johnnyz
1 kW
Hey there...thought I would post some pics, data, video (on Youtube) about my battery extender I am in the final phases of testing.
I looked at the current product available and did not like what I saw so I decided to make my own. I purchased the cells and BMS from a vendor on Alibaba that I have known for 5 years and who I trust. I ordered a couple hundred EVE 18650 cells rated at 2550 and a nice 100 AMP BMS.
.
I decided to design a case and battery holders to make a 16s 7p arrangement as compact as I could, so as to be as aesthetically pleasing as I could...well..didnt turn out exactly as I planned but will redo as soon as I am able..
Started out with pressboard...
Then I 3d printed the case in pieces and the cell holders....
The 2 reasons I decided on this was because I wanted more range (I was getting about 45-50 kms and less if I maintained 50 kph...also I ordered a BAC 4000 and wanted to up the power level and new from experience that Panasonic PF cells were at best a 10 amp cell and at 135 amps, I was over the design of the cell.
The EVE cells were tested first for capacity
and the first random 5 cells were all in the 2600 range with resistance of about .035moh...so far so good...
Heres what the pack looked like ready to be welded together...
I used Lepage Super glue to glue the pieces of the case together....
Now, when putting the pack together, I decided as I had said to weld the packs with nickle strip but on the series connections I soldered a thick piece of 10 gauge solid core copper and then welded this to the next cells in series..
I soldered 2 of these between the series connections.
This is what the arrangement looked like in the case...
I then doubled up the 10 G wire for the Pos and Neg wires...
I miscalculated the end of the battery back where the BMS was to reside and the BMS was actually sticking out the end...so I had to make an extension of the original piece to cover where the BMS was
I also incorporated the light on the Surron to the back of the case..
Ok..onto to the Surron battery...I did the BMS bypass of the load side myself...
Heres a pic of the case under the seat and mounting points...I tapped the first and last holes and made an aluminum strap to hold the pack...
How the pack would have looked...but had to modify the back for extra length and I had to increase the thickness a bit to accomodate everything inside...
Heres the battery on the bike...
And the connection to the Surron battery via a parallel connect...
There is a lot of tidying up of little things but I wanted to get to the testing so that will come last...heres the bike as it looks with the pack on the back...
Since there would be clearance issues I simply put a polyurethane bushing in the shock to limit the travel..
Ok...the results...I had Teznic tune the BAC4000
to just under 8000 watts..in this case 8000 watts...Ive increased the range to about 75 kms..thats at 45 kph steady, if I putter around the little village I live in I would get 100 km distance...I have the Cycle Analyst attached and it is showing me under full throttle about 6 volts of sag and most importantly between .035 and .040 moh of resistance...Top speed has increased from 68 KPH to 90 KPH...
this is with 2 batteries together which have similar capacity, C rating and resistance...The Surron battery with stock controller sagged 6 volts at 80 amps...it would probably sag around 8 volts at least with this kind of power upgrade, then being over the design limits of the cell.
I have a youtube video of this and am going to include more youtube videos of this bike...(https://youtu.be/rRVPTcCcjpA)
I looked at the current product available and did not like what I saw so I decided to make my own. I purchased the cells and BMS from a vendor on Alibaba that I have known for 5 years and who I trust. I ordered a couple hundred EVE 18650 cells rated at 2550 and a nice 100 AMP BMS.
.I decided to design a case and battery holders to make a 16s 7p arrangement as compact as I could, so as to be as aesthetically pleasing as I could...well..didnt turn out exactly as I planned but will redo as soon as I am able..
Started out with pressboard...
Then I 3d printed the case in pieces and the cell holders....
The 2 reasons I decided on this was because I wanted more range (I was getting about 45-50 kms and less if I maintained 50 kph...also I ordered a BAC 4000 and wanted to up the power level and new from experience that Panasonic PF cells were at best a 10 amp cell and at 135 amps, I was over the design of the cell.
The EVE cells were tested first for capacity
and the first random 5 cells were all in the 2600 range with resistance of about .035moh...so far so good...Heres what the pack looked like ready to be welded together...
I used Lepage Super glue to glue the pieces of the case together....
Now, when putting the pack together, I decided as I had said to weld the packs with nickle strip but on the series connections I soldered a thick piece of 10 gauge solid core copper and then welded this to the next cells in series..
I soldered 2 of these between the series connections.
This is what the arrangement looked like in the case...
I then doubled up the 10 G wire for the Pos and Neg wires...
I miscalculated the end of the battery back where the BMS was to reside and the BMS was actually sticking out the end...so I had to make an extension of the original piece to cover where the BMS was
I also incorporated the light on the Surron to the back of the case..
Ok..onto to the Surron battery...I did the BMS bypass of the load side myself...
Heres a pic of the case under the seat and mounting points...I tapped the first and last holes and made an aluminum strap to hold the pack...
How the pack would have looked...but had to modify the back for extra length and I had to increase the thickness a bit to accomodate everything inside...
Heres the battery on the bike...
And the connection to the Surron battery via a parallel connect...
There is a lot of tidying up of little things but I wanted to get to the testing so that will come last...heres the bike as it looks with the pack on the back...
Since there would be clearance issues I simply put a polyurethane bushing in the shock to limit the travel..
Ok...the results...I had Teznic tune the BAC4000
to just under 8000 watts..in this case 8000 watts...Ive increased the range to about 75 kms..thats at 45 kph steady, if I putter around the little village I live in I would get 100 km distance...I have the Cycle Analyst attached and it is showing me under full throttle about 6 volts of sag and most importantly between .035 and .040 moh of resistance...Top speed has increased from 68 KPH to 90 KPH...this is with 2 batteries together which have similar capacity, C rating and resistance...The Surron battery with stock controller sagged 6 volts at 80 amps...it would probably sag around 8 volts at least with this kind of power upgrade, then being over the design limits of the cell.I have a youtube video of this and am going to include more youtube videos of this bike...(https://youtu.be/rRVPTcCcjpA)
