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Powerwall Journey with reused e bike cells ( 20 kwh )
#1
Hello everyone,

first of all something about me. I am here since i saw a youtube video from Peter Metthews and thaught never ever will it be true.
So i got one "dead" ebike battery for free and tested it. Less then 10 % missing power and i thaught  ok i will do it too.  Big Grin

I am not a electrican person,  so i have to learn alot but the house part with all the wires a friend will help me. 
But i want to learn as mutch as i can since i wanted to be electrican in when i was a child. But became programmer Wink


Right now i have 30 kwp Photovoltaik at my roof and a Tesla Powerwall 2 (13,5 kwh) running. I am living in germany and from march to October i am 99 % off grid.

Plan:

Add a new 10-15 kwp system just to south, for the new battery and to be in the winter also at 70 % off grid.
Building a 20 kwh Battery for storage.



Setup , so far as i read in here , will be done with:

10 kw 3 phase hybrid MPPT Inverter 48 V 
Battrium 
Rack to store all the batterys

How it looks like right now:



Tools i made myself:

Thanks to average joe





Questions right now are : 

My Rack is 80 cm long, 60 cm witdh and 100 cm high. What is the best setup for the Batterys. i dont wanna waste alot of space in the rack.  I could make a shelf and make them close to 240p = around 60 cm length. idk so far what will be the best way.

I wanna build a very "safe" system since it will run in my cellar. So i just would like to get the batterys charged and discharged with 500 mA and not more.  

If i understood in the mppt manual i can set the current and need to calculate my battery that i will just charge and discharge my system by 500mA . Is this true ? 


Happy to be here

If there is a chat somewhere i can ask questions and google alot i also would like to know. 

thanks

caos
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#2
Hallo und herzlich Willkommen :-)

Nice Project, in Germany its very popular to get and recycle eBike Batterys for free :-)
From my view much better than laptop batterys.

The safe way is always good.
You can set max charge / discharge in Batrium, also critical values for shut down the system.
2013: 40x PhonoSolar 250Wp @SMA Tripower 10000 || 2016: LG Chem RESU 12kW @SMA SunnyIsland 4.4 || 2019/20: DIY POWER :-)
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#3
Have a look at some of the other projects and those with youtube Vids are great. With that inverter you will want to run 14s for liion or 16s for Lifep04 cells.

Have a look at Dromer's Channel as he has some experiences with that 3 phase inverter.

Cheers
******Hi My name is Jason and I have SOCD (Solar Obsessive Compulsive Disorder)*******
Current Powerwall - 1400 Cells 7s200p (modular 40p packs) ~ 12kWh of storage     4x 315W Canadian Solar Panels

Working on the next 7s40p packs     ~2.5kWh

Waiting on 2000 Cells of unused Sony vt4 (2000mah 30A) ~ 15kWh      hehehehehe  More Power
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#4
Hi everyone,

last week i hopefully finished my coming batterie design.

i tryed to use daromers youtube video for some calculations:


Cap: 2500 mAh
 
14s = 14 x 3,7 V = 51.8 V
 
3 x 6 Battery Holder = Space for 360 Cells

 

 360 / 14 = 24 Parallel    = 14s 24p

i would like to copy the pack design with busbars etc. from jehugarcia. Daromer als did a 48 Volt Pack Design but i more like the easy way of jehu.
Idk about the electrical diverence but when i just look in pack building it looks more easy.

 


 

Wh:

2,5Ah x 24= 60 

60 x 3,7 = 222 ah
222 x 14 = 3.108 wh


With this long pack i use the depth of my rack very good. 

Now i need to understand if this huge amount of batteries and amps is ok or far to mutch.

Any suggestions are welcome 

thanks

Nils






Bestätigt
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#5
For What hour you take the Ah and multiply it by the average voltage you will be running. So for a Pack that has 14s of 2.5Ah cells each Parallel Set will be 60Ah then take your Voltage for a 14s set you will generally run 3.5V/cell to 4.1V per cell or 49V to 57.4 you take those 2 numbers and add them up then divide by 2 you will get 53.2V
Now 53.2 x 60Ah = 3192 or 3.19Kwh
caosmen likes this post
******Hi My name is Jason and I have SOCD (Solar Obsessive Compulsive Disorder)*******
Current Powerwall - 1400 Cells 7s200p (modular 40p packs) ~ 12kWh of storage     4x 315W Canadian Solar Panels

Working on the next 7s40p packs     ~2.5kWh

Waiting on 2000 Cells of unused Sony vt4 (2000mah 30A) ~ 15kWh      hehehehehe  More Power
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#6
Thanks alot jdeadman. like i said just used daromers calculation but i understand why you do it that way.

thanks for the reply
jdeadman likes this post
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