48V Overkill BMS issues - fake test slip?

[suchys]

I might need some feedback. I finally went to install 16S (48V) overkill solar BMS, but then a swarm of issues came:

• One balance lead was missing BC12 on drawing. I found the same connector with wire at home and inserted it into the connector (which had a slot covered in white silicone, so far wire was never there).
• Tripple checked everything - voltages were correct
• Inserted balance connector into BMS - one wire went up in smoke
• Contacted support, not much useful information, except to open the BMS and look at the resistors
• Even before I opened BMS I saw what the problem was: the BMS is apparently 20S one, and some pins were shortened by solder bridges, including a bridge spanning from BC12 to BC13, shorting the cell (on the board it is BC17,18, and 19)
• Contacted support. Look at resistors (resistors are looking brand new, and measure brand new, no problem here)
• Removed bridge between BC17 and 18, yet the BMS would not work.

Does anyone have a picture of the board where the balance wires are connected?
Conclusion: while the BMS came with a check slip, it was apparently never checked - it must be a fake - as long as should the BMS be inserted into a regular harness and battery, the harness would go in smoke instantly. Bad cable, bad BMS, support sounds like a guy is reading from a Chinese manual while can't speak Chinese, so he's using Google translate. Almost like Will's communication with some far east companies, except you get all this at the premium US $$$.
Given how complex the assembly of BMS is - it is for ham radio on the road, so far it needs to be vibration resistant, so it would take a week to rebuild it all...
--Petr

 

[Nobodybusiness]

I might need some feedback. I finally went to install 16S (48V) overkill solar BMS, but then a swarm of issues came:

• One balance lead was missing BC12 on drawing. I found the same connector with wire at home and inserted it into the connector (which had a slot covered in white silicone, so far wire was never there).
• Tripple checked everything - voltages were correct
• Inserted balance connector into BMS - one wire went up in smoke
• Contacted support, not much useful information, except to open the BMS and look at the resistors
• Even before I opened BMS I saw what the problem was: the BMS is apparently 20S one, and some pins were shortened by solder bridges, including a bridge spanning from BC12 to BC13, shorting the cell (on the board it is BC17,18, and 19)
• Contacted support. Look at resistors (resistors are looking brand new, and measure brand new, no problem here)
• Removed bridge between BC17 and 18, yet the BMS would not work.

Does anyone have a picture of the board where the balance wires are connected?
Conclusion: while the BMS came with a check slip, it was apparently never checked - it must be a fake - as long as should the BMS be inserted into a regular harness and battery, the harness would go in smoke instantly. Bad cable, bad BMS, support sounds like a guy is reading from a Chinese manual while can't speak Chinese, so he's using Google translate. Almost like Will's communication with some far east companies, except you get all this at the premium US $$$.
Given how complex the assembly of BMS is - it is for ham radio on the road, so far it needs to be vibration resistant, so it would take a week to rebuild it all...
--Petr

Im not sure what you are seeing but this is one of mine.

The only reason a wire would do that is usually because it’s in the wrong order.

IE It went from 3v to 9v.

Regardless Overkill says they will replace it no matter what caused it to go boom.

 

[suchys]

Tha

Im not sure what you are seeing but this is one of mine.

The only reason a wire would do that is usually because it’s in the wrong order.

IE It went from 3v to 9v.

Regardless Overkill says they will replace it no matter what caused it to go boom.

Thanks, that's not enough. Attaching a picture with BMS opened to understand the problem. BC22-24 connected together - makes perfect sense, BC17-19 connected together makes no sense, it also means the BMS could not have ever worked or be tested.

 

[suchys]

Im not sure what you are seeing but this is one of mine.

The only reason a wire would do that is usually because it’s in the wrong order.

IE It went from 3v to 9v.

Regardless Overkill says they will replace it no matter what caused it to go boom.

Also my checklist before connecting the cables so far.

 

[Nobodybusiness]

Also my checklist before connecting the cables so far.View attachment 91662

The checklist that comes with these is a computer printout not handwritten.

Did you buy this from overkill or a distributor?

Looks like someone tried to modify a 20s into a 16s.

If you bought from Overkill then they will replace it.

If from a distributor then not sure what your chances are.

Does it have the overkill sticker on it?

 

[suchys]

The checklist that comes with these is a computer printout not handwritten.

Did you buy this from overkill or a distributor?

Looks like someone tried to modify a 20s into a 16s.

If you bought from Overkill then they will replace it.

If from a distributor then not sure what your chances are.

Does it have the overkill sticker on it?

I bought from Overkill, but it does not change the reality that the slip couldn't have been generated with this BMS - it would put their harness on fire instantly. I really "love" they will replace it. About the same work to put a Daly inside, it has been heavily embedded into the system. I'd rather prefer to get a proper, not a fake product.

 

[400bird]

View attachment 91659

When comparing your pic to Baisjo's, it looks to me like your connector is pinned out incorrect. Like the center 3 wires should all be one pin to the left. Then you wouldn't have the short between 17 and 19, because you wouldn't have a wire in 19.

Also, if they do bench test these, it's probably with a bench harness. And they aren't testing the supplies harnesses.

Also, and I think more importantly, I'm pretty sure every BMS manufacturer requires fused BMS leads. If yours were fused, you wouldn't have smoked the wiring.

 

[suchys]

When comparing your pic to Baisjo's, it looks to me like your connector is pinned out incorrect. Like the center 3 wires should all be one pin to the left. Then you wouldn't have the short between 17 and 19, because you wouldn't have a wire in 19.

Also, if they do bench test these, it's probably with a bench harness. And they aren't testing the supplies harnesses.

Also, and I think more importantly, I'm pretty sure every BMS manufacturer requires fused BMS leads. If yours were fused, you wouldn't have smoked the wiring.

Good catch, you are right, they sent me a completely f**** up harness seems to me! One wire missing, the others at the wrong positions. Frankly, I've never heard about fused BMS leads (except that the board would have the polyfuses, etc.)

 

[SparkyJJO]

Fused BMS leads? Never heard that. I have not seen it on here either, though it does make sense.

 

[Nobodybusiness]

I bought from Overkill, but it does not change the reality that the slip couldn't have been generated with this BMS - it would put their harness on fire instantly. I really "love" they will replace it. About the same work to put a Daly inside, it has been heavily embedded into the system. I'd rather prefer to get a proper, not a

Fused BMS leads? Never heard that. I have not seen it on here either, though it does make sense.

They are supposed to be fused but most don’t do it.

 

[suchys]

When comparing your pic to Baisjo's, it looks to me like your connector is pinned out incorrect. Like the center 3 wires should all be one pin to the left. Then you wouldn't have the short between 17 and 19, because you wouldn't have a wire in 19.

Also, if they do bench test these, it's probably with a bench harness. And they aren't testing the supplies harnesses.

Also, and I think more importantly, I'm pretty sure every BMS manufacturer requires fused BMS leads. If yours were fused, you wouldn't have smoked the wiring.

So far that was it, good catch. Removed white silicone, repinned wires, put a new silicone and the BMS is running now. So far so good, except for the quality assurance and communication with Overkill, not any different from talking to a company overseas. Let's let the silicone dry up, charge it up and run some tests later.

 

[Nobodybusiness]

So far that was it, good catch. Removed white silicone, repinned wires, put a new silicone and the BMS is running now. So far so good, except for the quality assurance and communication with Overkill, not any different from talking to a company overseas. Let's let the silicone dry up, charge it up and run some tests later.

Probably burned out one channel but you're right.
Cant be too sure about it now...
Hopefully it works for you or perhaps you could get it replaced.

I have Overkill, JBD, Daly.

I have thought about changing them all to the Batrium Watchmon Core and K9.

 

[suchys]

Probably burned out one channel but you're right.
Cant be too sure about it now...
Hopefully it works for you or perhaps you could get it replaced.

I have Overkill, JBD, Daly.

I have thought about changing them all to the Batrium Watchmon Core and K9.

It works, there's no a strong reason for burned channel fortunately. Never saw an overvoltage or negative voltage due to swapped wires. Thanks for hints.

 

[Nobodybusiness]

It works, there's no a strong reason for burned channel fortunately. Never saw an overvoltage or negative voltage due to swapped wires. Thanks for hints.

Sounds good. Good Luck with that...

 

[suchys]

Sounds good. Good Luck with that...

I will certainly need it. Thanks

 

[rhino]

Fused BMS leads? Never heard that. I have not seen it on here either, though it does make sense.

Batrium strongly emphasizes this and has pictures to make sure you get the point

 

[740GLE]

Small gauge wire of BMS leads is what 32/40 gauge? I’m sure many get away with melting the conductor vs the added expense/connections of fuses.

Not saying that’s the best method, but with any electrical connection between a cell voltage and ground has the potential to see 100s of amps, eventually everything is a fuse.

Andy at off grid garage uses fuses for his sensing leads, but his set up also makes it easy to hot swap BMS.

 

[RobertGreen]

Small gauge wire of BMS leads is what 32/40 gauge? I’m sure many get away with melting the conductor vs the added expense/connections of fuses.

Not saying that’s the best method, but with any electrical connection between a cell voltage and ground has the potential to see 100s of amps, eventually everything is a fuse.

Andy at off grid garage uses fuses for his sensing leads, but his set up also makes it easy to hot swap BMS.

I've got a couple of JBD mosfet based BMS here, one from Overkill, one from RadioBTech and they both have 24 awg wire for the sense leads.

I've seen people use fuses on the sense leads before, but IMO the ideal place to locate the fuses would be as close to the attachment point at the battery terminal as possible. I would think that a likely culprit for one of these wires being shorted would be getting pinched or pulled as the bus bars and nuts etc get assembled across the tops of the batteries, and a fuse on the BMS board for each lead wouldn't really help with that at all.

Of course, adding a small (1-3 amp) fuse would add resistance to the lead, which wouldn't probably matter in terms of affecting the sensing voltage, but might matter if you're using an active balancer with 1+ amps balance current.

 

[Bluedog225]

I was under the impression that the overkill guy was local (in the US). No?

First bad thing I have heard about them.

If it’s jacked up, and they will replace it, seem fair.

Does overkill hang out here?

 

[HRTKD]

Does overkill hang out here?

He used to. He's so busy (due to incredible success) that I doubt he has time to address issues here.