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

grumble

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Aug 9, 2018
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71
Afternoon all,
Just a pic of the start of my powerwall.
Pcbs are my own design.


image_iiioyv.jpg
 
Modular, flexible, and professional finish.
 
Interesting. Do you have anything to connect or support the battery boards on the opposite end of the main board?
 
Cherry67 said:
Modular, flexible, and professional finish.

Thanks.


Mazlem said:
Interesting. Do you have anything to connect or support the battery boards on the opposite end of the main board?

I'm toying with the idea of using some kind of slotted apparatus, but those edge connectors grip well and the pcbs are the same height, so the shelf might just be good enough.
Also, if you need to grab something out quickly, the less in the way, the better.
 
wim said:
Nice work .... looks good.

Is there some kind of cell level fusing ?

Thanks and yes, difficult to see, but there's a fuse wire between the two pads above each cell.
 
Looks really nice and interesting cause I don't like the soldering on cells. Most likely due to my handling, I'm quite handy but soldering 18650's doesn't really go well for now.
Have you already been able to test out a full pack ? How is the heat dissipation at the terminals from the cell holders ? I remember Jehugarcia was experimenting with something similar and when he tested the pack under load, the terminals got way too hot.

So hopefully you're design got that sorted out and you're willing to share the PCB layouts ?
I certainly would be interested.
 
yoeri_w said:
Looks really nice and interesting cause I don't like the soldering on cells. Most likely due to my handling, I'm quite handy but soldering 18650's doesn't really go well for now.
Have you already been able to test out a full pack ? How is the heat dissipation at the terminals from the cell holders ? I remember Jehugarcia was experimenting with something similar and when he tested the pack under load, the terminals got way too hot.

So hopefully you're design got that sorted out and you're willing to share the PCB layouts ?
I certainly would be interested.

No testing yet, but I'll let you know how it goes.
I saw Jehu's vid, but can't remember how many amps he was pulling.
I run a 48V system, so will spread the load to a minimum.

I'm sure to share if they work well.
 
This pcb style really interests me. Looks good. Fuses easier to work with. Completely modular and easy access to each cell.
I take it that whats shown in the photo is all parallel? and you will have 14 of these in series for a 14S80P wall?
Also, how do you calculate the track widths for the pcb? I use the nickel strip charts for my own nickel strip build. Is there an equivalent for pcb tracks?
 
Daveyboy said:
This pcb style really interests me. Looks good. Fuses easier to work with. Completely modular and easy access to each cell.
I take it that whats shown in the photo is all parallel? and you will have 14 of these in series for a 14S80P wall?
Also, how do you calculate the track widths for the pcb? I use the nickel strip charts for my own nickel strip build. Is there an equivalent for pcb tracks?

All parallel and will have 14 in series.
Fuse wire is a pain, because it's so thin to work with. I've got some axial glass fuses on order, which will speed thing up.
If I had to do it again, I would put pads for fuse holders, so that you can put ordinary 20mm glass fuses in, or use the pads for axial fuses, or just plain fuse wire.
There are sites for calculating current capacity of pcb traces.
The backplane pcb is just 2 double sided traces, in 2oz copper, for what I'm hoping will be ample for my 48V system.
Cell pcbs are just 2 double sided traces in 1oz copper.


Headrc said:
Nice ....how did you design and produce those boards?

Thanks.
I use an old school pcb software app called Traxmaker, then send the gerber files to China and wait a month.
 
grumble said:
The backplane pcb is just 2 double sided traces, in 2oz copper, for what I'm hoping will be ample for my 48V system.
Cell pcbs are just 2 double sided traces in 1oz copper.
2 x double sided, so 4 traces total? Sorry for my dumb questioning, i'm just interested in learning about what you are doing. It's something I might have a go at when i'm finally done with my more traditional style powerwall and I need to move to another section of wall. It sure looks easier than what i'm currently doing. I'm designing my system to handle 1 amp per cell, and 80 amps through a pcb just seems a lot to me with my very little knowledge of pcb's :rolleyes:


Also, what are your thoughts on trace fuses? Too much of a fire risk maybe?

Like in the photo of the attached: https://electronics.stackexchange.c...in-sections-of-copper-traces-be-used-as-fuses
 
Daveyboy said:
grumble said:
The backplane pcb is just 2 double sided traces, in 2oz copper, for what I'm hoping will be ample for my 48V system.
Cell pcbs are just 2 double sided traces in 1oz copper.
2 x double sided, so 4 traces total? Sorry for my dumb questioning, i'm just interested in learning about what you are doing. It's something I might have a go at when i'm finally done with my more traditional style powerwall and I need to move to another section of wall. It sure looks easier than what i'm currently doing. I'm designing my system to handle 1 amp per cell, and 80 amps through a pcb just seems a lot to me with my very little knowledge of pcb's :rolleyes:


Also, what are your thoughts on trace fuses? Too much of a fire risk maybe?

Like in the photo of the attached: https://electronics.stackexchange.c...in-sections-of-copper-traces-be-used-as-fuses



Pos and neg on 1 side... pos and neg on t'other... with vias, holes and pads joining them together... If that makes any sense.
I've got a total of 90mm traces for each pole, which according to this calc is plenty.

image_hxabin.jpg

Trace fuse is entirely feasible, but if it blows, you'll end up putting a wire across it anyway.
 
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