The Jehu PCB v1.1 Testing and Review thread

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Crimp Daddy

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The purpose of this thread is to document my testing ofthis open source PCB designed by Jehu Garcia.

While this isn't my first time ordering PCBs, it is my first time using JLCPCB and I must say the experience was pretty good.My package arrived today via DHL and everything was boxed and packed well.

From what I understand this is the 2nd version of this board. The PCB is stamped with a v1.1 marking.

Not really sure what I am going to do with these... butI will likely test a few board to failure to see it's catastrophic breaking points, and perhaps build a small project / powerwall to try and identify it's pros and cons.

Stay tuned for more photos and comments. In the mean time, where are some photos of what arrived.

I am still acquiring parts and pieces to make this happen...


image_gpamsp.jpg

image_odmqzi.jpg

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image_ajeexd.jpg
 

Korishan

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There's actually 5 revisions. The latest one is a lot better and can handle more current.

Here's Justin Kenny's test video:

That way you can see what he's done and then expound upon the data.
 

Crimp Daddy

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Excellent, thanks for that link, I didn't know Justin has his own channel! Trying to stay on top of it but I missed that video but I have now subscribed.. Looks like they are testing file "7s_holder_v12."

The testing there looks to thorough, and it reminds me that I still need a thermal camera, an expensive toy I have wanted for a while.

I was under the impression I got the latest board printed... the file name that was distributed by Jehu was "7s_holder_v13_smd"

Do you have a link to what you know is the latest file so I can compare the Gerbers?
 

Korishan

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The testing videos aren't public ;) I asked him first before posting the link. He's happy to have others test the boards.

Not all the gerbers for each revision is available yet as Justin is still testing. I'll ask him though.
 

Crimp Daddy

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No worries... this isn't even my primary project, but I did find the PCB builds interesting so I got the "v2" files from the below YouTube live stream.


As far as I know, there are only two versions in the wild right now that were distributed by Mr Garcia.

7s_holder_v12 aka v1 (Ver 1.0 printed on PCB)
7s_holder_v13 aka v2( Ver 1.1 printed on PCB)
 

rev0

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Apologies to all for the bad naming; there are only 2 publicly released versions of the board.

"v1" as Jehu called it, which has file name "7s_holder_v12.zip", which had through-hole holders only on a single side, and only 1 positive contact on the same side as the negative contact, and higher breaking current balance lead fuses as tested in that video
"v2" has the file name "7s_holder_v13_smd.zip" is the final publicly released version which has both through-hole and SMD holder support on 2 sides (for SMD) and 2 positive contacts with their own pack level fuses, and reduced breaking current for the balance lead fuses (not yet tested, but around 7A expected)

Any earlier versions (e.g. v10, v11) were just investigations for how to put it together when I was emailing back and forth with Jehu. They were never finished nor released.
 

Crimp Daddy

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Based on that, looks like I have 20 boards of the latest and greatest, thanks for confirming... building and testing will commence as time permits.
 

Peter T

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Mine seem ok. I've got V1.0. Ordered 10, But only using 2 at the mo. Only sorted the BMS Today. But been running for two day's now. At some point the trace's on C2 have burnt out. But it was running without the BMS.
 

ecam315

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Any thoughts on somehow modding the boards so they could plug into a backplane like someone is designed in another thread? Or at least just the BMS pins?


Thread : The finish-ish of a pcb based 14S 80P powerwall
 

Crimp Daddy

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Quick Update / Progress Post

Pretty busy around here but got some time to knock out one PCB just to do some light testing...

Initial observation, comments, notes:
  • I like the design, it went together easily.
  • I used a 5A glass axial fuse because thats what I had around, still digging though the parts bin for some other stuff I think might work well.
  • XT60 to Anderson adapterwas used because thats my standard for most of my gear.
  • Balance cable used instead of stacking header for now.
  • I havent really loaded it up, but I can tell its not ideal for anything high drain.
  • Light sag at 40w load, going to use power cells to see if anything changes but I am leaning towards high IR coming from cell holders.
  • I want to try the SMD cell holders which I still need to order so I can do some real performance testing.
  • Still waiting on parts like the standoffs, stacking headers.


image_fzirzp.jpg

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rev0

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Nice work. By the way, are you in the US? I'd be interested in buying a few boards to do some testing also if you are. Had an offer from someone in the UK to ship some over but that seemed a bit ridiculous compared to just buying new ones from China.

At least for DC/AC resistance measurement, the SMD holders seem much more consistent, and have about half the resistance. Though the resistance I measured on either was still pretty small, around 30 mOhms I believe. I will be interested to see how the SMD ones fare under the same loading, seems most people aren't interested in using them for some reason, I thought they would be more popular since it supports 2-sided loading and (presumably) higher power.
 

Crimp Daddy

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Thanks, I am in the US, send me a PM and we can talk about getting you some boards.

Which SMD holders were intended for this PCB?

These are the ones I am using in the photos below... they are pretty nice, but they do cost a fair bit more than the other, which is probably why people are showing less interest.

Personally I think they are great, and I do throw some decent amperage though them without any real issues. I use them for my internal resistance testing and for charge/discharge of high drain cells.


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Korishan

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ecam315 said:
Any thoughts on somehow modding the boards so they could plug into a backplane like someone is designed in another thread? Or at least just the BMS pins?


Thread : The finish-ish of a pcb based 14S 80P powerwall

Yeah, redesign the PCB layout to incorporate that particular design. Not that difficult if Justin/rev0 is willing to give the data files (not sure if you can edit gerbers or not; haven't tried yet)
 

rev0

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I haven't worked with backplanes before, would that just be changing holes to SMD pads which would slide into a holder like a PCI slot? Should be easy enough to do if I get the datasheet/dimensions of the desired holders.
 

Crimp Daddy

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rev0 said:
I haven't worked with backplanes before, would that just be changing holes to SMD pads which would slide into a holder like a PCI slot? Should be easy enough to do if I get the datasheet/dimensions of the desired holders.

Precisely like that...

Backplanes are very common place in PC server applications, many examples can be taken from that. Hard drives, power supplies, and other various items can be observedas good examples.

Here is a power supply from an HP Proliant server which had dual hot swap power supply units. The + / - and other control circuits are all made in one simple insertion of the PCB. In our case, we can have power and balance leads all available to the backplane which makes it easier to scale.


image_mscjhn.jpg

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Lots of cool things can be done at the backplane level... for example if all the battery boards were just parallel holders, the backplane could be designed to either be a 1sparallel moduleor a series module at pack voltage. Changing only the backplane could suite two very different designs and applications making it even more versatile.
 

rev0

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CrimpDaddy said:
rev0 said:
I haven't worked with backplanes before, would that just be changing holes to SMD pads which would slide into a holder like a PCI slot? Should be easy enough to do if I get the datasheet/dimensions of the desired holders.

Precisely like that...

Backplanes are very common place in PC server applications, many examples can be taken from that. Hard drives, power supplies, and other various items can be observedas good examples.

Here is a power supply from an HP Proliant server which had dual hot swap power supply units. The + / - and other control circuits are all made in one simple insertion of the PCB. In our case, we can have power and balance leads all available to the backplane which makes it easier to scale.


Lots of cool things can be done at the backplane level... for example if all the battery boards were just parallel holders, the backplane could be designed to either be a 1sparallel moduleor a series module at pack voltage. Changing only the backplane could suite two very different designs and applications making it even more versatile.

Cool, yeah as I said, finding the mating connector for a 1.6mm thick (or 1.2mm I think is another standard thickness from JLCPCB) would be the deciding factor on how to proceed laying it out. Any idea on cost also?

There is another user that alreadydid a 1sXp backplane.
 

Crimp Daddy

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Sooo Ive had a busy night. Pretty much missed the Jehu livestream playing with batteries ironic

Update / Progress Post #2
  • Will use this PCB as-isto test various 7s BMS options including the Chagery BMS8 and the Bluetooth BMS
  • Going to experiment with a non-stackeddesign to utilize horizontal space instead
  • Resettable Fuses instead of one time use for field durability. No need to disassemble and re-solder in the event of an over currentcondition.
  • Load test usingan efficient DC off-road grade fridge/freezer.

Instead of stress testing these things to the point of failure I decided to just try to make something decent instead. Its pretty obvious these are best suited for low current applications, but with a good wiring setup, it could easily scale. I have some ideas I will share in another post.

I don't do a lot of video, and I am not that active on YouTube but here is one of the load test using a single board and a real world load... my truck fridge.


Here are some photos from my other talking points above.

The BMS that I am FINALLY getting around to testing. My main focus has been my 15s system so I haven't picked this up in a while. I will be getting one of those Bluetooth BMS balance boards to test as well.


image_cojfeg.jpg


Thinking about how I might want to build the battery base for the fridge... Lay flat with afuse block to put everything in parallel. Each branch is individually fused at a service point with resettable fuse on the PCB.


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In the spirit of talking about backplanes Maybe aDIY cabled backplane for balance leads. Still brainstorming but I already had these parts in the bin. Thinking about something like this.


image_suftgq.jpg


That's it for now... ill keep it going as I make progress. I'm actually less worried about the electronics than I am about the base. Not sure what to use, but ill most likely explore using wood. Anyone have any ideas?
 

Korishan

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Peter T

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Nice work crimp daddy. Does your bms get hot. Mine gets do hot the screen goes black. And the 8 wires also get warm.
 
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