Well this happened! What is happening? Help!
- Thread starter Nef003
- Start date
ksmithaz1
Solar / EV Junkie
The pyrotechnics seems odd in general. Per other comments I would test the voltage and polarity and turn on each independently. My guess would be one or more of the units was damaged in shipping, possibly due to a poor internal design flaw.
robbob2112
Doing more research, mosty harmless
My guess is the positive lead had a nut fall off and it is just touching the inside of the case. When it is turned on the sparks are caused by the dead short.
rodrick
Free energy enthusiast
According to the OP he turn all of them on before he paralleled them and there were no problems only after connecting them in parallel did the issues arise
That really fits the positive and negative terminals being labeled wrong.
I would disconnect all of them and power each up and check voltage polarity at the terminals. I bet the 2nd from the bottom is wired backwards inside from the factory.
Bill Young
Engineer from ECO-WORTHY
This looks like a short somewhere, I will assist you in getting after sales support as soon as possible!
ksmithaz1
Solar / EV Junkie
I'm not sure how you would do that on an assembly line, this I find this idea somewhat doubtful, but I would never say never. Since I'm not there fondling it myself, ... The odd behavior if truly only when connected in parallel doesn't make a ton of sense electrically. /i'm just skeptical by nature, but what would create a backfeed type spark like that? The power switch is a soft switch that engages a relay, this is just a bizarre occurrence, I could only fathom some sort of damage to the BMS board that would cause it. I think we do not have enough good information on the whole thing.
robbob2112
Doing more research, mosty harmless
Maybe it is positive shorted to case and when powered before it had nowhere to go. I.e. sitting by itself. But once in a rack the circuit was completed by the case in the rack.
ScrotpusGobbleBottom
Cannibalism starts with a kiss.
We sure dont have much!
ksmithaz1
Solar / EV Junkie
I'm sure these guys don't do a ton of QA, but I would find it unlikely they don't turn the unit on and run a simple quick voltage and load test before they box it. Thus I would guess, barring some shenanigans, something got disturbed in shipping. I would find a more likely failure scenario to be a crappy battery dies in the unit or an open, or relay failure, or a popping breaker, or ... Sparks flying everywhere is just really odd.
Fisherguy66
I never thought I'd curse at clouds so much!
Yea if it was a $50 batt there would be no debate about opening it up but these aren't cheap
rodrick
Free energy enthusiast
Please post the cause of the failure when known we are a bunch of curious individuals all trying desperately to get the right answer
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OffGridForGood
Catch, make or grow everything you can.
except I think I was mistaken - the battery on their site with the Red pos on left isn't a server rack pack, just a case battery.
crossy
Solar Wizard
Wow that was fun! 
I'm with the others.
COMPLETELY disconnect each pack and test for output voltage and polarity. Also check that there's no connection between either terminal and the metalwork.
I'm with the others.
COMPLETELY disconnect each pack and test for output voltage and polarity. Also check that there's no connection between either terminal and the metalwork.
How are the lugs connected to the terminal?
It looks like the lugs are 'reversed', thus facing down. That leaves only a very minimal gap between the lug and the 4 screws which hold the terminal itself Maybe even only insulated by the heatshrink and/or a very tiny gap.
Altough the video isn't very clear, it looks like the point of origin of the spark is one of the screws holding the terminal to the casde... if the positive also has this (or on any other battery) that basicly makes the whole stack/cases positive... (even with the BMS off since the BMS only controls the negative)
Switching on a BMS will instant create a short between the chassis and the lug of the powered-on battery in that case.....
Measure to see if there is any connection between positive and the chassis.
It looks like the lugs are 'reversed', thus facing down. That leaves only a very minimal gap between the lug and the 4 screws which hold the terminal itself Maybe even only insulated by the heatshrink and/or a very tiny gap.
Altough the video isn't very clear, it looks like the point of origin of the spark is one of the screws holding the terminal to the casde... if the positive also has this (or on any other battery) that basicly makes the whole stack/cases positive... (even with the BMS off since the BMS only controls the negative)
Switching on a BMS will instant create a short between the chassis and the lug of the powered-on battery in that case.....
Measure to see if there is any connection between positive and the chassis.
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crossy
Solar Wizard
There should be a nice visible "splat" mark if that's the case.
The negative and positive screws securing the terminals are bonded. Just tested it on mine. Connect straight to the case. Very common configuration
Texas-Mark
Solar Wizard
- Joined
- Aug 4, 2021
- Messages
- 1,879
I think that picture is deceiving. You can see that the area the lug connects to is raised quite a bit (looking at the left side). I think there is a much bigger gap than camera illusion portrays.
Drunkin Solar
Solar Enthusiast
Seplos Mason has positive terminal on the right. Negative to the left of it.
jeff.lankford
Solar Enthusiast
Actually, on the Seplos website they show Mason product photos where the red terminals are randomly on the left or on the right, depending on the Mason capacity size. But in all cases, the terminals on the left are positive and on the right are negative, i.e. on some products they appear to be using red terminals as negative and black terminals as positive, with no consistency. Why would they do that?
Quattrohead
Emperor Of Solar
No way they have mixed the terminals. Placement is one thing, using red/black backwards ridiculous.......isn't it ???
jeff.lankford
Solar Enthusiast
I agree it's hard to believe. At best, they have just made mistakes on their webpage photos.
It almost looks like that's not a real photo and the "P+" and "P-" labels were just added in Photoshop, but when you see this same thing from a different angle it does seem like they're legitimate photos. Did they just assemble the battery wrong for the photoshoot? Not sure after that how to trust a company that could make such a blatant mistake on something so simple...
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