosen 26.2V as the point to sync the shunt, 0.2V below Float. That's quite low, even for Pb's, but inappropriate for Li's. They're often left at Absorb for a period to help them balance, but usually considered full before they drop to Float. Raise the Charged V to just below Abs, and drop the 5% Tail way down. Like below 1%, but you'll need to find your own point by observing them.

Your AGM.. There you've chosen the Spiral Cell preset, but unless they really are spirals, best to keep the Abs at like 14.4V. One of the Gel presets should suit. You didn't say why you think they're not being fully charged, but if they settle after a couple hours with no load on, to ~12.6V or so, then they've probably made it.


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mike5fant avatar image mike5fant commented ·

Thank you for the response! Some follow up questions:

- What does "Pb's" and "Li's" mean?

- For the lithium, do I change the charged voltage by looking at the absorption mentioned in the MPPT settings?

- Regarding the tail current 5% was recommended in the video regarding SOC and lithium batteries, doesn't the SOC go to 100% easier if the tail current is lower? And in what way do I find the point/observe the tail current and decide where to put it?

- Regarding the AGM, my battery is an AGM battery and that was the only option but I'm not sure if its a spiral or not. I dont think they are being fully charged because the voltage goes down to about 12v quite fast and has a hard time reaching over 13v. I always have a load on with a 12v fridge and a 12v fan, maybe I have to turn these of to try it out.


I will try the changes you suggested and hopefully it will work better, thank you!

Best regards, Mikael

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JohnC avatar image JohnC ♦ mike5fant commented ·
@Mike5fant

- Lead and Lithium.

- Yes.

- The lower the Tail, the harder it is to reach sync conditions. Li Amps should taper off quickly once Abs is reached, so mightn't matter too much. Your choice, but try to understand what's happening when you observe the A 'Tailing' off.

- If an 18A Orion struggles to reach 13V then the agm is well down, maybe even failed? It may also be switching off when it depletes the source battery below the setpoints. Can't help much with this, it's a local issue you'll need to check out yourself.

Good Luck.

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mike5fant avatar image mike5fant JohnC ♦ commented ·
Hi,

Okay then I understand a lot better, thanks a lot!


/Mikael

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kevgermany avatar image kevgermany ♦♦ mike5fant commented ·
If your 12V fridge is an absorption or Peltier type, they are a high constant load and can affect charging voltage.
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mike5fant avatar image mike5fant kevgermany ♦♦ commented ·

Hi!

Okay then I understand, thank you.


/Mikael

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