Stefanseiner
Member
- Joined
- Apr 16, 2020
- Messages
- 136
Hello,
my name is Stefan ( 37, from Germany) and after reading a lot at this wonderful board and watching tons of vids from HB and others at YT since the last few month I'd like to share my building progress with you folks, show my successes and my mistakes too.
The beginning:
in march this year finished my first installation of a photovoltaic at the summer house in my garden
My house is an 115 years old farmers house and the roof isn't very suitable for PV, therefor in the garden
In March and April I was pleased how much energy comes from the sun - and at the same time sad about how much energy will be "lost" during daytimes because of overproduction.
Plus: I already planed to increase the PV with some more modules on the firewood storage
The point I stumbled over a video on YT where a guy tinkers on old laptop batteries to build a solar powerwall at it's own - amazing :idea:
I decided to try building a 14s40p powerwall with about 3KWh to cover the base load of the house (250W).
My first idea was to buy some new chinese "Supercells" with 9.900mAh or even more for the powerwall. But the "Trustfire" in my DIY bluetooth speakerbox were a flop and my China batterie 18650 test - 508.800mAh in 62 cells showed that it's the same with other "brands".
So I decided to go with used cells from major brands.
I've done some researches on the internet where to get used 18650 batteries. In Germany this is really hard because of the battery recycling laws. In fact it is not allowed to electronicshops / bikeshops and so on to give used batteries away except to a qualified recycling companies. Btw: actual in Germany, "recycling" of LiIon cells means "burning" them down :-/
So I mailed and phoned round about 100 companies all over the country to get 6 !! positive answers from some ebike shops and some accurepair services. In two weeks I drove 4.500KM to collect them, but at all it was a good deal. All together I got something about 12.000 cells stuck together in different ebike akkupacks (40 - 60 cells in each pack).
Lots of time and work to dissasseble them
for testing I bought a LiitoKala Lii500 Engineer. Then another one. Then a XTar VC8 for pre-charging and 0V recovering (most defective eBike-akkus are 1-time deep-discharged because of an defective BMS, the batteries are still good and within a range of 90% or even more of the original capacity)
because I hate mussy cables next step was a charging station with an ATX power supply and some space left for even more chargers / testers
actual state for testing is: I pre-charge the cells atcheap 10-slot chargers while testing another lot of already fully charged cells in the 12 Liito Kala
I really like the XTar VC8 8-slot charger (middle, left), but they are not really cheap and handle a maximum of 300mA per slot, so I added 10 super-cheap chinesechargers (top row)
10 independent slots each at 0,6A cost round about 10 - 11 USD incl. shipping
Phomax 10 slot LiIon charger (the same from brand GTF)
quality isn't the best and I had already three defective charging pcbs,
but got three new chargers send out, took the bad pcbs out, replaced them with good ones and now have too functional chargers = 20 slots extra.
Should not be your first-use charging device but for fast bulk charging it's perfect - for me.
Oh, and they can do 0V reactivating as I tested, that's the first picture
To sort the cells by capacity and distribute them on equal packs I decides to use the Excel based RePackR and therefor I prepared an old IBM Thinkpad to use it into my garage / work shed
while processing the cells there were some works outside going on to build a terrace
within this works I did some cable works...
...from the house...
...to the firewood place - which got 8 JA-Solar modules each 340Wp. This will be the system for the DIY powerwall
electric housing with lightning-surgeprotection and an extra 400V connection for heavy equipment such as log splitter
the inverter will me mounted into the cellar of the house in a grid parallel mode. Just had to add an extra 5x 2,5mm wire
the place for the inverter. It will be an MPP solar / Infinisolar hybrid. Model unclear at this moment
still processing cells. At this time I sorted them by model into boxes to safe time when adding into the Excel based RepackR
but as my progress goes on, my plans with the total capacity grown too. Actual plan: build one test-powerwall to learn how to build them best, then build another one and get about 10KWh total.
At this time a decided to not use the Excel because of the huge among of time to fill all the data in. Instead I wanted to sort the cells into steps of 50mAh like HB have done with his huge powerwall (I think he used 100mAh steps)
So I bought 30 or 40 new plastic boxes. This are "Samla" from IKEA. I hate! this shop because I can't find out when I am in... Butr this boxes are perfect for 18650s. ~150pcs fit in the smalles 4L box (as on my first pictures above), ~350pcs in the bigger 11L box
costs me several days to sort the already processed cells into the 50mAh-boxes. I better had done this directly when took the cells out of the charger
short-circuit mistake. Just one of innumerable others... :s
after 30 or more different types of eBike akkupacks the best are definetely the ones from Bosch.
40 cells, very quick and easy to dissasseble, just high-capacity cells (LG MG1 with 2.850mAh minimum, mostly LG and Samsung with 3.500mAh), no glue and other shit between the cells, and every single akkupack of 130 I got in total was a defect at the BMS with cells in very good condition. No heaters, no dead cells, no water, no mechanical damage. Perfect for my use.
after the capacity-tests I checked the inner resistance with the well known Vapcell YR1030. But it's annoying to chek them laying on the table, rolling around so I builded a little helper-thing
now I can handle 150 cells
Timelaps video
I test them one by one and the bad ones (70mOhm or more) are pushed out a little bit, so when finished all cells I can sort them out for trash or other purposes
of course I had some cells which need a new heatshrink
purple is not my favorite colour, but I killed the complete stack of green shrinks within one unfocused moment while pan the heatgun :dodgy:
finally!! it's time to start the test-build
I am using the not-so-good laptop cells with round about 2.300mAh.
Laptop cells? In German internet forum you mostly can read about builds with laptop cells and how easy this is to disasseble, while eBike-akkupacks aren't easy to open and process, so I've given them a try and collected some laptop batteries from recycling companies.
to be continued
my name is Stefan ( 37, from Germany) and after reading a lot at this wonderful board and watching tons of vids from HB and others at YT since the last few month I'd like to share my building progress with you folks, show my successes and my mistakes too.
The beginning:
in march this year finished my first installation of a photovoltaic at the summer house in my garden
My house is an 115 years old farmers house and the roof isn't very suitable for PV, therefor in the garden
In March and April I was pleased how much energy comes from the sun - and at the same time sad about how much energy will be "lost" during daytimes because of overproduction.
Plus: I already planed to increase the PV with some more modules on the firewood storage
The point I stumbled over a video on YT where a guy tinkers on old laptop batteries to build a solar powerwall at it's own - amazing :idea:
I decided to try building a 14s40p powerwall with about 3KWh to cover the base load of the house (250W).
My first idea was to buy some new chinese "Supercells" with 9.900mAh or even more for the powerwall. But the "Trustfire" in my DIY bluetooth speakerbox were a flop and my China batterie 18650 test - 508.800mAh in 62 cells showed that it's the same with other "brands".
So I decided to go with used cells from major brands.
I've done some researches on the internet where to get used 18650 batteries. In Germany this is really hard because of the battery recycling laws. In fact it is not allowed to electronicshops / bikeshops and so on to give used batteries away except to a qualified recycling companies. Btw: actual in Germany, "recycling" of LiIon cells means "burning" them down :-/
So I mailed and phoned round about 100 companies all over the country to get 6 !! positive answers from some ebike shops and some accurepair services. In two weeks I drove 4.500KM to collect them, but at all it was a good deal. All together I got something about 12.000 cells stuck together in different ebike akkupacks (40 - 60 cells in each pack).
Lots of time and work to dissasseble them
for testing I bought a LiitoKala Lii500 Engineer. Then another one. Then a XTar VC8 for pre-charging and 0V recovering (most defective eBike-akkus are 1-time deep-discharged because of an defective BMS, the batteries are still good and within a range of 90% or even more of the original capacity)
because I hate mussy cables next step was a charging station with an ATX power supply and some space left for even more chargers / testers
actual state for testing is: I pre-charge the cells atcheap 10-slot chargers while testing another lot of already fully charged cells in the 12 Liito Kala
I really like the XTar VC8 8-slot charger (middle, left), but they are not really cheap and handle a maximum of 300mA per slot, so I added 10 super-cheap chinesechargers (top row)
10 independent slots each at 0,6A cost round about 10 - 11 USD incl. shipping
Phomax 10 slot LiIon charger (the same from brand GTF)
quality isn't the best and I had already three defective charging pcbs,
but got three new chargers send out, took the bad pcbs out, replaced them with good ones and now have too functional chargers = 20 slots extra.
Should not be your first-use charging device but for fast bulk charging it's perfect - for me.
Oh, and they can do 0V reactivating as I tested, that's the first picture
To sort the cells by capacity and distribute them on equal packs I decides to use the Excel based RePackR and therefor I prepared an old IBM Thinkpad to use it into my garage / work shed
while processing the cells there were some works outside going on to build a terrace
within this works I did some cable works...
...from the house...
...to the firewood place - which got 8 JA-Solar modules each 340Wp. This will be the system for the DIY powerwall
electric housing with lightning-surgeprotection and an extra 400V connection for heavy equipment such as log splitter
the inverter will me mounted into the cellar of the house in a grid parallel mode. Just had to add an extra 5x 2,5mm wire
the place for the inverter. It will be an MPP solar / Infinisolar hybrid. Model unclear at this moment
still processing cells. At this time I sorted them by model into boxes to safe time when adding into the Excel based RepackR
but as my progress goes on, my plans with the total capacity grown too. Actual plan: build one test-powerwall to learn how to build them best, then build another one and get about 10KWh total.
At this time a decided to not use the Excel because of the huge among of time to fill all the data in. Instead I wanted to sort the cells into steps of 50mAh like HB have done with his huge powerwall (I think he used 100mAh steps)
So I bought 30 or 40 new plastic boxes. This are "Samla" from IKEA. I hate! this shop because I can't find out when I am in... Butr this boxes are perfect for 18650s. ~150pcs fit in the smalles 4L box (as on my first pictures above), ~350pcs in the bigger 11L box
costs me several days to sort the already processed cells into the 50mAh-boxes. I better had done this directly when took the cells out of the charger
short-circuit mistake. Just one of innumerable others... :s
after 30 or more different types of eBike akkupacks the best are definetely the ones from Bosch.
40 cells, very quick and easy to dissasseble, just high-capacity cells (LG MG1 with 2.850mAh minimum, mostly LG and Samsung with 3.500mAh), no glue and other shit between the cells, and every single akkupack of 130 I got in total was a defect at the BMS with cells in very good condition. No heaters, no dead cells, no water, no mechanical damage. Perfect for my use.
after the capacity-tests I checked the inner resistance with the well known Vapcell YR1030. But it's annoying to chek them laying on the table, rolling around so I builded a little helper-thing
now I can handle 150 cells
Timelaps video
I test them one by one and the bad ones (70mOhm or more) are pushed out a little bit, so when finished all cells I can sort them out for trash or other purposes
of course I had some cells which need a new heatshrink
purple is not my favorite colour, but I killed the complete stack of green shrinks within one unfocused moment while pan the heatgun :dodgy:
finally!! it's time to start the test-build
I am using the not-so-good laptop cells with round about 2.300mAh.
Laptop cells? In German internet forum you mostly can read about builds with laptop cells and how easy this is to disasseble, while eBike-akkupacks aren't easy to open and process, so I've given them a try and collected some laptop batteries from recycling companies.
to be continued
