My new (USED) lacroix arrived dead - please help

I’m so bummed. Bought a lacroix jaws off FB marketplace last week. Shipped UPS ground and arrived today.

It would not turn on, so I opened up the case and tested the battery leads. The 12s4p pack is sitting at 6.39v.

I’m at a loss as to what to do. The seller seemed like a genuine and honest guy and I think it must have been something during shipping that drained the battery to zero. I have no idea what to do. Please tell me I’m missing something obvious or that there is something else I should check. It’s a july 2020 jaws.



I am sorry for your loss.

That BMS does look like the LLT smart BMS. Which means that if the board was left empty after a ride and then never ridden for like half an year or an year, it could have depleted the battery pack by constantly having Bluetooth turned on.

If that’s indeed the case, the seller could be legit. I can’t rule out that the seller screwed you over knowingly though.

Your best bet is either trying to get the seller agree to a return, or to a partial refund which covers the cost of replacing the battery. If the seller won’t help you out, I can only hope you payed with Paypal Goods and Services.


The first thing I would do is check all the connectors on the BMS to ensure none of them came loose. I would just unplug then replug all the connectors as the easiest way to make sure they’re fully connected. That would be my first guess at least if you didn’t do that already.

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The BMS is a 15A BMS according to its sticker on top, so it’s charge only / bypassed for discharge. Which means that you should always be able to measure the battery’s true voltage in the main discharge connector.


I appreciate the idea, but it is a BMS bypass as @Dinnye mentioned. I’m measuring the battery’s true voltage directly from the leads at 6.39v - so it is completely toast. :frowning:

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Connect to the BMS.over Bluetooth. If you’re on Android I can send you the apk file.

Passcode should be 123456

Thanks Dinnye - I talked with the seller on the phone and he has another Lacroix. He is the original owner of the board and I’m confident he wasn’t out to scam anyone, so I’m hoping we can arrive at a fair resolution. I did pay with goods and services. After someone tried to scam me once, I made it a life rule that I would never use friends and family online, no matter how much I trust someone.

It is indeed the smart bms with bluetooth. The seller said they charged it before shipping, but I do not have confirmation yet that the board was tested. In retrospect, this was a very stupid thing to overlook. I had a long conversation with the seller about the details of the board, but I failed to ask him to facetime and demonstrate that the board works. I just took it for granted that the board did in fact work. I suppose that something strange could have also happened during shipping.


I think the voltage is too low for the BMS/bluetooth to work at all.

I have the Xiaoxiang BMS app and only the LLT in my DIY board shows up when I search for devices.

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Possibly loose or broken +/- lead under the heatshrink? Anyway you can check voltage elsewhere on the pack?

Good idea. The P groups are PCB packs, so not the easiest to test, but some have solder joints accessible. I just tested some of the P groups and it looks like they are all very low.

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happened to me on a nazare pack, cut out while riding.

that really sucks man. I bought a board that was all fked up and the seller didnt really point out everything that was wrong with it. on the bright side it looks like you can fit a bigger battery in that enclosure so atleast if you put more $ into it you can see it as an upgrade : )

Yeah, lacroix originally used 20700 cells before those became prohibitively expensive / impossible to source. When they switched to 21700 cells, the enclosure didn’t fit 6p anymore. I’m assuming that’s why they redesigned their enclosures last year.

If I do end up resolving things with the seller and buying a new pack from a battery builder, I’ll definitely take the chance to upgrade and go with 20700 cells - slamming a 12s6p in there. I suppose 18s4p would also be an option, but then I’d have to replace the stormcore, BMS, motors, charger… way too much work.

I’m really fucking bummed - this board has the perfect amount of flex and I even balanced the wheels before I realized it wouldn’t turn on.

I texted the seller but no response yet. He’s in Colorado, so I assume he’s out enjoying his Saturday evening.

dude I had to replace so much on the board i Bought. not all of it was nessicary to replace i just felt like it was build so slopy. it bothered me so i just replaced the parts. you live and learn. id say stay off of FB market place when buying boards. I think if you played your cards right you could move the ESC into an Enclosure on top and have more room for a battery.

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Unplug your balance lead and measure voltage in each p group. If it all adds up to what your getting at the xt90 that pack is probably toast. Might have been powered on during shipping which could have drawn it down. That voltage looks like the default voltage start up for vesc programming

If his down to refund you do that or if you want to really keep it get a quote for a battery and ask him to cover it or a percentage.


Or if you’re covered under buyer protection send it back and eat the cost of shipping. At least you’ll have enough $ to get something else that pops up.
Of course I’m not saying the seller did anything shaddy but you shouldn’t have to be held responsible.

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Looks like a 12s4p P42a pack from @Skyart is $650 + tax, shipping, potential extra for segmented enclosure pack.

I’m going to ask the seller to either provide a shipping label to return everything, or refund the amount to replace the battery.

For someone who knows - if you left a stormcore on for 5 days, would it drain your pack to completely dead? Or is it more likely that the battery was at 6v when the seller shipped it, and probably just didn’t realize it?

No. That takes a long time

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Stormcore has auto shutoff too…I would be hitting up the seller regarding whatever sort of shenanigans may be happening

If you buy a pack use discount code “Diy5” no extra for the segmented lacroix enclosure…but I think your enclosure will fit 12s6p DM me


Unless someone disabled it for some reason. Not sure it’s defaulted on

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