2017/18 LTV Unity TB Lithium Upgrade Questions

[VanIslVan]

I am considering a Lithium Upgrade for our 2017/18 Unity TB.

We currently have the OEM Isolation Relay Delay (IRD) and Solenoid under the passenger seat.

i am considering the Victron Orion 12 12 50 for DC DC charging of the house Lithium battery.

I understand there is some question as to whether the settings in the Orion can reliably and efficiently assess whether the engine is running, and therefore determine whether the “smart “ (?) alternator is running. This reolaces the IRD and Solenoid function to ensure that charging of house battery only occurs when alternator is running.

Is this correct? Do others have experience with this? Does the Orion work as desired with the 2017 alternator?

Rather than removing the IRD and Solenoid, would it make any sense, in a “belt and suspenders” approach, to keep the IRD and Solenoid and to install the Orion “downstream” of them. That way, there would definitely only be power to the Orion when the engine and alternator are running.

Or is this a dumb idea, and it would be better to remove the IRD and Solenoid and just install the Orion, letting it decide on when to charge the house battery or not?

Thanks in advance for any assistance in this!

PS - does the 2017 Unity TB Sprinter Chassis have a “smart” alternator? Is it known to cause trouble with DC DC charging?

 

[not logged in]

I have the Victron Orion XS installed in our 2018 UTB. I don’t think the 2017 Sprinters have a smart alternator, but our Orion does seem to be able to accurately detect if the engine is running or not. In addition, I added a switch to be able to easily turn the Orion on and off (if generating plenty of solar or if next stop has hookups, no sense using the Sprinter’s alternator to charge the house batteries). It’s easy to connect the Orion to a switch, but mounting a switch is more work. It’s also pretty easy to turn the Orion on and off with the Victron app. I would completely bypass the IRD and solenoid (I just abandoned them in place).

 

[mikeme]

I have an XS installed in my 2015.

It has a rich set of capabilities, and does not take much current when enabled and watching for the engine voltage to satisfy settings. (like one amp hour in a bit over a month.)

I measured the current used and is close to the specifications.

I turn it off for the off season using the app. (or if my use is between hookup sites, why pay for more fuel for the engine if not needed?)


In normal use, you do not need a switch, but you can install one, or use a wired interface from the engine running signal to assure positive control that the unit is not charging. (or both. ask me for more details if you like)

Most important is to follow the instructions from Victron, and pay attention to wire and fuse guidance. It does a swell job if mounted vertically,, and suffers from heat stroke if you insist on laying it flat. In that case a fan can provide some relief.

I put mine under the step with a 300 Ah battery. I disconnected the activation of the solenoid and moved one of the large wires to the other terminal. this lets my smart shunt keep track of the starting battery, since the starter battery wire ends up in this compartment to feed the XS.

 

[not logged in]

In normal use, you do not need a switch, but you can install one, or use a wired interface from the engine running signal to assure positive control that the unit is not charging. (or both. ask me for more details if you like)

I used the ignition/engine running signal wire (the wire originally connected to the blue IRD wire) with a switch to control the Orion. Unless the Orion detects voltage on the ignition wire, it won’t turn on to send output to your house battery bank. This way even the switch is left on, if the engine isn’t running, the Orion won’t charge.

 

[SSTraveler]

I don't use engine detection with my Orion-XS because I haven't found it reliable when you're also using a chassis battery charger. When my house battery charging sources are used for my chassis battery charger (like a House2Start, Victron 18a Orion-Tr DC-DC Charger, Xantrex ECHO-Charge, Trik-L-Start, Amp-L-start, or external chassis battery charger). It considers the higher chassis battery voltage when it's being charged as the engine running, so it starts a do-loop of battery charging that eventually runs down both chassis and house batteries. I would rather use a a solid state ignition controlled isolator relay to actually isolator the Orion-XS from the chassis battery when the ignition is off. It's more reliable and has a longer life. I don't recommend reusing the mechanical isolator solenoid and a isolator relay delay units, because the Isolator Solenoid is prone to failure. Here are videos of that. Everyone I know who installed a Victron Orion-XS under the passenger seat, no matter if it was installed horizontally or vertically, has had overheating heating issues. So I highly recommend installing a 92 or 120mm 12vdc cooling fan when you install it. You definitely need to open the top ofvthe seat base to get more airflow. Here is a video where I replaced an isolator solenoid with an Orion-XS. I also installed a Xantrex ECHO-Charge chassis battery charger. About 6 months later the Xantrex failed and my friend was having issues with the Orion-XS overheating. The second video is where I added a cooling fan and a House2Start chassis battery charger. All has been working great!

 

[SSTraveler]

Mobile Solar Consulting offers a really nice Orion-XS fan that is adapted right to the unit.

 

[Mike DZ]

(or if my use is between hookup sites, why pay for more fuel for the engine if not needed?)

It might have been just bad luck, but I had a string of occurences where I arrived at a campground and their electricity was down. Based on that, I have applied the Boy Scout motto approach and charged all my onboard storage during my drive time (previously replaced generator with ECOFLOW).

 

[mikeme]

It does pay to plan ahead. I really have too much house battery for what we do. for a single long night, 50 amp hours is about what we use. For some of our trips when we drive between hookup campsites, it makes sense (to me) to leave the dc-dc charger off. When we plan more nights off grid, the reasoning is different.

On the related note to this string,

Yes, if you have anything else charging the starter battery than the alternator, the XS engine shutdown detection will not be the only need.

It does, however, come in handy, and can be used in conjunction with the engine running signal.

It is also possible to wire up the wired remote using a single pole double throw switch to give options related to use of the "engine on" signal. one with a center off position would let you select off, on, or engine control.

 

[mikeme]

I will also say that the XS install manual is quite clear that the unit should be installed in a vertical position.

With enough airflow, it works well, and silently.

Installed in the closed space under the seat, it mostly works fine, but if run at full output in hot weather, there is not enough air flow to get rid of the heat, and the unit will derate, that is lower output current (and the proportional waste heat).

If you need to put two in, or operate in very hot weather, it is a good idea to do two things, in addition to mounting in the vertical position.

One is to insulate the floor of the seat base. In hot weather, driving, between radiated road heat, engine heat and just plain hot weather heat, that floor can get hot.

Second is to install some fans in a way that they actually bring cooler air into the space. it is also important to have an opening to let warmer air get out.

Power in minus power out = power wasted as heat.

If there is too much heat under the seat, fans right on the charger will not do much to remove it from the area.

 

[VanIslVan]

Thank you to all for your n formative responses. As usual, I have gained useful knowledge.