Do you think this BMS has over- and undervoltage protection?

Maniac_Powerwall

Maniac_Powerwall

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Could anyone who is firm to pcbs give me information about this BMS? This is a tool battery BMS board. Do you think it has over and undervoltage protection? Current protection, I only see a fuse 40 amps!? Or just balancing? Would you trust that BMS in either way? Do you think I can charge or discharge that one safely?


image_vdidsw.jpg
 
I would not trust it since you dont know anything about it
 
I dont know anything about so i Will say no. I never use a bms that dont know anything about.

You havent told is where it comes from of you know anything about it
 
It depends on what you're thinking of doing with this board.
If you're just wanting to understand it or rebuild a tool, that's great.
If you're wanting to use it for a powerwall, then daromer is right: get a new one that you know the full details for.

It would help if you could show the other side of the PCB.
From a look at the side you've posted, it's complexity & # of interconnects suggests it is doing per cell monitoring.
Most power tool ones of any complexity do have low voltage & over current cutouts.
For pack over voltage, they might rely on the charger?
If you're luck it'll do some balancing too but I can't see balancing resistors on this one.
Bottom left 3 in a row are the current sense resistors, so it's doing over current.
Hopefully the other side has some decent MOSFETs to cut-off, etc
 
It's mounted so i could have only a short view. I'll send picture of the other side later. But I think it is empty :-(
 
Redpacket said:
It depends on what you're thinking of doing with this board.
If you're just wanting to understand it or rebuild a tool, that's great.
If you're wanting to use it for a powerwall, then daromer is right: get a new one that you know the full details for.

It would help if you could show the other side of the PCB.
From a look at the side you've posted, it's complexity & # of interconnects suggests it is doing per cell monitoring.
Most power tool ones of any complexity do have low voltage & over current cutouts.
For pack over voltage, they might rely on the charger?
If you're luck it'll do some balancing too but I can't see balancing resistors on this one.
Bottom left 3 in a row are the current sense resistors, so it's doing over current.
Hopefully the other side has some decent MOSFETs to cut-off, etc
Click to expand...

No, nothing on the other side. Think they use the 'ID' pin to give information to the charger or tool for voltage protection. And maybe only balancing while charging in cooperation with the charger maybe lowering charging current or similar. Think I need to wire them to a BMS doing what I want. Not sure if for powerwall or mobile power supply maybe. I'll see...
 
What are you trying to do and why?

Where does this board come from?
 
It's a tool battery. Still complete. Got 20 of them brand new, very good price. With Sony VTC5 2600 mAh 14S Pack. Thought it would be funny to hang 20 to the wall in parallel and use them as a part of the powerwall. Hoping they have everthing in them what they need. I got some wich have balancing and everything on their BMS. Opening these made me wonder. No MOSFETs big enough to handle the current. Only big fuse. Now I think about what to do with these :)
 
No they dont have disconnect in Them. Most of the tools have the lvdc in the Tool itself. You can of course build a powerwall like that but you Still lack overview and proper disconnect.

Use Them as is or rebuild. Fiddle in the middle is not something i would do unless you got tons of time to spare
 
The on/off low volts cut out might have been done by other components near the tool finger control switch, eg variable speed circuit, etc, might have got an enable/disable line from this board?
 
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