Outback upgrade versus total rebuild to all Victron, or other

I have a off-grid island cabin running on an Outback system centered on a 24V FX3524 inverter installed in 2007. This is part of an old-school prebuilt system that includes the inverter, AC and DC breaker boxes and the charge controller together on a single mounting plate. Over the years I swapped out to an FM-80 charge controller and a Mate3s so that I could take advantage of Outback’s internet monitoring and control system (Optics RE).

Flash forward to 2024, and the FX3524 continues to chug along, but for a variety of reasons, it is time to upgrade to 48V and lithium. The dilemma I face is that the simplest move would be to buy the modern versions of the Outback FX inverter (VFX3548) and charge controller (FM-100). These could be dropped into place on the existing mounting plate, and with a few breaker swaps, the upgrade would be finished. Another point favoring Outback is that my local solar installer primarily installs Outback systems.

I am wary of Outback though. Over the intervening decades, Outback has been bought and sold several times, and they were just purchased by Big Battery. This has not been widely announced, but the new president of Outback acknowledged the purchase and engaged with the Outback User Forum community recently regarding a nearly-week-long outage of the Optics RE online communication system. Even before this latest sale, I felt like Outback was adrift, especially with respect to the off-grid market. I suspect Outback hardware purchased now would be nearly as robust as their older hardware, but I am particularly concerned about the long-term prospects for Optics RE since remote monitoring and control are critical for my use case.

So, do I go with the simple (and thus less expensive) choice, stick with Outback and roll the dice that the new owners of Outback will support the hardware and monitoring software long term? Or do I look elsewhere? Given my situation, I would like to go with a well-established manufacturer with good remote monitoring and controls. I am already partially in the Victron world on the battery side so it would be a reasonable choice. A Midnite system is also a consideration, but the equivalent Rosie/Classic combo would be pricey, and I’m not sure I can wait until Midnite’s new AIO is available.

I know there is no single right answer here, but any thoughts and suggestions would be appreciated.

I like outback, and I'd heard the rumors, but yeah.. Victron. No question. It's actively developed. The owner's son is the CEO and he manages the development of the Venus OS. They have firmware updates on the regular. THe majority of their employees are developers and engineers.

There's been an issue with VRM from time to time, but the good part is that multiple Victron folks are on their community forum (including the CEO) giving updates and an ETA on the fix.

I recently became aware that during the pandemic, Victron experienced explosive growth on the order of 60%, and they recently had a significant price reduction across their offerings.

Yes. I'm a fricken' smurf, but I wouldn't consider any other option EXCEPT maximizing the existing system and avoiding the upgrade altogether. While the FX3524 may not support LFP explicitly, it might be able to be configured to work acceptably with it.

Thanks sunshine-eggo. In a way I already have the FX3524 supporting LFP. In order to keep things running over the winter I needed a quick battery fix but was not able to tackle the system as a whole at the time so I opted for Victron 24v 200amp hr batteries x4 paired with the lynx system (and Cerbo), including the lynx smart BMS. I know the LFP Victron batteries are not the cheapest, or necessarily favored even by smurfs, but the fact that they can be put into a series configuration to go to 48V let me hedge my bets. So for now I am running at 24v and have programmed the Outback side of things to charge the Victron batteries, but with the Victron smart BMS standing sentinel ready to shut things down in the event of an over temp or overcurrent scenario (low temp is a bit unclear and something I am trying to clarify). Not to mention the whole issue of fusing at 48 V (the T-class fuse vs. Megafuse debate, again).

I could carry on at 24v for a while, but I also want to upgrade my solar panels. I am in dense trees except one narrow window so I can’t change the square footage, but 2024 panels can nearly double the output in the same footprint compared to 2006 panels so the time seems right. This will necessitate, at minimum, a charge controller upgrade to handle the new PV voltage and amperage ceiling which would be simpler with a 48V upgrade . Also due to State solar incentives, and the typical technology upgrade cascade, I think I have locked myself into a 48V upgrade. If Victron had better fixed-installation, US-friendly, charge controller options, that would help make the decision to go to an all-Victron system easier (nudge..nudge Victron you know you should to do it). Otherwise I may be looking at some odd hybrid of Outback Inverter, Victron battery/BMS and a Victron vs. third party (?midnite) charge controller running at 24V. This seems like a remote-monitoring nightmare in the making.

dang... you went off the deep end!

Well, since they lowered their prices, they're at least cheaper than Battleborn now.

I'm not following you on the seeming lack of US-friendly charge controller options. What do you mean?

kcbuild said:

they were just purchased by Big Battery

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Do you mean a big battery company like Enersys?
Or do you mean Big Battery in the San Fernando Valley?

Yep... BigBattery.com


President of Outback and BigBattery CTO

sunshine_eggo said:

dang... you went off the deep end!

Well, since they lowered their prices, they're at least cheaper than Battleborn now.

I'm not following you on the seeming lack of US-friendly charge controller options. What do you mean?

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Yep. Definitely off the deep end. But I can switch from 24 to 48V with just a few cable and fuse changes. It helps that I have a local Victron dealer that I can actually walk in and talk to and get parts and supplies, usually the same day.

I've been watching Victron installation videos on You-Tube and combing the forums as I try to get my mind around an all Victron installation in my setting. What I see is that most of Victron charge controllers seem focused on the mobile market and all lack provisions for conduit which makes for some awkward installations for those trying to meet at least the spirit of North American code in their installations. I was looking at both the Victron VE-panel and the Midnite e-panel available at Current Connected and neither offer a method for mounting a Victron charge controller directly to the box I think because of the design limitations of the charge controllers. As noted on some of the forums, a range of conduit-capable, fan-cooled charge controllers would help address this.

kcbuild said:

Yep. Definitely off the deep end. But I can switch from 24 to 48V with just a few cable and fuse changes. It helps that I have a local Victron dealer that I can actually walk in and talk to and get parts and supplies, usually the same day.

I've been watching Victron installation videos on You-Tube and combing the forums as I try to get my mind around an all Victron installation in my setting. What I see is that most of Victron charge controllers seem focused on the mobile market and all lack provisions for conduit which makes for some awkward installations for those trying to meet at least the spirit of North American code in their installations. I was looking at both the Victron VE-panel and the Midnite e-panel available at Current Connected and neither offer a method for mounting a Victron charge controller directly to the box I think because of the design limitations of the charge controllers. As noted on some of the forums, a range of conduit-capable, fan-cooled charge controllers would help address this.

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With native 240v split phase in a single unit also. And get a UL Listing on the LYNX POWER IN busbars already.

sunshine_eggo said:

President of Outback and BigBattery CTO

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I still don't see any indication that Enersys sold off Outback. I assume Neipert left Big Battery to become CEO of Outback.

kcbuild said:

Yep. Definitely off the deep end. But I can switch from 24 to 48V with just a few cable and fuse changes. It helps that I have a local Victron dealer that I can actually walk in and talk to and get parts and supplies, usually the same day.

I've been watching Victron installation videos on You-Tube and combing the forums as I try to get my mind around an all Victron installation in my setting. What I see is that most of Victron charge controllers seem focused on the mobile market and all lack provisions for conduit which makes for some awkward installations for those trying to meet at least the spirit of North American code in their installations. I was looking at both the Victron VE-panel and the Midnite e-panel available at Current Connected and neither offer a method for mounting a Victron charge controller directly to the box I think because of the design limitations of the charge controllers. As noted on some of the forums, a range of conduit-capable, fan-cooled charge controllers would help address this.

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If I go with Victron for another system, I’ll just use my stock pile of Sunny Boy 7.7s and AC couple and not worry about SCCs. If I didn’t have those, I’d look at Fronius line inverters.

Maybe not the most efficient system overall, but shines in the sunshine.

Ampster said:

I still don't see any indication that Enersys sold off Outback. I assume Neipert left Big Battery to become CEO of Outback.

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Sorry. Meant to post this:


Still a very short leap to BigBattery, but I think it's enough to go on.

kcbuild said:

Yep. Definitely off the deep end. But I can switch from 24 to 48V with just a few cable and fuse changes. It helps that I have a local Victron dealer that I can actually walk in and talk to and get parts and supplies, usually the same day.

I've been watching Victron installation videos on You-Tube and combing the forums as I try to get my mind around an all Victron installation in my setting. What I see is that most of Victron charge controllers seem focused on the mobile market and all lack provisions for conduit which makes for some awkward installations for those trying to meet at least the spirit of North American code in their installations. I was looking at both the Victron VE-panel and the Midnite e-panel available at Current Connected and neither offer a method for mounting a Victron charge controller directly to the box I think because of the design limitations of the charge controllers. As noted on some of the forums, a range of conduit-capable, fan-cooled charge controllers would help address this.

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Ah... Well, they're spendy as shit, but the RS450/100 or /200 address your concerns.

Ampster said:

I still don't see any indication that Enersys sold off Outback. I assume Neipert left Big Battery to become CEO of Outback.

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I used the wayback machine to confirm that Enersys did remove Outback from their "family of products" on their website sometime around March or April this year.

What I'm more confused about is the relationship between Signature and Big Battery.

I was running a Radian with Flexmax controllers and an FLA battery bank. I am now running a Sol Ark and lithium.

Here is what I learned: If you stick with an Outback inverter like a Radian 48 volt, the onboard charger does not directly communicate with lithium batteries. But it will charge them just fine IF:

Batteries such as Pytes offer directions for configuring the Outback Power onboard chargers for Outback inverters and Flexmax charge controllers. After those settings are made on the Outback side, the BMS of the Pytes secures proper charging.

So a simple upgrade would be to a 48 volt Radian and lithium stack keeping your Flexmax chargers and combiner boxes intact.

Otherwise, in my case, I wanted to upgrade to a high voltage MPPT charge controller and a closed loop lithium battery system for ease of use by other persons if I am unable to maintain system. I chose Sol-Ark for this task. BUT, at my combiners, I hade to remove the lower voltage parallel PV strings and replace with a single serial high voltage string. This meant new breaker in the combiner box, new fuses in the combiner box and a new DC disconnect switch. All needed the proper amperage as well as 600 VDC ratings, not 250VDC ratings. So that was extra work. Also my Midnite surge protectors were all upgraded to 600 VDC at the combiners.

But once done, the new closed look system works great.

kcbuild said:

Yep. Definitely off the deep end. But I can switch from 24 to 48V with just a few cable and fuse changes. It helps that I have a local Victron dealer that I can actually walk in and talk to and get parts and supplies, usually the same day.

I've been watching Victron installation videos on You-Tube and combing the forums as I try to get my mind around an all Victron installation in my setting. What I see is that most of Victron charge controllers seem focused on the mobile market and all lack provisions for conduit which makes for some awkward installations for those trying to meet at least the spirit of North American code in their installations. I was looking at both the Victron VE-panel and the Midnite e-panel available at Current Connected and neither offer a method for mounting a Victron charge controller directly to the box I think because of the design limitations of the charge controllers. As noted on some of the forums, a range of conduit-capable, fan-cooled charge controllers would help address this.

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You may want to consider the rs450/100 and 200 SCCs, should work fine with conduit. Fan cooled, PV is isolated from the battery, two or four trackers, few other niceties.

sunshine_eggo said:

Ah... Well, they're spendy as shit, but the RS450/100 or /200 address your concerns.

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I did my part with 450/100 but Victron stubbornly kept their pricing the same.

glandpuck said:

....the onboard charger does not directly communicate with lithium batteries. But it will charge them just fine....

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That was my beef with Outback, because of their affiliation with Enersys they did not open their communication protocol to other batteries or BMSs. Clearly any configurable charger will charge just fine. To me there is value in closed communications between inverter and battery.

Brucey said:

I did my part with 450/100 but Victron stubbornly kept their pricing the same.

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Remember the parallel and serial ports on personal computers? Then some persons came up with USB plug and play communications and the old ports went by the wayside. Remember Sony Betamax? They wanted to keep it closed to themselves. So VHS was invented and used by all the competitors and eventually Sony had to switch to VHS too.

Closed loop for lithium battery banks is wonderful, a great time saver and requires little to no hardware knowledge.

Thanks everyone for the responses. I will put your ideas in my decision hopper. If Brucey would just buy a few more 450/100s, I might be able to justify one.