Orion XS – Feature Request: Stop charging after absorption / disable Storage mode

DIY
, , , ,
1

Hello Victron Community,

I am using an Orion XS 12/12-50 in a somewhat unusual but potentially very useful camper application and would like to check whether the desired behaviour can already be achieved with the current firmware/settings. If not, I would like to suggest it as a feature request.

Application

The Orion XS is installed in a Mercedes Marco Polo MOPF2.

In contrast to the typical DC-DC application, the Orion is connected as follows:

95 Ah AGM leisure battery → Orion XS → starter battery

The leisure battery is additionally charged by solar. My intention is to use available solar energy and some of the leisure-battery capacity to support the starter battery while the vehicle is parked.

The background is that, in my experience, the current Marco Polo MOPF2 has a relatively high standby consumption on the starter-battery system. During parking periods of more than approximately two days, I have repeatedly experienced low starter-battery warnings and limitations of comfort functions.

My intended energy concept is therefore:

Solar → leisure battery → Orion XS → starter battery

The Orion should replenish the energy consumed by the vehicle while parked, but it should stop transferring energy once the starter battery is sufficiently charged.

Current configuration

I currently operate the Orion at approximately 5 A with:

  • Absorption voltage: 14.2 V
  • Float voltage: disabled
  • Storage voltage: 13.5 V
  • Adaptive absorption
  • Tail current: 2.0 A

The tail-current function works very well. Once the starter battery reaches 14.2 V and the charging current decreases below the configured threshold, the Orion correctly terminates the absorption phase.

The problem

After absorption, however, the Orion enters Storage mode and continues maintaining the starter battery at 13.5 V.

For example, immediately after entering Storage mode, I measured approximately:

13.5 V / 1.3 A / 18 W

Although the starter battery was already essentially charged, the Orion continued drawing approximately 1.4 A from the leisure battery.

Over several hours, this can represent a significant amount of energy. In one recent charging cycle, the Orion transferred 47.5 Ah over approximately 9.5 hours, while the solar yield during the day was only around 200 Wh.

For my application, maintaining the starter battery permanently at Storage voltage is therefore undesirable. I would rather preserve the remaining capacity of the leisure battery.

Desired behaviour

Ideally, I would like the charging sequence to be:

Bulk → Absorption → Tail-current threshold reached → Charger OFF

instead of:

Bulk → Absorption → Storage at 13.5 V indefinitely

The Orion could then restart charging when the starter-battery voltage falls below a configurable threshold for a defined period.

Conceptually, an additional setting such as:

“After absorption: Float / Storage / Charger Off”

combined with a configurable restart / Re-Bulk voltage, would be ideal.

My questions

  1. Is there currently any configuration in the Orion XS / VictronConnect that allows the charger to completely stop transferring power after absorption rather than entering Storage mode?
  2. Can the existing Re-Bulk functionality somehow be combined with a true charger-off state?
  3. If this is currently not possible, could you please consider “Charger Off after Absorption” as a feature request for the Orion XS?

I believe this functionality could be useful for many modern camper vans where the starter battery has significant standby loads and solar energy from the leisure-battery system can be used selectively to support it.

If this functionality can be implemented, I would also be happy to document and publish my Mercedes Marco Polo MOPF2 installation as a reference application, including the solar integration, Orion XS configuration and practical operating experience.

I believe the Orion XS is technically very well suited to this application – the missing element is simply the possibility to stop charging once the starter battery is sufficiently charged and automatically restart only when required.

Thank you for checking whether this is already possible or could be considered for a future firmware version.

2

Additional observation:
After enabling a 2.0 A tail-current threshold, the Orion correctly left Absorption and entered Storage mode at 13.5 V. However, shortly afterwards the starter-battery voltage dropped to approximately 12.8 V and the Orion automatically entered Bulk again, charging at the configured 5 A.

This creates exactly the behaviour I am trying to avoid: Bulk → Absorption → Storage → Re-Bulk → Bulk again, potentially repeating while the vehicle is parked and continuously transferring energy from the leisure battery.

Therefore, simply shortening Absorption or using the tail-current setting does not solve the application. What is needed is a true “charged → OFF” state with a separately configurable restart threshold.

3

What year of vehicle, what type of batteries, how old are they, and what are the battery specifications (eg charging, float voltages etc)?

Why haven’t you got a float voltage set?

4

It would help to know what other devices you have in your system.

I have an Orion XS 12/12 50 that can charge my leisure battery while driving. I have a Multiplus that has a 4 w trickle charge. When I have solar, even with the Multiplus off I can change my starter battery to keep it topped off in storage.

May want to look at what is powered off the starter battery and move some loads to the leisure battery.

Lastly, the Orion XS has the new feature to charge your starter battery for 15 minutes to give a jump start from your leisure if set up properly.

5

In expert user settings can you set float and storage to something like 12.8V or slightly lower which would be the voltage for an almost full lead acid battery.

6

Hello, here are a few more details about my setup and use case:

The vehicle is an approximately 10-month-old Mercedes Marco Polo MOPF2 with a 95 Ah AGM starter battery and a 95 Ah AGM leisure battery.

The challenge with the Marco Polo is the relatively high drain on the starter battery when camping without mains power. In particular, the electric sliding doors and tailgate wake up various vehicle and door control units. Depending on usage, forum posts report consumption of up to around 300 Wh per day. I’ve already been to Mercedes twice about this; the vehicle has been checked and all available updates have been installed. In my experience, the issue is less likely to be a fault and more likely to be down to the vehicle’s architecture and how it’s used when camping.

I’ve already had a low starter battery charge warning after the vehicle had been parked for around 1.5–2 days.

My setup:

220 W PV → Victron SmartSolar MPPT → 95 Ah leisure battery → Orion XS → 95 Ah starter battery

The Orion XS is therefore deliberately operating in the opposite direction to its usual application. It is intended to use up to around 5 A of excess solar power, or a limited amount of energy from the leisure battery, to support the starter battery.

Overall, it works very well. My only issue is the charging strategy once a high state of charge has been reached.

7

If you don’t need to charge the starter battery you could put the Orion in power supply mode at 12.6V. It would keep the starter battery fully charged while extended camping. I do this for a small 12V AGM house (leisure) battery from our 24V lithium system. The alternator charges the starter and that house battery through a contactor when driving, the DC/DC maintains it.

9

Thanks for your suggestions — I’ll give using it as a power supply a try.

Today, on a sunny day, I let it charge fully. It then stayed at 0 A in “Storage” mode for at least 3 hours (with the vehicle parked) before starting Bulk again.

My conclusion so far: a feature that lets you trigger the start of the next charging cycle based on the output battery voltage would be brilliant.

10

I think the XS is a bit of an overkill. Unfortunately, the product that makes sense for you isn’t made by Victron. The Votronic StandbyChargerPro is designed for exactly this purpose. The device lets you set the voltage to which the leisure battery can be discharged and the voltage at which the starter battery is trickle-charged. It’s activated via one input with a positive signal (permanent positive from the leisure battery, possibly via a switch) and deactivated via another input with a positive signal (the D+ engine-running signal), so charging stops when the engine is running. The maximum charging output is 8 A. You’d be better off connecting the XS the right way round and using the new emergency reverse-charging function.

11

That XS bi-directional charger is exactly what you’d want there. As soon as the XS firmware is better defined, I’ll be swapping out my dumb DC/DC for an XS.

Any DC/DC set to 12.6V stops providing current when the alternator output exceeds that value, just leave it on until you’re back in storage. There would be no need to charge and drain the battery over & over again when parked if the DC/DC can provide the standby consumption. It effectively removes the battery from the circuit.

12

Modern vehicles have batteries that can tolerate not being fully charged. The idea is that they can still take on charge when the vehicle is braking or travelling downhill. Some vehicles even have alternators that can act as motors to save fuel when pulling away. If it’s charged at 14.2 V, it will be fully charged. I’d set the absorption voltage to 13.6 V and limit the absorption time. Then set the float and storage voltages to 12.5 V and the tail current fairly high, so the battery doesn’t become fully charged.