Nkon 16S/100Ah Used Packs- 380 euros

[Nightguest]

Nkon have a bunch of 16S 100Ah used packs on sale for 380 euros (I paid an extra 60e for shipping to Netherlands).

• Used, but according to their testing has at least 96% capacity
• Heater band included, but it runs on 220V (whyyyy)
• No BMS.
• Unbranded, so no info on what it was used for before.

51.2V 5kWh 16S 100ah LiFePO4 Batterijpakket - Gebruikt - Prismatisch - LiFePO4 - Oplaadbare batterijen | NKON

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www.nkon.nl

*I have purchased one for myself so when it arrives I'll be more than happy to share photos, cell tests, etc.

 

[boomer286]

Hello, are the cells welded? how to change them when there is one that needs to be changed?
TIG?

 

[Nightguest]

Hello, are the cells welded? how to change them when there is one that needs to be changed?
TIG?

No idea, but I have ordered one for myself, as for me it doesn't matter either way.

So, when it arrives, I'll take a bunch of photos and share them here!

 

[DJSmiley]

Thanks for mentioning this, hadn't seen those before. Ordered as well.

I was thinking about pickup, but I think they are gone pretty soon and I don't have time during their opening hours to pickup. (Its a 1,5 hour drive for me, 3 incl return)

 

[DJSmiley]

Did some further googling and it looks like they are (or at least are pretty similar) to Sofar BTS 5K modules.

SOFAR - Batterie BTS 5K - Batteries solaires - Powr Connect

Batterie BTS 5K - module de batterie 5.12kWh

powr-connect.shop

https://reps.fi/wp-content/uploads/2024/04/Sofar-BTS-5K_User-Manual_2023-03-10_V1-0_en-EU.pdf

Also the label on the images on Nkon matches the label listed in the documentation:






It looks like the box did include some stepup/stepdown circuits, since the manual lists 350-435V DC, but the internal pictures (and partno) refer to a 16S configuration. Think the covers and internal electronics are removed, only leaving the cells.

On some pictures of these units it does look like there is a heatsink as well, so that would make sense if it has to convert to/from HV

That also would explain the usage of MC4 connectors: With high voltage DC (thus low current) it makes perfect sense.

But based on the images/available space, and by the looks prewired cell leads, it looks pretty easy to install a BMS and fuse inside the unit.

 

[Nightguest]

Mine has arrived, so here are a few photos of it!

The case (opened up).
To open it up, you'll need a TX30/pin driver bit and a PH2 as well.
Once you're inside, to get the rails off you'll need a PH3.


Getting that black insulation sheet off is a bit annoying as it is clipped in place on the sides, as well as glued on top of the cells. A bit of force and it comes off (it did not break for me, which is nice).

Looking at the cells, they don't have studs, they're welded in place (you can take the pack out of the larger metal case, but I've not done that yet).
The temperature sensors are below the yellow taps and seem to be held in with foam (confusing decision), and the balance leads seem to be glued into place with something that is softish.



The cells do have QR codes but, I've not been able to get to them yet. They're below the black plate and the temperature sensors are on top of them. I'll take it all apart later on and will see what they are later on.

@DJSmiley was correct that this is the Sofar BTS 5K, which explains all the other electrics. I won't be using them so I'll take them out later on.

 

[DJSmiley]

Mine will arrive on thursday (hopefully).

Any particular reason why you wanted the black insulation to come off (apart from curiousity)?

Based on the Nkon images (and the images you're showing) it looks all cells already contain a BMS wire so it's just a matter of rewiring them to a new BMS and connect the main power leads.

I've also ordered some small JBD BMSses, will see how they work and keep the balance (or not). Might upgrade to a more decent BMS (with active balancing and CAN) but for now, it's just to play so a 100A BMS is fine (I have ordered 3 sets, and only have a MP 3000VA so plenty for now)

 

[Nightguest]

Any particular reason why you wanted the black insulation to come off (apart from curiousity)?

I wanted to check if the cells were welded or not.
If they were not, I'd have taken them out and put the cells on a shelf (limited space for me), and then I'd use the case for something else.
I also wanted to test each cell individually to see what the capacity of each one was, however...that's a little harder here.

Based on the Nkon images (and the images you're showing) it looks all cells already contain a BMS wire so it's just a matter of rewiring them to a new BMS and connect the main power leads.

Yeah, there are 4 temperature sensors, each with 2 wires, and then the 16 balance leads.
*Took a photo of the BMS wire connectors, annoyingly the connectors for each group of wires are slightly different.

I will most likely need to redo the connector side for those wires so that they fit in the BMS.

*Sorry for the crap photo, for some reason my phone refused to focus.