We added solar well over a decade ago, and installed the first grid-tied, battery-backed-up (is the term Hybrid?) system in our city. About a year ago all of our Trojan 6v batteries all finally died. So I did the battery internet deep dive and ended up with two SOK 48V 100Ah Server Rack LiFePO4 Batteries, with plans to add more later. Then life got crazy and money got tight and the batteries have been sitting in my garage for over a year. But I'm now ready to move forward.
The original solar installers are long gone, but they installed a Xantrex (Schneider) 6048 Inverter and an Outback Charge controller. These two devices don't actually talk to each other (other than through voltages), which I think is less than ideal, but it's what they installed. The installation was pretty complex, including an outside shutoff that was required by the city at the time. I don't pretend to fully understand how it's wired. But I do understand the fundamentals.
My system has been down for over a year while I find the time and money to finish getting the new batteries installed. I was surprised to discover that my solar panel system can't work without batteries. I figured they were an add-on for when the grid goes down, but apparently, they are wired in such a way that without them nothing works. My bills have been higher.
My hope is that I can pretty much just swap out the Trojans for the two SOK Batteries (in parallel of course), reprogram the Outback to be a little more in line with the charging needs of LiFPO chemistry (it doesn't actually have any lithium battery modes, but I understand you can fake the settings pretty well). And turn it all back on. I've seen reports of similar setups that seemed to transition to LifPO rack batteries pretty smoothly. But those systems all seem to be pure off-grid. Where I get fuzzy and a bit nervous is how grid-tie plays into this. It is obviously already all wired for this, and I don't plan to touch anything on the AC side.
I do plan to put in an inverter pre-charge circuit (or probably just a 48v light bulb) button. Something like this: (
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Some questions:
1) How drop-in replacement is this likely to be?
2) Do I need battery fuse(s)? I see these in all the rack system setup videos, but my lead-acid previous system didn't have any. I'm inclined to just for safety. But I'm reticent to mess with any more wiring than needed. I also seem to see a lot of bus bars in use in these videos, but since I'm drop-replacing, I don't see the need unless I'm missing something.
3) Does grid-tying change anything about how these rack-batteries behave?
4) Does anybody know the settings I should change on the Outback Flexmax (circa 2012-ish) to make it more lithium friendly?
5) What are the odds, SOK (or Current Unlimited) can get the Xantrex, Outback and batteries all talking on some kind of common language XAN/CAN/bus?
6) Not knowing the charge state of the SOKs, should I invest in a 48v stand-alone charger just to get them charged back up before the install? I haven't even tried turning them on in a year, so I don't know how dead they are.
7) I don't really have the budget, but should I just sell the Outback and get a charge controller that's more lithium aware? The Outback has been a workhorse and I'd rather not replace it. But, then again if I get a Schneider charge controller (MPPT 60 PV?), then I would assume they'd be able to finally have proper comms.
8) What also don't I know, that I probably should?
9) I can probably scrape a budget for an in-person consultation if anyone knows an installer in Utah who would be comfortable with a system like this. Or I'd be open to a virtual consultation if anyone is offering.
10) Thank you for reading this far!
The original solar installers are long gone, but they installed a Xantrex (Schneider) 6048 Inverter and an Outback Charge controller. These two devices don't actually talk to each other (other than through voltages), which I think is less than ideal, but it's what they installed. The installation was pretty complex, including an outside shutoff that was required by the city at the time. I don't pretend to fully understand how it's wired. But I do understand the fundamentals.
My system has been down for over a year while I find the time and money to finish getting the new batteries installed. I was surprised to discover that my solar panel system can't work without batteries. I figured they were an add-on for when the grid goes down, but apparently, they are wired in such a way that without them nothing works. My bills have been higher.
My hope is that I can pretty much just swap out the Trojans for the two SOK Batteries (in parallel of course), reprogram the Outback to be a little more in line with the charging needs of LiFPO chemistry (it doesn't actually have any lithium battery modes, but I understand you can fake the settings pretty well). And turn it all back on. I've seen reports of similar setups that seemed to transition to LifPO rack batteries pretty smoothly. But those systems all seem to be pure off-grid. Where I get fuzzy and a bit nervous is how grid-tie plays into this. It is obviously already all wired for this, and I don't plan to touch anything on the AC side.
I do plan to put in an inverter pre-charge circuit (or probably just a 48v light bulb) button. Something like this: (
Some questions:
1) How drop-in replacement is this likely to be?
2) Do I need battery fuse(s)? I see these in all the rack system setup videos, but my lead-acid previous system didn't have any. I'm inclined to just for safety. But I'm reticent to mess with any more wiring than needed. I also seem to see a lot of bus bars in use in these videos, but since I'm drop-replacing, I don't see the need unless I'm missing something.
3) Does grid-tying change anything about how these rack-batteries behave?
4) Does anybody know the settings I should change on the Outback Flexmax (circa 2012-ish) to make it more lithium friendly?
5) What are the odds, SOK (or Current Unlimited) can get the Xantrex, Outback and batteries all talking on some kind of common language XAN/CAN/bus?
6) Not knowing the charge state of the SOKs, should I invest in a 48v stand-alone charger just to get them charged back up before the install? I haven't even tried turning them on in a year, so I don't know how dead they are.
7) I don't really have the budget, but should I just sell the Outback and get a charge controller that's more lithium aware? The Outback has been a workhorse and I'd rather not replace it. But, then again if I get a Schneider charge controller (MPPT 60 PV?), then I would assume they'd be able to finally have proper comms.
8) What also don't I know, that I probably should?
9) I can probably scrape a budget for an in-person consultation if anyone knows an installer in Utah who would be comfortable with a system like this. Or I'd be open to a virtual consultation if anyone is offering.
10) Thank you for reading this far!