P group voltage drop more than other p groups

[glyphiks]

@LexHoja

new wheels bringing more vibrations

Ehhhh potentially?

It could be any number of things, but by the looks of it, it’s probably going to be pretty tricky to diagnose.

The entire pack will need to come out and given the way it was constructed, it’s not gonna be especially easy or safe to repair.

I’m placing bets on a cell shorting on the carbon

Edit:

@Schtekarsten

Thanks for the reply! I appreciate the feedback.
The enclosure has a liner of glassfiber on the inside, and the bottom of the deck has two coats of epoxy. the cells are potted to the enclosure with natural curing silicone same goes for the rest of the electronics. however everything but the battery is made to be modular so if one component blows up you can swap that without having to solder anything.
If the battery dies you would have to get a new enclosure with it. not ideal in terms of service but in my opinion it is worth the tradeoff for the added durability and preventing issues in the first place.

[LexHoja]

Not very reassuring
I have emailed the creator but no luck here, all is quiet. He’s probably busy on something else in his life; he picked up studying again after this “BoardofSweden” thing. This BOS venture has died a silent death i think. He HAS helped me out with a motor dying last year, refunded me a new motor and was quick aswell.

I wonder what “potted” to the enclosure means… It seems to me that with a lot of sweat i would be able to dismount this battery, and maybe save some of it ? I don’t really care about the loss, willing to spend on a total new battery. So i do need to clean the enclosure up, which should be doable ?

Next step ; I’m thinking of approaching Simeon on here ; seems a very reputable battery-maker from my country. Meaning i have to clean out this enclosure so he can build something nice, maybe even a little bigger

[LexHoja]

@Simeon , i have called for your help … pm’d

[BenjaminF]

@LexHoja

So i do need to clean the enclosure up, which should be doable ?

If you dont have experience with liion batteries and how to safely handle them, then I dont suggest trying to do that yourself. The risk of a fire is very real.

I think you’d be better off sending the whole enclosure (or perhaps the whole board) to a reputable battery builder, and let them remove the pack from your enclosure. Simeon is a good choice if he’s willing to take the job.

@LexHoja

I wonder what “potted” to the enclosure means

Likely it means that the battery is stuck to the enclosure with lots of silicone. Based on those pictures, it seems like the cells are stuck to the enclosure directly, which not only makes removing them much harder, it also makes removing them more dangerous.

If you decide to remove the pack yourself, here’s some general advice:

• Unplug all connectors from the battery/bms/esc before doing anything else.
• Clip all of the wires and remove the loose wiring from the enclosure.
• Clip each wire separately, one at a time.
• Clip each wire as close to the cells as reasonably possible.
• Insolate each wire as you clip it. A simple piece of electrical tape works fine for this.
• Insolate any exposed metal of the battery (nickel, solder, copper, etc.)
• Do not attempt to remove the nickel p-group connections. Leave the p-groups intact and treat each group as its own unit.
• When removing the p-groups from the enclosure, do not pry or cut with any metal tools. The cells/p-groups should always be treated as “live” and capable of producing a short-circuit.

[LexHoja]

Thanks a lot, very usefull + helpfull info . I am actually thinking of the safest + best situation ; sending over the lot

[Simeon]

Unfortunately I don’t have much time for these big troubleshooting shenanigans at the moment :')
But I’ll chime in on here.

@LexHoja

Weird that the BMS didn’t cut off the overcharge… Maybe also faulty? Are the temp sensors connected? (the -30°C indicate they aren’t)

@glyphiks

I’m placing bets on a cell shorting on the carbon

most likely that or a loose weld. Either way, the pack (or at least p-group 5) has to come out and with that amount of silicone it’s gonna be a pita…

Overall I don’t like how this is built… basically no insulation around the cells and solder joints besides a thin layer of fibreglass on top of the carbon? How did John think this is sufficient?

[LexHoja]

I assume by hearing this that you are not building batteries then atm ?

From what i read in the reactions; this battery doesnt need troubleshooting+repair… It needs total changing to a new+improved German quality battery. I don’t feel safe with this battery anymore😅
I’ll get the enclosure cleaned out, and then you can do your magic. I’m not sure if you don’t like the idea of repairing something that was’nt good to start with, or that you’re indeed short on time?

[LexHoja]

Relieved that this battery is out of my garage/house. Lee, an Englishman from Holland who used to be on here (the community) too I heard, has taken on the job🤙🏼

Lee has built my big battery for my Flux-board years ago, and that one is still going strong👌🏻

[LexHoja]

So here’s what he’s up against , taking the BoardsOfSweden battery apart

[LexHoja]

[LexHoja]

He was especially worried/surprised by the sharp edges of the nikkel plating not being rounded and possibly puncturing through that epoxy and touching the carbon Not to mention all the other goo and shit he encountered

In defence of John from BoardsOfSweden ; he DID mention that the battery would mean a total replacement/exchange of that+enclosure when having trouble with it.
Because of how it was constructed (goo/glue/sillicone/total hell) he would send customers a complete new enclosure with battery mounted in there as an exchange when needing warranty☝🏻
Knowing this ; i tried to contact him a month ago about my troubles and he has yet to respond…

[LexHoja]

[LexHoja]

New Boards of Sweden pack. Seems like a nice job.
Englishman in Holland Lee did my Flux battery which has been going strong for 4 years now, this battery looks same or better.

Much better than it used to be ! Safe+sound !