Orion-Tr 12/12-30: "Power Supply Mode" vs "Charger Mode"

[StealthGTI]

Hello,

I don't have a solar system, but I'm building small and in a small platform while I learn. This system could someday wind up in a van. I've been searching for answers and have watched some videos that I've found linked here. No luck yet. So, I hope this is an easy question to answer for someone.

My setup (Functional Block Diagram below):

4x 100-Ah 3.2V Fortune LiFePo4 cells for 12.8V
RadioB Tech 4S 120A BMS
Orion-Tr 12/12-30 DC-DC Charger
4-gauge OFC wire between starter battery and back of car
8-gauge OFC wire between main relay in trunk and DC-DC charger

I had the Orion-Tr in "Power Supply Mode" the first time I cycled the battery since so many hams in my club just use a power supply to charge at 14.5V. This was my first time watching a LiFePo4 battery charge while monitoring the BMS via Bluetooth app. All appeared to go well. I used "Charger Mode" the next time to see if I saw a difference. From the perspective of the BMS, battery charging went well and I had no reason to suspect a problem. However, I noticed in the Victron app that the DC-DC charger spends a LONG time in the "Absorption" phase, even long after the BMS has reported that the battery is charged and current is zero. It will eventually go into "Float" if I drive long enough.

My question: Is there a benefit to using the Orion-Tr as a "charger" if the BMS is managing the battery charging current and/or phases? Would it be better to use the charger in "Power Supply Mode" and just let the BMS manage everything? Does it even matter? Does the consumption from my connected appliances "fool" the charger into staying in float? [edit] Could it be that the BMS app does not detect or report trickle currents that may be present before the charger enters "float?" [/edit] I appreciate your comments.

Thanks,

Scott

PS: If you're curious, here is a couple photos of my setup:

Full-size

Full-size

Full-size

 

[John Frum]

Hello,

I don't have a solar system, but I'm building small and in a small platform while I learn. This system could someday wind up in a van. I've been searching for answers and have watched some videos that I've found linked here. No luck yet. So, I hope this is an easy question to answer for someone.

My setup (Functional Block Diagram below):

4x 100-Ah 3.2V Fortune LiFePo4 cells for 12.8V
RadioB Tech 4S 120A BMS
Orion-Tr 12/12-30 DC-DC Charger
4-gauge OFC wire between starter battery and back of car
8-gauge OFC wire between main relay in trunk and DC-DC charger

I had the Orion-Tr in "Power Supply Mode" the first time I cycled the battery since so many hams in my club just use a power supply to charge at 14.5V. This was my first time watching a LiFePo4 battery charge while monitoring the BMS via Bluetooth app. All appeared to go well. I used "Charger Mode" the next time to see if I saw a difference. From the perspective of the BMS, battery charging went well and I had no reason to suspect a problem. However, I noticed in the Victron app that the DC-DC charger spends a LONG time in the "Absorption" phase, even long after the BMS has reported that the battery is charged and current is zero. It will eventually go into "Float" if I drive long enough.

My question: Is there a benefit to using the Orion-Tr as a "charger" if the BMS is managing the battery charging current and/or phases?

The benefit is proper charge termination.
It seems like current configuration needs tweaking.
The most common form of charge termination is an absorption timer which seems to be set to long.
The next most common form is tail current.
Have a look at the advanced settings in the charge profile and see what can be tweaked.

Would it be better to use the charger in "Power Supply Mode" and just let the BMS manage everything?

Probably not

Does it even matter?

Yes.

Does the consumption from my connected appliances "fool" the charger into staying in float?

Float for LFP batteries can be considered as "power assist" as in the charger helps the batteries with the load.
Float is optional.

[edit] Could it be that the BMS app does not detect or report trickle currents that may be present before the charger enters "float?" [/edit] I appreciate your comments.

When the charger enters float stage the battery have very little flow in or out unless the loads draw more than the charger can supply.

Here is a sample charge profile.
bulk/absorb=14.2 volts
tail current=5amps
float=13.4 volts
re-bulk=12.8 volts

Names may not exactly match on your charger.

 

[DJSmiley]

Neat setup!

Charger vs power supply:
When set properly, the Victron should go into float mode once the cells are full.
However, the absorbtion time is set by default for the LFP profile to 2 hours. You might decrease that if you want. I would set it to 15-30min or so. I don't see the benefits of 2 hour.
Check your settings and adjust accordingly to your preferences

Running it as a power supply would provide a fixed voltage. You can set this eg to 13.6-13.8V. That won't charge the battery as fast. Setting it to 14.2V or so is not recommended, since it will keep the batteries at that high voltage all the time, which isn't recommended for LFP.

Another disadvantage might be balancing. Depending on the settings, 13.6V might not trigger cell balancing. (Depends on how its configured). Most balancers do only balance at higher cell voltages. Altough the JBD BMS doesn't have a huge balance capacity (only 50mA).. it still makes sense.

And if you aren't planning to use the charger, you could have stick with a cheaper non-smart TR.


General:
- It seems the main fuse is an automatic thermal one. They usually are crap. Get hot / cause voltage loss, and might trip way before their rated amps. I would suggest a fixed MEGA fuse, and a breaker if you need to be able to disconnect.
- Seems there is a cover on everything. The Victron Orions Smart are known to get pretty hot. Based on the image there is <1" below/above the Orion. That's way insufficient cooling, especially with the cover. The orion will throttle since it cannot dissipete the heat, probably only giving 30a for 5min or so before it starts throttling.

 

[StealthGTI]

Thanks for the replies!

The most common form of charge termination is an absorption timer which seems to be set to long.
The next most common form is tail current.
Float for LFP batteries can be considered as "power assist" as in the charger helps the batteries with the load.
Float is optional.

Here is a sample charge profile.
bulk/absorb=14.2 volts
tail current=5amps
float=13.4 volts
re-bulk=12.8 volts

Names may not exactly match on your charger.

Here's how my charger is set, the two profiles I used.

The "User Defined" profile uses Will Prowse's recommendation as a baseline, which is a bit higher than default or what DJ recommended below. Will's thread does not contain recommendations for "Re-Bulk." I see that mine is set as an offset, 0.10V on both of these profiles. Is that 0.10V below float? In case the charger cannot maintain float due to the load? Do you recommend a different setting? Looks from your example that 0.60V may be preferred. What do you think? BTW, my charger has no settings for tail current.

When set properly, the Victron should go into float mode once the cells are full.
However, the absorbtion time is set by default for the LFP profile to 2 hours. You might decrease that if you want. I would set it to 15-30min or so. I don't see the benefits of 2 hour.

Running it as a power supply would provide a fixed voltage. You can set this eg to 13.6-13.8V. That won't charge the battery as fast. Setting it to 14.2V or so is not recommended, since it will keep the batteries at that high voltage all the time, which isn't recommended for LFP.

General:
- It seems the main fuse is an automatic thermal one. They usually are crap. Get hot / cause voltage loss, and might trip way before their rated amps. I would suggest a fixed MEGA fuse, and a breaker if you need to be able to disconnect.
- Seems there is a cover on everything. The Victron Orions Smart are known to get pretty hot. Based on the image there is <1" below/above the Orion. That's way insufficient cooling, especially with the cover. The orion will throttle since it cannot dissipete the heat, probably only giving 30a for 5min or so before it starts throttling.

I appreciate your comments! I'll set the absorption time to 15 minutes and see what it does on my drive tomorrow. I'll extend to 30 minutes if I don't think 15 mins is long enough. What do you think between the two profiles shown in the image above?

Regarding the breakers, I have them in place more for power disconnect than over-current protection. I have fuses throughout the system to protect from over-current. I use the breakers manually to make everything safe for when I need to service something.

I recognize the lack of space around my charger. As you suspected, there's a lid that covers that entire box. It sits about 1/2" over the charger. Here's how it normally looks:

I have a 3-inch fan blowing directly into the back side of the charger and four more fans along the front of my "rear seat delete" (some are visible in the OP). I've seen the charge current start at around 27A and then throttle to about 21-22A when the chassis reaches ~110 degrees. It seems to hold steady there. I have temp sensors so that I can keep an eye on things, especially during the summer. Oddly enough, I did a torture test on one of my transceivers last summer to see if my ventilation is effective. Without ventilation, the transceiver reached 140°F after about 90 minutes of drawing 12A, which is not how ham radios are usually operated. I'd say the vents aren't required under normal operations. With ventilation, the transceiver never exceeded 110°F. I expect the Orion to heat-up faster since it operates at double the power. But the fan is right on it, which should help. Also of help is the fact that the rear AC vents blow right in front of the fans. I guess I'll find out more next summer.

Thanks again for your input!

 

[John Frum]

14.5 volts is pretty high.
If your bms is tripping I suggest you knock it down a bit.
14.2 is my preferred number

I suggest you knock the float voltage down to 13.4 volts
That way your battery floats just below full resting voltage which reduces the stress on the battery

Hmmm adaptive absorption time suggests that there is a tail current component to the algorithm
If that is true your charger should go to float before the full 2 hours.
If that is not happening or you just don't like being absorption that long you could try setting the max absorption to 15 minutes.

Not sure how re-bulk voltage offset works.
Usually its a simple voltage.
When I used re-bulk I had mine set to 24.8 volts, but my usage model is atypical.
Maybe the doco will be illuminating.

 

[John Frum]

@StealthGTI is there a custom or expert option for "battery preset"?

 

[John Frum]

If you are charging from the sun your re-bulk criteria is the sun coming up.

 

[StealthGTI]

Thanks, Joey!

No tripping of the BMS. From the BMS app, everything looks to be working fine. The long absorption time after the battery is at 100% is my only concern. The "User Defined" selection is "custom" and allows me to change the settings. I can mimic the LiFePO4 settings, but change the max absorption time to 15 minutes... or 30 if I decide that 15 is not enough. IF absorption is supposed to begin at 80% and I'm charging at ~20 amps, then 30 minutes should get me to 90%. Perhaps my charging rate should dictate 45 minutes of absorption max? I can discharge to 50% or lower and then test to see when it leaves bulk and enters absorption. From there, maybe I can calculate an ideal time based on my typical charging rate.

I like you're analysis of re-bulk. I don't have solar, but my "re-bulk" can be defined by starting the car each morning.

 

[John Frum]

Perhaps my charging rate should dictate 45 minutes of absorption max?

30 amps is right in the sweet spot for 100ah of LFP battery.
At 14.5 volts I don't think you will need very much absorption at all.
Just entering absorption at 14.5 volts should have the pack plenty full.
That is assuming the wires are thick enough to avoid excessive voltage drop of course.
Would be good to know the voltage from the house batteries perspective when the charger hits absorb.

 

[StealthGTI]

Revisiting this...

- Seems there is a cover on everything. The Victron Orions Smart are known to get pretty hot. Based on the image there is <1" below/above the Orion. That's way insufficient cooling, especially with the cover. The orion will throttle since it cannot dissipete the heat, probably only giving 30a for 5min or so before it starts throttling.

While settting-up to test my new Bulk, Absorption, and Float settings, I also decided to relocate my charger to a place with more area for heat dissipation:

I moved it just six inches from its previous location, but out in the open. It's sitting directly over one of my cooling fans...

I need to pull the wires back a tad, but I'm pleased with the routing overall...

The top of the fins are about 1/3-blocked, but the fan pulls air through the top and bottom once the temp sensor (barely visible) reaches 82 degrees...

I had chosen my original location for concealment. While this location is "in the open," it's still fairly concealed by the fridge and when the front seat is in its normal position...

I haven't taken new photos of the battery pack. I had removed it, cut a new mounting board, painted it, re-installed everything, and started testing, all in a single day. I was running out of daylight when I took these photos and the paint was still tacky when I put it all back together.

Back on topic, my new absorption settings are good. I was unable to adjust "maximum absorption time" to less than one hour, despite it having 1-minute increments. The "adaptive absorption time" still just went into float after one hour. Regardless, I'm happy with how everything works and appreciate you helping me to understand the system just a little better.

Take Care,

Scott

 

[mikefitz]

You may find with the Victron Orion that its not possible to reduce the absorption time to less than 1 hour, seems to be a fault in the software. One hour is longer than ideal
Select adaptive absorption active, this will vary the absorption time depending on the battery state when the charger powered up.
The Orion runs very hot as others have pointed out, the resulting serious drop in output current may be the cause of your long charge time.
Settings I use,
Absorption volts 14.00
Float volts 13.35
Reconnect 13.25
Absorption time 60 mins ( the latest software may have corrected the issue of not being able to go lower)
Adaptive absorption active

Mike

 

[StealthGTI]

Thanks, Mike!

Select adaptive absorption active, this will vary the absorption time depending on the battery state when the charger powered up.
The Orion runs very hot as others have pointed out, the resulting serious drop in output current may be the cause of your long charge time.

I forgot to mention in my previous post that moving the charger to a more open location has given me about 3A more charging current than in its previous location. I don't ever see the full 30A. But I think that's because the charger may be more of a "360W charger" (360/14.2=25.3) than a "30A charger" (360/12=30). This morning's drive showed 23-24A for most of the charge time. Of course, the unit was plenty warm, but had air being drawn thru by my fan.

I'm using the recommended charge settings for LFP batteries, plus adaptive absorption is active. My drive tonight started with the battery at a high SOC, around 99%. It started in Bulk, quickly shifted to Absorption, then switched to Float just 30 minutes later. So, that's progress.

My charger powers-down within 20 minutes of engine shutdown because of the way my factory power feed is setup. I have a relay that disconnects main battery from the back ~20 minutes after the alternator shuts off. See K1 and APO3 in the functional block diagram in my top post. As a result, the charger always starts in bulk, even if the LFP battery is at a high SOC, since it's booting from nothing. I could change that by connecting the charger directly to the main battery now that I'm more confident about the charger's isolation effectiveness. That would keep the charger in float or absorption until it's supposed to switch back to bulk. However, that would also leave the charger energized 24/7. I sort of like turning it off. Thoughts?

Anyway, I'll go for another drive tomorrow to see if it enters float as quickly as it did today, then see how it behaves in float during the drive. After that, I'll feel like I've learned the system's behavior well enough to trust that it works and just leave it be unless I discover a problem.

 

[John Frum]

I sort of like turning it off. Thoughts?

The charger can and probably should be controlled by a relay that only closes when the ignition is in the run position.

 

[DJSmiley]

Remove the jumper lead on the orion and use a D+ to enable it.

You don't need a massive relay (capable of the full current for the Orion - about 30-40A) and can use the H input on the Orion.

If you have a D+ that will be +12V only when the alternator is running, and will start the Orion.

You can use an ignition wire as well, but the disadvantage is that will enable charging, even without the engine running, thus eventually draining the starter battery. The D+ is only active with a running alternator.

I have the same setup in my van, using the D+. I also added a switch, since I have solar panels, there isn't always need for the DC-DC to charge if there is sufficient sun available. My DC-DC is only used when there isn't sufficient solar available.

See page 9.

The Orion also has a smart alternator detecting feature, but I personally prefer to configure everyting as static as possible, any smart thing may 'smartly' fail as well. A D+ wire doesn't leave any room for smart mistakes: It's either there (thus alternator running) or not.

 

[StealthGTI]

Thanks for the comments, DJ! Everything in my schematic, aside from the charger and LFP battery, was already present in my trunk area. So, "K1" was already there and handling the entire load any time the engine is running (my "D+?"). I added the LFP battery after several years to extend my "engine-off" operating time with the ham radios. K1 is where I chose to split the load between the starter battery/alternator and the LFP battery. I could run a thin wire to the remote input of the charger, but it would just be switched by the same source as my primary power wire. It seems to be working well as currently wired.

Today's "float test" seemed to show that the charger enters Float fairly consistently around 25 minutes after entering Absorption. K1 de-energizes if the car sits for more than 20 minutes. When I return, even after 21 minutes, the charger starts in Bulk, quickly shifts to Absorption, then returns to Float after 25-ish minutes. So far, I have not driven long enough to see the charger leave Float to "Re-Bulk." I guess I'll get that chance on a planned road trip in January.