10s3P vanguard keeps blowing up switches (pictures)

So I have had my Boosted clone for a while now and I can’t keep it running. It’s always something.

I have blown through 2 electric switches and I wonder if it is my wiring. So I am appealing to the hive of experts to point out my failures so as to hope to redeem myself.

The Problem with the switch on I only get 4.3 volts output

Meanwhile the Battery is outputting 39.4v (40v) from upstream of the BMS

And on the output of the BMS into the switch it is reading 33v.

That’s like a drop of 6v across the BMS. And a loss of 28v across the switch in the on position. Do I have this wired up wrong? Am I an idiot that shorts out his stuff? Here is my wiring diagram setup. Sorry I only have a dry erase board here.

Any Ideas? At this point. I can use whatever. I am really close to just selling what I have off and starting from scratch haha.

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Here is a better visualization of how my voltage is dropping across the battery and switch.

Usually when those E-switches fail it locks in the on position. Have you tried just by-passing the switch? Can you include a diagram for the balance wiring?

That eswitch is crap it’s not your setup. Use the vedder switch or a loop key if you’re on a budget.

Where did you get those enclosures ?

I spoke with Dextor and he mentioned getting one of them as well. He said you might have some for sale!? Ehhh!??

And I made them out of fiberglass. I have a build thread here.

It’s super nice good job with that enclosure.

I don’t really sell switches I just had a small stock of them for my batteries that I sell. Hit up @goldenHusky he has some quality switches for a good price

The balance wiring is just standard from the BMS website

Man, which switch is it? Link Please

Thank you! It’s taken me 6 versions to get to this point. I have sent @goldenHusky a message! Thanks for the recommendation.

I’ve had 2 of those switches fail on me. One worked for a while then overheated and got fried. The second just failed for no apparent reason after about 5 min of operation. Now I use a BMS with built in switch and that has been very dependable. I’m not familiar with battery supports bms and assuming you have all the balance leads securely connected and wired correctly, I cant see why there is a voltage drop at the output of the bms. Maybe @barajabali has an idea about this.

That’s the exact situation I have had, one worked for a while and this one blew right away. I have looked into a BMS with a switch built in and would love that. Do you have a link from where you purchased your BMS from? I am not the biggest fan of this one. It is what failed last time. I have gone through with my multimeter on each balance lead and measured it and it is all good.

So it may be several problems. The BMS and the Switch. Honestly maybe the bad BMS might have spiked and fried the switch.

This is the one I use, you can order directly from the company in China but they have a minimum order policy of 2 modules. Or, I have 1 extra, brand new unopened that I could sell for cost + shipping http://bestechpower.com/37v10spcmbmspcbforli-ionli-polymerbatterypack/PCM-D223V1.html

SOLD! Ill PM you!

@denton Xt-90 loop key Is the Best simple option so far.

I had the same issue a year ago, I understand that the electric switch is cool but I learned that a physical disconnect is a safer and more reliable option.

And keep up the good work :slight_smile: That is a great work on that enclosure.

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I agree it is, however I wanted as professional looking and operating board as possible. So that means any idiot can operate it with one button. So far… not so good haha

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I feel you man.