Ok, I go and drink my coffee first…
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Maybe just a spot on the PCB with industry standard pads/holes for a 1/16 brick (or similar standard size) DC/DC converter? That way the end user could plonk down whichever one has the voltage input and output they need, without you needing to manage multiple SKUs?
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Oohhh…I like that!
Probably not an empty spot as that would take up a lot of room but mounting holes could be provided over a low profile section of the BMS for the converter’s board if there is a standard hole pattern. Then a header or wire jumpers can be soldered from the BMS to the converter. Thanks!
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The brick system (not sure if you’re familiar with it) generally mounts by the pins. At least the smaller ones do. Not sure about the full or 1/2 brick sizes, since they’re pretty chonky.
They’re definitely not the cheapest converters you can get by a long shot, but they’re standardized in size/shape and mounting style, and available in a wide range of input and output options.
(edit - oops, missed an important word XD)
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Ahh…I forgot about the pin mounting! Excellent suggestion, thanks again!
Found it…
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For those unfamiliar, DOSA-standard power bricks are awesome.
And they can be very power-dense.
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Supporting a 1/32 brick might be more appropriate. 
More limited choice though?
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True. The 1/16 and 1/32 are probably more than ample for most of our applications.
The really high power bricks still need quite a bit of forced air cooling, and are pretty expensive.
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None of either size on Amazon though. That will be where a lot of people will want to buy their converters versus DigiKey/Allied/Newark and the minimum orders and shipping they need to deal with. 
Might not work out supporting these. I really like the advantages of a standard hole pattern though. I guess I can always include standard pads for soldering wire leads to any converter board.
Lots to think about.
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This is true. Free shipping on everything has spoiled me 
They definitely fall into the “industrial” category, so I’m not surprised nobody is selling them on 'zon.
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I think this is a wrong assumption.
I think people have trusted dumb bms’s for quite a long time on esk8s.
what they don’t trust is that one off pack builds being banged around on the streets used and abused, are holding together well. or that the cells they sourced are 100% good. or that the high discharge rates they’ve been using have been tolerated by the pack and it’s still holding up evenly across pgroups, etc. a smart BMS gives more peace of mind by giving better visibility into how the pack and each pgroup is doing.
In addition it becomes the faster debugging tool for the rather frequent case of… "something weird happened, is my battery pack f’d ? " I could open it up and sample it once with a voltmeter. sure but smart bms is better.
I don’t see why you’d want a reliable dumb BMS, when one could have a reliable smart BMS.
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Hey @Battery_Mooch , you must have jinxed me as one of my P groups died over the weekend
Good thing I can write about it and what I did to troubleshoot and locate the P group using a not so smart BMS 
Put my board to charge, the YZ Charger light was indicating green – charge complete. Check the battery level indicator/volts and it’s a 44.9
- I tested the charger to confirm it was charging past 44.9 volts on my other builds first, the charger works
- So the pack won’t fully charge…… I have a dumb BMS I have no choice but to open the enclosure and test each P group.
- P group 9 was reading nothing, it’s dead and needs to be replaced.
If I had a smart BMS I would have saved about 2 minutes of time in my troubleshooting endeavors. The smart BMS would have told me that the P group was dead and which one …… Big deal I figured that out for myself because I’m learning how to build battery packs now…. So maybe for us esk8 DIYers a dumb BMS is a good fit, we have the skills (Or learning them) to fix shit when it breaks.
For the majority of people who don’t have the capacity to test and troubleshoot then a smart BMS would be of use, they can use the data to let their preferred battery builder know they need help and would be able to accurately tell them what’s wrong.
For me, I just want something that’s bulletproof and that I never have to worry about. I just want to ride.
Put me down for 2 units
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Good experience to share.
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It finally worked!
I spent frakkin’ years working on my Sales Generating Field Emitter technology and it has finally managed to zap someone’s pack and create a possible customer.
Whew…I was getting worried all that time and expense was for nothing. I figure that if I can zap another few thousand packs, and they all become Mooch BMS customers, I could actually break even on this project. 
On a more serious note…
Thanks for your post and your interest in my BMS!
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What cells were you using? I’d lose my mind if I had a p-group of brand new p42a just go dead like that.
They are Samsung 29E cells. They were part of an Alian Power pre-made 10S3P pack that I pulled apart and converted to a 12S3P pack. This is the first pack I’ve ever worked on and I used to practice my spot welds and battery building skills with so I expected as much.
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Any progress with this @Battery_Mooch ?
I came up with another feature request as I was building a battery the other day:
- Allow the balance wires to be in any order
Currently BMSes have the balance wires numbered from 0 to 12 (for a 12s pack) (why wire the 0 wire if it’s the same as common negative I don’t know. Kinda dumb imo), and you have to wire them respectively to cells 1 through 12. But sometimes battery pack layouts don’t allow for a clean 1-12 layout, so you have balance wires crossing over one another, which then requires extra insulation if you’re a perfectionist battery builder like everyone should strive to be.
Well, that got me thinking – what if the order didn’t matter? Then you could wire the balance wires in whatever way is easiest / prettiest / safest, and you also avoid a failure scenario from accidentally switching 2 wires up 
Bonus feature: allow either the balance plug or the main terminals be connected to the BMS in whatever order. (As in time 
– which one you plug into the unit first) Because that’s another mistake that’s way too easy to make 
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This is a great idea. I personally wouldn’t use one because I’m still not perfect at assembling packs and I like to monitor for any issues that might creep up.
I feel like this would be really good for an OEM or pro builder that is confident in their welds and assembly of the pack, and shipping the pack to someone who doesn’t want to or need to care about pack health.
I feel like for this to be successful, it needs to be really really reliable. So reliable the cells or connections become the weakest parts of the system. As you put it “bulletproof”
It also has to be affordable. Many people have scoffed at the price of the Trampa BMS (£200) so if it’s even close to that, many will just go with a cheap Daly other china BMS. Just pointing out that if people are going to want to use this, it has to provide more value than something comparable or else only a few niche DIYers will even consider it, let alone actually use it.
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What’s the correct order?
numerical order? I think he’s saying
“why can’t we just stick the balance lead from group 5 into the connector for group 3 and just have the BMS figure that out for me?”