There's a new wall in Germany!

[IronSky]

Nice coffee cup

Do you want to test the glass fuses the RageaveJoe used? I have 1000 pieces I could give you a few to test. 0.5 Amp








Iron

 

[owitte]

Just curious, what's with the resistors on the first pack-pic?

that are my fuse wires . The resistor legs perfectly fit in thickness and length - and the're dirt cheap in China, 1800 pcs for ~ 7, good for wiring 1800 cells on both ends. I first solder one end of the resistor to the battery, then cut it off close to the resistor in the middle and use the second half for the other end of the battery. The legs are exactly as long as I need them to bridge over the bus bar from one battery row to the other. Only problem: I end up with a lot ofamputated resistors :

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Nice coffee cup

Do you want to test the glass fuses the RageaveJoe used? I have 1000 pieces I could give you a few to test. 0.5 Amp


Iron

yeah, also have a t-shirt, see here .

The glass fuses with 0.5A are a little too small for me, but thanks a lot for the offer

 

[owitte]

vertical row no. 11 added last night, config is now 220p7s, 11kWh. Still another 5 rows to go until the wall is complete...







btw, after updating the cell counter, I lost my star :s

 

[alildabldo]

I like your design. Just curious, did you look at copper ground rods with connectors when you were shopping for copper pipes? I guess I'm curious if a copper ground rod could replace your horizontal bus bars. Keep up the good work.

 

[jesusangel]

I'm following owitte for busbars and his horizontal wall mounting and the cooper pipes can be easily flatten and hole to connect with the bus bars of every pack, you can't do that with the copper ground rods (you can but not so easilly).

 

[hbpowerwall]

vertical row no. 11 added last night, config is now 220p7s, 11kWh. Still another 5 rows to go until the wall is complete...







btw, after updating the cell counter, I lost my star :s

Yup - way it works I'll fix her up now

 

[owitte]

vertical row no. 11 added last night, config is now 220p7s, 11kWh. Still another 5 rows to go until the wall is complete...







btw, after updating the cell counter, I lost my star :s

Yup - way it works I'll fix her up now

Thanks, Pete Will this happen after every cell counter update? I'm planning to add another 140 cells/7packs/1kWh next week...

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I'm following owitte for busbars and his horizontal wall mounting and the cooper pipes can be easily flatten and hole to connect with the bus bars of every pack, you can't do that with the copper ground rods (you can but not so easilly).

I just noticed a disadvantage of my design: After using my powerwall for about 5 months without any problems (in fact, it runs continuously on battery despite a few days since then), I noticed, that the voltage difference between my seriesses was getting higher... from the beginning, it was constantly between 30 and 40mV. I installed a battery monitor with alarm function and set the alarm to 100mV delta. And then last week, the alarm woke me up in the middle of the night (very loud beeping sound). The voltage difference between the highest and the lowest series was more than 100mV since then, and I didn't know why this happened. I supected a malfunction of the balancers, but they measured ok. So I checked the voltage of each 20-cell-pack in the lowest series. Btw, this is one of the advantages of my design: If you have enough packs, it's no probelm to remove one for maintenance . But guess what, all packs were ok to my surprise :dodgy: . But I noticed, that the M8 nuts that fix the pack terminators to the bus bars where a little loose on some packs. So I checked and fixed them all. And -surprise, surprise- the voltage difference was gone! Well, actually not gone, but back to 30-40mV...

So, if you use the same nuts and bolts terminal connections I use, keep in mind to check them from time to time...

Have sun!
Oliver

 

[Korishan]

Might be worth using nylon lock nuts if anyone is building this type of setup. That way the nuts won't back off from the "flexing" of the metal during electron heavy weight lifting

 

[owitte]

think I'll use disc springs/spring washers, makes it easier for maintenance and the electron can use them as a trampoline

 

[owitte]

just a short update: Added another 140 cells, now 1680 cells overall, 240p7s, 12kWh. Didn't take pictures, because the visual difference between 11 and 12 rows is marginal (next pics when the wall is complete).

Also removed the first 2 100Ah SLA batteries (6 batteries whith 840Ah still in production) in order to find out if that makes any signifcant difference.

And I lost the star again with cell counter update, Pete, could you please... again...?

Have sun!
Oliver

 

[owitte]

I like your design. Just curious, did you look at copper ground rods with connectors when you were shopping for copper pipes? I guess I'm curious if a copper ground rod could replace your horizontal bus bars. Keep up the good work.

thanks . I didn't look at copper ground rods before, but I think they're much more expensive because they're solid. And I don't know about the lenght you can get. I buy the pipes in pieces of 2.5m for ~9 per piece. The plastic holders (original for 16mm plastic pipes) are dirt cheap and fit exactly, so it's very simple and easy installation.

---

I'm following owitte for busbars and his horizontal wall mounting and the cooper pipes can be easily flatten and hole to connect with the bus bars of every pack, you can't do that with the copper ground rods (you can but not so easilly).

Yeah, that's right. But don't forget to put some tin on the flat connection parts, remove the flux after that and use spring washers to fix the packs. I'm very curious about your installation, hopefully we can see some pics here soon .

 

[jesusangel]

[quote pid='11067' dateline='1502357824']
Yeah, that's right. But don't forget to put some tin on the flat connection parts, remove the flux after that and use spring washers to fix the packs. I'm very curious about your installation, hopefully we can see some pics here soon .
[/quote]

I hope next 2 weeks that I have holidays will have something working, my packs aretaller than yours and I have no space to set 14S horizontally, so I think I will do 13s, not a big difference for 48v (44.2-53.3 range).

http://secondlifestorage.com/t-JAP-Just-Another-Powerwall-or-Jesus-Angel-s-Powerwall.

Regards

 

[owitte]

I hope next 2 weeks that I have holidays will have something working, my packs aretaller than yours and I have no space to set 14S horizontally, so I think I will do 13s, not a big difference for 48v (44.2-53.3 range).

http://secondlifestorage.com/t-JAP-Just-Another-Powerwall-or-Jesus-Angel-s-Powerwall.

Regards

what's the exact size of your packs? And if you don't have enough space to put 14s horizontally, what about putting them vertically? Instead of using my design with horizontal busbars, you could mount them vertically...

Have sun!
Oliver

 

[jesusangel]

I've measured the packs and the wall and I must reconsider a little the installation place.

I had 2.2m at the end of stairs, my pack will be close to 20cms tall, so I have to move it a little. In proportion my packs use 2 more connection tabs every 20 cells. Where you have 7 packs I will have 14 half the taller of yours but double the tabs.

I will post on my thread an update to not mix my pictures with your installation.

http://secondlifestorage.com/t-JAP-Just-Another-Powerwall-or-Jesus-Angel-s-Powerwall?page=2

Thank you

 

[owitte]

ok, here're some more pics of how I build my packs, especially -but not exclusively - for jesusangel.

Each pack is made of 20 cells, average capacity is 2100mAh per cell/42Ah overall. Since I have a 7s configuration, a row of 7 packs is almost exactly 1kWh. Up to now, I have 12 rows, so it's 7s240p / 12kWh currently. There's still room for another 4 rows at the wall, so when complete, my powerwall will have 16rows, being 7s320p / 16kWh...

A battery holder consists of 3 pieces, these are the first two, made of 0.5mm brass plate:




The 3rd piece is the terminal connector, made of 15mm copper pipes:




































Then I solder all three pieces together for a nice holder:












Now it's time to prepare the 20-cells-pack, this is how the holders will be connected to it:








I use cheap chinese resistors, their legs have the right length for my packs and they make perfect fuse wires:
































At last I add 2 zip ties to fix the ends. This way, the weight will not be on the fuse wires, when I hang the pack to the wall:




Nice :






btw, does anybody could use a bunch of amputated resistors?




And this is how it finally looks at the wall:








Have sun!
Oliver

 

[Korishan]

Nice instructable!

 

[jesusangel]

Thank you, very well documented.

 

[owitte]

next update, another 140 cells, now 1820 cells overall, 260p7s, 13kWh. Also made new wall mounted busbars to connect my battery banks and inverter:









Next, I'll add some more solar panels, takes too long to charge now... . Will then post some pics from my solar installation.

Have sun!
Oliver

 

[jdeadman]

Nice wall.

 

[Stefaan De Ridder]

You are using resistorlegs as fuse.I like that idea.
Which type of resistor 1/4W or 1/8W?




Are all your packs of equal capacity? or only matching per added series string?

I have a lot of cell around 2000mAh, and also a lot of very decend 1350mAh cells(original 1500mAh)

So I was thinking to start making packs with matching 2000mA cells, and when powerwall is up and running, maybe add some 1350mAcell packs?

The modular design, with the busbars is something I want to try.

Smaller packs (so easier to handle and make) and slowly adding capacity, seems a bit more easy than the large 80p style packs.

best regards.

Stefaan