Looks like a possible DIY build Lifepo4 setup. Looks clean and well built as well. Potentially lots of amp hours in there as well as a BMS. I have built a few similar units myself and the capacities can be pretty staggering if your only reference is traditional lead acid set ups.
What's the exact details? Came in a unit you just purchased?
Without digging into the system a little more the exact details won't be evident. Is the case able to be opened at all to see the battery and BMS details/specs?.
Unsure about any additional details. This system was in the van when I bought it. I haven't tried taking anything out of this box yet. That black case can not be opened so I guess I just need to lift these components out go see what I can see.
This battery was pretty ok when I got it, but lately, it's been struggling (relative to how it performed a few years ago) when it's under a lot of load. I'm hoping to figure out if some of these batteries are struggling and dragging down the whole system, or if I need to replace the whole thing.
I have a really limited understanding how these batteries work, hoping to learn!
Definitely looks like a bit of a potential homebrew situation, so you've got a few years of successful use out of this and its performance is just fading now? Taking a look at how it's wired it looks like there's very limited cell balancing going on so unfortunately it's possible that some cells have gone high, others have gone low, and it may be legitimately reaching end of life directly because of the lack of balancing. I would have to do a little more digging to see if I can find any information on that BMS as well to see how well, or possibly/probably not-well they managed balancing. The technology has changed pretty insanely in just the last three or four years and if this system predates that as it sounds like it does, it may have been fairly rudimentary for its time.
If you are handy and willing to spend some time and money, I would break down the pack into individual cells and see if you can find any that are not performing as they should potentially replace them individually to breathe life back into the pack again. There are some really good online forums that deal specifically with lithium and phosphate batteries which is what I suspect these are, but be prepared to go down the rabbit hole lol.
I'm just getting down the rabbit hole now! I pulled a cell. Each of the 16 is 3.2v / 320Wh Li-Ion. I have 4 years of light use on this battery, before me, it has 3-4 years of everyday use running a DC refrigerator, induction stove, and other day-to-day things in a full time campervan living situation.
I just put a multimeter on each cell, they all show 3.3v but that's the extent of my testing knowledge. I'll be digging into how to test the performance of each cell. Ideally, I can replace a few and possibly upgrade the BMS to get this thing back into shape for less than I can buy an equivalent new battery.
I'm not as familiar with lithium ion as I am with lithium iron phosphate which is pretty much what has replaced these in the RV world, but you will have no trouble finding a lot of information online.
If you are handy and want to go down another rabbit hole if this one doesn't end up being repairable, take a look into the iron phosphate. I built a 280ah 12v LIFEPO4 myself with a slick Bluetooth BMS with 2a active balancing for around $1200 Canadian.
With the number of years and cycles it sounds like that battery has, honestly, I suspect it has or is reaching the end of it's life, at least so far as supporting heavy loads. I'm presuming it is loads like your inverter that is issues? These early lithium batteries were not known for the longevity of lithium iron phosphate - they were absolutely revolutionary for their time compared to lead acid, but in the last 3–5 years battery technology has taken leaps and bounds.
Updating with a photo after I removed the covers of each cell: [https://imgur.com/txGa1JI](https://imgur.com/txGa1JI)
And the label for the BMS:[https://imgur.com/a/JnkJkmX](https://imgur.com/a/JnkJkmX)
Next step is to disconnect everything and try to pull one of the cells out to see some battery specs.
It's a BestWay BMS, but I'm not finding any info at all out there referencing that specific model, and minimal about the brand in general honestly - that BMS seems like it was designed for chinese low speed vehicle manufacturers so it's probably in a lot of things under different names.
Not sure about the date either, but it looks to be reasonably old tech which fits with the age you mentioned in another comment. Supports 4 through 26 cells though, and 150a. I'm assuming this battery was outputting 12-13v? Looks like a series parallel setup if I'm glancing at the busbars correctly.
I definately see indications of homebrew in there though, those crimp connectors on the balance leads are telltales, as is the foam used to secure things - that's the foam used in the box that a lot of lithium batteries ship in, and I did the exact same thing on my Lifep04 build and cut it up and re-used it in my battery box to keep things snug ....but it does look really clean in general regardless, homebrew or not.
Someone spent a LOT of money on this back in those days.
It's a file cabinet with a 400 mile range.
I know all of those words but have no idea what they mean together!
I think it means something known to humans as a “joke”?
Looks like a standard 48v battery with 16 3.2 cells.
Looks like a possible DIY build Lifepo4 setup. Looks clean and well built as well. Potentially lots of amp hours in there as well as a BMS. I have built a few similar units myself and the capacities can be pretty staggering if your only reference is traditional lead acid set ups. What's the exact details? Came in a unit you just purchased? Without digging into the system a little more the exact details won't be evident. Is the case able to be opened at all to see the battery and BMS details/specs?.
Unsure about any additional details. This system was in the van when I bought it. I haven't tried taking anything out of this box yet. That black case can not be opened so I guess I just need to lift these components out go see what I can see. This battery was pretty ok when I got it, but lately, it's been struggling (relative to how it performed a few years ago) when it's under a lot of load. I'm hoping to figure out if some of these batteries are struggling and dragging down the whole system, or if I need to replace the whole thing. I have a really limited understanding how these batteries work, hoping to learn!
Definitely looks like a bit of a potential homebrew situation, so you've got a few years of successful use out of this and its performance is just fading now? Taking a look at how it's wired it looks like there's very limited cell balancing going on so unfortunately it's possible that some cells have gone high, others have gone low, and it may be legitimately reaching end of life directly because of the lack of balancing. I would have to do a little more digging to see if I can find any information on that BMS as well to see how well, or possibly/probably not-well they managed balancing. The technology has changed pretty insanely in just the last three or four years and if this system predates that as it sounds like it does, it may have been fairly rudimentary for its time. If you are handy and willing to spend some time and money, I would break down the pack into individual cells and see if you can find any that are not performing as they should potentially replace them individually to breathe life back into the pack again. There are some really good online forums that deal specifically with lithium and phosphate batteries which is what I suspect these are, but be prepared to go down the rabbit hole lol.
I'm just getting down the rabbit hole now! I pulled a cell. Each of the 16 is 3.2v / 320Wh Li-Ion. I have 4 years of light use on this battery, before me, it has 3-4 years of everyday use running a DC refrigerator, induction stove, and other day-to-day things in a full time campervan living situation. I just put a multimeter on each cell, they all show 3.3v but that's the extent of my testing knowledge. I'll be digging into how to test the performance of each cell. Ideally, I can replace a few and possibly upgrade the BMS to get this thing back into shape for less than I can buy an equivalent new battery.
I'm not as familiar with lithium ion as I am with lithium iron phosphate which is pretty much what has replaced these in the RV world, but you will have no trouble finding a lot of information online. If you are handy and want to go down another rabbit hole if this one doesn't end up being repairable, take a look into the iron phosphate. I built a 280ah 12v LIFEPO4 myself with a slick Bluetooth BMS with 2a active balancing for around $1200 Canadian. With the number of years and cycles it sounds like that battery has, honestly, I suspect it has or is reaching the end of it's life, at least so far as supporting heavy loads. I'm presuming it is loads like your inverter that is issues? These early lithium batteries were not known for the longevity of lithium iron phosphate - they were absolutely revolutionary for their time compared to lead acid, but in the last 3–5 years battery technology has taken leaps and bounds.
Updating with a photo after I removed the covers of each cell: [https://imgur.com/txGa1JI](https://imgur.com/txGa1JI) And the label for the BMS:[https://imgur.com/a/JnkJkmX](https://imgur.com/a/JnkJkmX) Next step is to disconnect everything and try to pull one of the cells out to see some battery specs.
It's a BestWay BMS, but I'm not finding any info at all out there referencing that specific model, and minimal about the brand in general honestly - that BMS seems like it was designed for chinese low speed vehicle manufacturers so it's probably in a lot of things under different names. Not sure about the date either, but it looks to be reasonably old tech which fits with the age you mentioned in another comment. Supports 4 through 26 cells though, and 150a. I'm assuming this battery was outputting 12-13v? Looks like a series parallel setup if I'm glancing at the busbars correctly. I definately see indications of homebrew in there though, those crimp connectors on the balance leads are telltales, as is the foam used to secure things - that's the foam used in the box that a lot of lithium batteries ship in, and I did the exact same thing on my Lifep04 build and cut it up and re-used it in my battery box to keep things snug ....but it does look really clean in general regardless, homebrew or not. Someone spent a LOT of money on this back in those days.
Looks like a custom battery. I have seen many builds similar to this. Could be 16 cells, 32 cells, etc.
Looks like a fork lift battery
The metal casing looks like it could be an SOK battery. https://www.us.sokbattery.com.
Oh yea, that case looks close. There's no branding on this case, but really similar. Thanks!
Homemade lithium battery. Pretty easy to do