Desperately need help!!!
@Shadowfax i got your sentinel today and board is now charging. Thank you!
Following here as I want to figure out this work around too for once I’m soldering…
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Curious why these things are burning out.
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Same.
While searching around and diagnosing mine was the issue I’ve seen a few with the same issue…
Curious though (and maybe am exposing my noob status here) - like in my case where I don’t need lights or accessories - would it be possible for someone with the know how to solder up a pigtail type device that plugs in and connects everything the same way?
I’d pay for at least a couple of those…
I bypassed the sentinel for charging on 18s lacroix after it was the likely culprit in killing the first battery pack - leading to the original owner to rage quit esk8.
@Skyart shared that he has seen the sentinel do bad things to batteries, particularly on the 18s models.
It’s a nice little piece of gear for automatically turning on and running a 12v buck converter, but I’d definitely remove it from the charge circuit.
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Fantastic to hear that the sentinel sorted things out for you. Cheers!
How do I bypass it for charging? Wouldn’t that bypass the bms?
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You don’t bypass the bms for charging. Only bypass bms for discharging. Discharging is totally separate from charge on the sentinel, so don’t worry about that.
First off, wear eye protection when you do this, and do this in a fire safe area. If you short something, you’ll send >1000 amps through what ever you shorted. I’ve turned an allen key into a quick blow fuse before. Lithium ion batteries are no joke. Be safe and confident in what you’re doing. If you aren’t, best to pay someone else to do it.
Disclaimer out of the way, it’s simple to take the sentinel out of the charging circuit. Just unplug the charge port on the sentinel (the little mr30 IIRC), and wire up your charge circuit as shown below (drawn by @Common_good)
- make sure you have B- on the BMS going to the battery negative.
- make sure you have C- on the BMS going to charge port negative.
- charge port positive goes directly to battery positive.
@Kiwijase tagging you for future reference on this too.
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Lol. I replaced 11 brand new batteries here, i think 8 of which arrived totally DOA after a trip on the slow boat from Canada. I have zero faith in the sentinel, but all of them were still functional, despite killing the batteries.
If it were my board, I would 100% delete it.
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I have a barrel and in the last month or so when i plug my charger to the port it doesnt charge right away.it may take up to a minute or so then start charging but only for seconds at a time. The board does this all day then only gets up to maybe 70 percent in about 24 hrs of charging. I cracked the battery box open when i was changing motors and noticed “the sentinel” I didnt know what it actually did, but i do recall seeing something off about it. so if that is my issue how can i delete it and get a quick full charge? Thanks in advance.
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Holy shit, thats a big USB cable
It sounds like your battery has serious issues and probably needs to be replaced, but we can help you diagnose what is going on.
Download Xiaxiang BMS app, connect to your board, and take a screenshot for us to see what voltage all the p groups are currently at.
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here is my battery info, i think the sentinel is the culprit. when i was changing out the motors i noticed it looked funny, like a small bit of soot was on it. but at the time i was in a hurry and wanted to get out and ride and just thought that is a tomorrow problem.
That battery is toast if those voltages are accurate.
Cell voltages should not fall below 2.5v or above 4.2v. Anything outside that causes permanent damage to the cells, and can start a fire. It also looks like group 9 shorted out, and somehow the BMS allowed group 8 to be overcharged.
Try to measure the groups directly with a multimeter to verify that it isn’t some faulty BMS wiring or something like that.
That’s your smart BMS leads breaking, not the sentinel. The battery construction of those boards are notorious for readouts like this. It’s repairable with some basic soldering equipment.
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Yikes, that is terrifying.
That battery looks like a bomb. 5.53v is insane. I hope that’s not correct.
Like Jake said, the next step is to grab a $20 multimeter (voltage reader) off amazon if you don’t own one already. Pull the enclosure off, and measure the individual battery group voltages.
If @Evwan is right, it’s cheap fix, but there’s also a chance you have loose welds in the battery, and the voltage of the groups is way off what it should be.
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I’m with @Evwan . It looks like one or more balance leads have been compromised. Definitely wanna check everything with a multimeter.
Thanks for the advice, I just got my new board assembled yesterday, I put the barrel up on blocks, took the chain drive off along with the matrix 3’s and tires. Now with the battery pack from the barrel, is there a company/ person who could take my pack and drop the dead cells and get the pack back on track? Thanks!