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Hi @Remibggx a good question but unfortunately voltage is not really the full answer - this is especially true with lithium which will often sit between 13.2 and 13.3 volts regardless of charge. BMV’s are used because they measure current which is a better indicator of charge (fully charged when battery is above 14 volts and current is negligible).

That said. I would be more concerned that you are not getting the battery fully charged and the opportunity for cells balancing which occurs at 14.4 volts. You quoted the 12/24 Orion and 12 volt charge settings - is this the correct product or do you have a 24 volt system? Next what are the setting on the Orion - the default settings will not charge Lithium particularly well. Lastly how long is your available charge cycle and what is the source and what sort of load do you have (this is where a BMV or smart shunt would be helpful). With a bit of troubleshooting we should be able to get you up to a full charge. Also assuming you have a superpack with internal BMS - if not what sort of BMS are you using?

Hi Sarah,

Thanks for your reply :).

So here are my answers to your questions:

• My model is the Orion Non-Isolated 12/12 - 30A (I made a mistake above).
• I do have a 12V system in my motor home.
• I am attaching below the screenshots of my settings. As alternator type, I selected Regular Alternator, as I have a Fiat Ducato from 2010. In my recollection, it is not yet a smart alternator.
• My charge cycle is about 1 to 2 hours driving every day or every two days.
• Regarding my loads, for the most energy intensive, I have a MacBook 16 plugged with 2 external hard drives plugged to a 600W converter from Giandel (not Victron). The second most intensive is my diesel heater from Eberspächer, which requires lots of power when starting it. I am a photographer, and I am charging camera/drone batteries too, every couple of days. Beyond this I have the usual lighting (leds) and phone chargers about once a day.

I think that's pretty much it.

Thanks fr your help.

You don't tell us what voltage you see at the battery, or if it's increasing or decreasing over time.

Fact is that voltage, as @Sarah said, doesn't tell you an accurate state of charge. To get this from the BMS in the battery means extra circuitry, and with many installations having multiple batteries the extra cost is high. It's why the BMVs are available. One piece of kit for the installation. Sorry but it's the best way. Although some batteries give SOC readouts based on voltage, they're very inaccurate and we often see questions here about why the BMV and battery readings don't match.

Suggest you increase absorption voltage to the max for your battery, which I think is 14.4V. As long as the system switches to float, that batteries are being fully charged.

I've found that driving as little as you do doesn't provide enough charge through an Orion.

If float isn't happening, consider adding a second Orion in parallel, same settings. This will potentially double your charge rate, but make sure the alternator is up to it. Drawing 60A from the alternator, driving with lights on is going to put a continuous load of about 80A on the alternator. There's a good video on the Victron YouTube channel about problems with overloading alternators and how to prevent it, but the cost is high.

You might also consider putting a decent sized solar installation on the camper(my solution). But in winter you may still need a mains hookup.

My charge cycle is about 1 to 2 hours driving every day or every two days.

At 30A, that means maximum 60Ah (if there are no loads powered at the same time). You have a 160Ah battery. So it depends on how much you discharge it. Keep in mind that there are also loses.

What is the lenght and the cross section of the wires from the Orion output to the charged battery?

I would lower your start voltage to 13.2v and your shutdown to 13.0v. Without being able to monitor your alternator output you have not idea what it is doing. It could be dropping below 13.5v during your 1-2 hrs run time.

Hi, I am guessing that I have just been over optimistic with my battery capacity and the load I put on it.

After getting really scared with the battery putting itself in security and the charge never being completed, I managed to plug my MH to a 220V plug for few hours and then drove for about 40 minutes and got into the absorption mode soon followed by the float mode.

So, I am grateful for your answers, as they helped me foresee if I want to get a BMV or not in the future. As of now, I'll be more careful with the charging of my battery and might even consider purchasing a second one to ensure sufficient capacity for my activity.

Thanks again for all your replies.

Over 3.45 volts / cell is 100% with enough time.
see Offgridgarage for video proofs