the "this sounds like a fun project" powerwall (in Belgium)

wimpie007

Member
Joined
Apr 8, 2017
Messages
81
Hi everyone!

After discovering the youtube channels around june 2017 and this forum shortly after, it's now finally time to show what I've been able to do so far...
I enjoyed the idea of reducing my power costs by going solar, but most of my usage is not during the day so battery storage sounds like the ideal solution.

I started out collecting laptop batteries, but quickly found that a lot of them have quite a number of cycles on them and they'd show only a small capacity remaining.
Since I live near the border of Belgium and The Netherlands, 2 nice flat countries with lots of people using e-bikes, I started doing the rounds at the bicycle shops.
I've collected quite some packs, given away some as well...

I also built sort of a "charger board", mostly because I modded the OPUS chargers with 80mm fans.
It's powered by an old computer power supply and has 12 TP4056's for charging, 4 slots for reviving 0 Volt cells and 3 OPUS C3100's (3 slots have died, unfortunately).

image_hjtwqm.jpg

image_ecfomp.jpg

image_dendhc.jpg


After about 1,5 years I managed to gather2266 cells anda little over 1700 of them are 2000 mAh or more in capacity.
It took a while, at first 1 wanted 80P packs and then a 100P and.... :D Now I've settled for 60P, but built 28 of them rightfrom the go.
After using repackr, I had the values to go in each pack but some late nights later it seems I've made quite a few errors along the way.

image_uzfnls.jpg
->
image_iencwp.jpg
->
image_gliybc.jpg

So 28 packs on the table, each 136,3 Ah which gives 14 kWh.
I've also purchased:
  • a MPP Solar PIP-5048GK (the latest edition)
  • an ABB 160A DC breaker (eBay link)
  • 35 mm cable to go between battery and inverter
  • A Batrium WatchMon4 suite to complement it all
  • solar panels to come when the battery system is operational
I've only completed the packs right now, so I can keep you all updated with the next steps coming up...
Thanks for reading!
 
Great start,
I'm looking forward to seeing your build progress.
 
Good job, looks like you had the mats to actually make complete slots on the custom charger.
Make sure to monitor the PSU voltage, as it can drop quite a lot if you have many bad cells charging in the same time.
 
Hi, how did it go with the DC breaker, does it have a shunt trip, does it work ok with batrium watchmon?
Please share your experience with it, since a friend is considering it for his powerwall. Thanks
 
Hi Frnandu, I have to admit that I haven't tested it with the Batrium yet (because that isn't set up yet).
The DC breaker has the auxiliary shunt trip, which is rated at 50 VA on 24 to 40 Volts. I have bought a dedicated 60W 24V psu to provide power for it to trip and that works very well.
So depending on the voltage in your powerwall, you could use it directly off 24V, but since I was going for 48V I had to take this side step.
Here's a photo (from the seller):image_hjzkgf.jpg


This is the breaker I've got:ABB Sace TMAX T1D 160 PV 1100V DC 160 A 4-pole circuit breaker
 
wimpie007 said:
Hi Frnandu, I have to admit that I haven't tested it with the Batrium yet (because that isn't set up yet).
The DC breaker has the auxiliary shunt trip, which is rated at 50 VA on 24 to 40 Volts. I have bought a dedicated 60W 24V psu to provide power for it to trip and that works very well.
So depending on the voltage in your powerwall, you could use it directly off 24V, but since I was going for 48V I had to take this side step.
Here's a photo (from the seller):image_hjzkgf.jpg


This is the breaker I've got:ABB Sace TMAX T1D 160 PV 1100V DC 160 A 4-pole circuit breaker

Thanks Wim,

I'm using a ABB S5N 300A for a year now, and the shunt trip it's connected to the middle of my 14s battery (7s should fit the voltage spec of the shunt trip), and relay'ed by the watchmon. Since this is NO and only uses power when triggered, very briefly I consider this to be ok, with no need for external power.

I'm asking about your model for a friend who is searching for a similar breaker.
 
FrnanduMarti?ski said:
... the shunt trip it's connected to the middle of my 14s battery (7s should fit the voltage spec of the shunt trip), and relay'ed by the watchmon. Since this is NO and only uses power when triggered, very briefly I consider this to be ok, with no need for external power....
Actually, I could have done that as well... :s :-/ Well, I might do it that way after all, the 24V power supply was only a few .

An update then:
Starting with a small facepalm-moment, since I'm watching this great YouTube video from Average Joe again after making all the busbars.
I ended up cutting and stripping about 170 meter (= 185 yards) of 2,5mm solid copper wire. But I forgot to straighten them out, before twisting them together. So while some look pretty clean, most have a few kinks in them. Oh well, the copper is still there, that's what's most important. :sleepy:

So using a mock-up I bent the twisted wire into shape. I chose to come down at an angle, because I plan to stack 2 60P packs on top of each other.

image_ojnrqz.jpg

This might be not ideal, but I kind of drove myself into a corner by ordering only 14 longmons and then deciding I was going for 28 (60P) packs instead of the 14 (100P) packs like originally planned.

What's planned for the rest of the weekend? Not too much, since I have to work late shifts. I'm going to re-sleeve some of the cells with a damaged outer wrap/sleeve.
Running through my options of attaching the busbars to the packs (hot glue, cable straps, ...?).
I hope to start soldering on monday, if the weather allows it since I'd rather do this outside. I'm guessing that will eat up quite some time.
Still left to decide:
  • How to attach the busbars
  • using 1A or 0,5A fuses. I have a 1000 of both of them.
  • Only fusing the Positive connection, or double fusing?
  • Using wood or metal shelves to store the battery packs or rather a metal filing/archive cabinet to keep everything out of sight (might also be easier for adding fire safety measures later)
Your thoughts? :huh:
 
  • Like
Reactions: wim
Zip ties (go through the pack)
0,5A (they do pop a bit higher)
Positive only (resistance)
Metal shelves.... a cabinet is even better (more fire resistant than wood)

Have fun :)
 
Hey (fellow) Wim, I should give you credit for the cabinet idea :D
I like it a lot because of the safety with kids around and the possibility to install fire suppressing material in it. Still looking into this...
I'm trying to fine one that will fit in the space I have, but that's only about 1m high.
It should also be 1,2m in width if I want to mount the 14S side by side. Proving to be bit of a struggle.
Now leaning towards using an Ikea PS:
image_bumbeb.jpg
 
Already an idea on the fire suppressing material you plan on using?
 
To be honest... No :(
I've been between soldering like a madman, some other hobbies, work but most importantly some illness in the family for the last few weeks.

I completed pack 1 - 14 like 2 weeks ago, but haven't found the free time to start setting it all up yet.
I have some last parts coming in on Tuesday for the changes to my electrical distribution board.
Solar panels are also on the way, will be another 2 weeks or so...

I'm leaning towards constructing my own shelves, while keeping an eye out for a suitable cabinet.
There is still some discussion ongoing with my wife about the location of the batteries themselves, being either inside in the attic or outside on our terrace (in some weatherproof housing).

I'll certainly order some extra smoke/fire detectors to go inside the battery room/cabinet.
Do you have some recommendations, @bvh?
 
So, it's been a while since I had anything to share...

But the powerwall is finally up! :cool:
For safety reasons, the batteries were moved out of the house, so I got myself a shed... Turns out it's Australian :D
I added some XPS insulation to keep the temperatures within reasonable levels.

image_fxrndc.jpg
image_rcjuva.jpg
I mounted the PIP5048-GK to a board, together with the ABB breaker, the batrium system and the distribution box.
It's ugly and I'll probably redo it but it works for now.
14S 60P for now, 136 Ah per pack. I have another set of 60P packs that still need soldering.

image_jwepva.jpg


image_quamty.jpg

And a view of the makeshift shelves with the monitoring computer on top.

Still needed:
- Moar batteries! So, soldering the next 14 packs.
- Adding a spare pack. Right now the powerwall is down because of some blown fuses on pack #3.
- Providing some more space to work inside the shed.
- Tidying up the cables and adding a network connection. The PIP5048GK has bluetooth connection, but the range is abysmal because it's in a metal shed.
- Adding more house load when the extra packs are in place. I'm limited to +/- 30A on the powerwall right now because of the 60P with 0,5 A fuses.
- Replacing some filament LED bulbs inside the house. The flickering from the PIP inverter is quite bad, makes you nauseous. LED bulbs with power electronics don't have this problem.

Any thoughts, remarks?
 
I was making the connections between the packs with nuts and bolts and I used a ratchet wrench with an extension.
I touched the next bolt, creating a short over the pack # 3 and 4. On pack 4 I had 58 out of 60 fuses blown, on pack 3 I had 19 blown.

Regarding the size of the shed: if I manage to get cells in a similar range for the next packs, then I'd be able to fit 42 kWh on this shelf and I have room to add a second one just like it.

I'll get the powerwall back up this weekend and I've started soldering packs 15 - 28. :p
 
Hi Wimpie007 :)

In a previous post You wrote: "After using repackr, I had the values to go in each pack but some late nights later it seems I've made quite a few errors along the way."

Here is an idea You are free to use:

Collect all the cells for one complete cell bank (f.eks. 60 x 14 cells in Your case)

Now sort all the cells in capacity, hi to low.

Next ready the cell holders, all 14 of them:

Use the cells from the high capacity end.

Populate cell 1 in each cell bank from left to right with the first 14 cells, next populate cell 2 from right to left, cell 3 from left to right, and so on, until all 840 cells are placed.

(When You have placed the first 14 cells #14 may be a few mAh lower in capacity, however by reversing the direction of mounting #28 will be placed next to #1, #27 next to #2, cancelling the differences in capacity.)

Now You have 14 cell banks with equal capacity, give or take 1%.

Only disadvantage: It is hard not to start making the cell banks until You have collected 840 cells :)

Best of luck with Your build.

ChrisD
 
This it how Daromer/DIY Tech & Repairs has built several of his packs, and even has videos showing the progress. And his packs/strings have been running for several years now
 
I probably lost some time when messing around in Excel to get the measurement data in, but it seemed like a logical way to keep track of what I had.

If I didn't have all the data, I would have settled on 80P packs or even 100P packs, before I realized I had enough good cells to go for 2 x 60P.
Having found some cells I felt unsure about after building the packs, I've replaced some with similar capacity ones that I had left over.
So if I start building packs again, I'll first have to do an inventory of what I still have...

The choices we make early on, can carry through for quite a while ;)

Quick question, how do you guys monitor the PIP inverter?
Through USB permanently connected?
 
ChrisD5710 said:
Hi Wimpie007 :)

In a previous post You wrote: "After using repackr, I had the values to go in each pack but some late nights later it seems I've made quite a few errors along the way."

Here is an idea You are free to use:

Collect all the cells for one complete cell bank (f.eks. 60 x 14 cells in Your case)

Now sort all the cells in capacity, hi to low.

Next ready the cell holders, all 14 of them:

Use the cells from the high capacity end.

Populate cell 1 in each cell bank from left to right with the first 14 cells, next populate cell 2 from right to left, cell 3 from left to right, and so on, until all 840 cells are placed.

(When You have placed the first 14 cells #14 may be a few mAh lower in capacity, however by reversing the direction of mounting #28 will be placed next to #1, #27 next to #2, cancelling the differences in capacity.)

Now You have 14 cell banks with equal capacity, give or take 1%.

Chris, this is exactly how I did it.....worked fine for me.
 
@Franky: Please move your replies outside of the quote block. I have no idea where Chris' comments are and where yours are. You can make multiple quote blocks if commenting on different parts.
 
Back
Top