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topiflex avatar image
topiflex asked

Orion Tr-Smart 12/12-30A - LYNX BMS. At which point will the BMS disconnect Orion from charging?

Hi to all,

I have an Orion Tr-12/12-30A charing my Lithium bank (4x300ah) from the starter battery. All setting seem to be ok and the Orion charges the Lithium bank properly. All parts of the installation are Victron.


My question is:

The Lynx BMS does not disconnet the Orion from charging via ATC. Thy Lynx BMS allowes a Charge Voltage Limit (CVL) of 13.50 V or 14.20 V when starting a new cycle. These parameters are hard coded and cannot be changed. And it works well with the internal controled MPPTs for solar.

But the Lynx BMS allows the Orion to charge the Lithium bank well above the mentioned 13.50 or 14.20 V.

Even if the SoC is at 100%. It goes up to 14.90 V and still does not disconnect the Orion from charging via ATC. I know that the Orion is not internaly controled, but I think the ATC should disconnect at 13.50 or 14.20V once the SoC has reached 100%.


Or am I missing something?


Is there a way to stop disconnect the Orion from charging if the CVL reaches 13.50V via ATC? Or is this ok to let it charge until the CVL reaches 15.0 V? Maybe using a Cyrix Relay?


Many thanks!


battery chargingorion-tr smartlynx bms
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4 Answers
klim8skeptic avatar image
klim8skeptic answered ·

@Topiflex Even if the SoC is at 100%. It goes up to 14.90 V and still does not disconnect the Orion from charging via ATC. I know that the Orion is not internaly controled, but I think the ATC should disconnect at 13.50 or 14.20V once the SoC has reached 100%.

The Lynx BMS will cut charging under direction from the batteries BTV signals. The battery (and Lynx ) will disable charge when the cell temps go out of range (below 5c, or above 50c) or when the first cell goes above 3.75v.

Now if your Orion is still charging when the battery is at 14.9v, something is wrong. Check that the Orion has been set to the Std Victron Lithium settings.

Check that and report back.

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topiflex avatar image
topiflex answered ·

A bettery has 4 cells, so if a cell goes obve 3.75V would mean that the voltage at the battery is at 15.0 V (4 x 3.75V). All my cells always have an equal voltage during charging, so assuming that one cell goes to 3.75V means that all the cells would be at the same level.


BTW - Orion has been set to Standard Lithium settings.

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klim8skeptic avatar image klim8skeptic ♦ commented ·

@Topiflex so assuming that one cell goes to 3.75V means that all the cells would be at the same level.

Theoretically yes. Not what I have observed in 5 years. Recurrent days of full charge will typically have 10-20mV cell difference at the start of aborp. After a couple of weeks without a full charge, a 50mV difference would not faze me.

BTW - Orion has been set to Standard Lithium settings.

What is reporting the battery voltage? Check with your mppt (?) as they will record the batt min / max voltage for each day. Or VRM if set up.

Do check that you have an Orion 12/12 and not a 12/24. Seen that before.

Also check that the grounds of the Orion are clean, sound and tight.

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topiflex avatar image
topiflex answered ·

I have never seen a 50mV difference on my battery cells. 10mV - yes. In this case my batteries would charge up to 14.90V, but the ATC should disallow charging at 13.50 or 14.20. Which means 3.38V or 3.60V per cell. The lithium batteries have an internal protection to switch off charging once one cell reaches 3.75V, but it has nothing to do with the ATC of the Lynx BMS.

MPPT is reporting nearly the same values as the battery voltage. The whole systems works great - but not the ATC.

And yes, I have a 12/12 30A Orion ,NOT 12/24 :-)


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klim8skeptic avatar image klim8skeptic ♦ commented ·

@Topiflex The lithium batteries have an internal protection to switch off charging once one cell reaches 3.75V, but it has nothing to do with the ATC of the Lynx BMS.

No, the Lynx BMS can not directly control an Orion TR Smart other than enable / disable charge via the ATC relay, based on the The battery alarm signals and BMS actions .

When you fire up our engine the Orion will start a new charge cycle, regardless of what the batteries current Soc is. The Orion should respect the Lithium preset, charge to 14.2v, go to absorp for 2 hours, then switch to float 13.5v at the end of the 2 hour absorp period. It should not charge the battery above 14.2v.

You need to contact your installer / victron dealer, give them the details, and seek their advice.

PS, do you have an isolated, or non isolated Orion?

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Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

You really should take a look at the settings of your Orion.
The Orion shouldn't go up to 14,9V in the first place.

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