new ebike build...

[bike4life]

It works... its 24 series of 22650 lifepo4... Right now i tested the ebike at 78 volts pack voltage and it only went 30mph... Each bank of cells is 39 volts and i have 2, one on left. other on right. 39 x 2 = 78. Slight dissapointment... I have a 48v / 72v controller... Maybe either the controller is dumb and messing up... I think maybe the full charge voltage on these sells is 44 volts, so 44 x 2 = 88 volts... I am currently charging the banks with my server psu, 3 in series, to 36 volts, running through boost converter to step up to 44v (there are 4 psu in the picture but the last one isnt plugged into anything or hooked up. My BMS system is clip on with alligator clips as i was to cheap to buy 2 bms, so just clip on one and then unclip and clip on battery number 2...

I hope it goes 45 mph... It really should considering the high voltage i am running... I also tested the battery against some kiln wire and it was able to put out 20amps with my clamp meter, so 44 v 20 = 880 watts. I am sure if i did a lower resistor it would have put out ever more amps... These cells can put out like 10 C, so i dont really know why its going so slow...

cell spec sheet:

https://www.buya123products.com/uploads/vipcase/844c1bd8bdd1190ebb364d572bc1e6e7.pdf

each battery bank was 55 dollars from batteryhookup.

 

[bike4life]

Update 2:
BMS cuts out during charging... I cant charge to 45 volts (max capacity). Only 42.5... The BMS cuts off and the current flowing to the battery drops to 0 measured via dc clamp meter. If i bypass the bms, the thing still charges... Why? Because looks like i have a few cells at 4 volts while others are at 3.5 during charging... hmmm... Is the BMS like going to balance those will that take time, and then the charger will turn back on? thoughts....
Or maybe i should call it a lost cause and stop charging at 42.5

Each psu is actually taped and i put wood shims on top of them and they go in between so the metal case of the psu would not touch, so they all dont share a common ground... i also use a 2 prong plug so they are not grounded which is good cause otherwise i heard you cant combine them in series, it just goes to ground.

Also i am a little confused. I have 3 500 watt server psu... Yet when charging only like 3.xx amps x 45 volts = 150 watts goes through.. Maybe its cause they are like somewhat charged and not empty... maybe when i drain these batteries to empty after riding around, the server psu will deliver like 800 watts charging hopefully!!!!

 

[bike4life]

Edit 2:

Usually this thing now after wiring something to the controller, maybe a slight increase in speed to 33mph average...

On flats and no wind, the record speed was 42 mph after like 30 seconds of acceleration... Very nice...

on hills going up, i was suprised, as it only does like 27... Somehow the lifepo4 pack should be dumping lots of amps given the 30C rating, idk, maybe i need a shunt mod on the controller, thats prolly it. These batteries come with a sticker of max current 800 amps... its crazy then why its not going faster. Ex. 8 cells in parallel x max discharge 100 (60 C pulse, 30 C continous, 1 C is 2.5a) amps each = 800+ amps...

Edit 3: I need to do a range test... i need to compare the range of this guy to my old ebike.
Edit 4: I wonder if i can charge both batteries simultenously in parallel... I got server power supplies so it should handle it...
Edit 5: Genius ebike idea.... Put a diesel 000watt generator on a trailer and buy a few server power supples to make DC... Then hook the DC output from server psu to ebike controller... Infinite range diesel electric bike. I am definetly going to do that sometime....

 

[bakaneko]

Edit 2:

Edit 5: Genius ebike idea.... Put a diesel 000watt generator on a trailer and buy a few server power supples to make DC... Then hook the DC output from server psu to ebike controller... Infinite range diesel electric bike. I am definetly going to do that sometime....

i did it (integrated into frame) and wouldn't do it again. its unique but ultimately flawed as battery becomes bigger and less expensive. well, who knows maybe you can do it better. here is what i did; i posted the build here and on my yt channel. this was like last year and then the batteries went to crap. it had nice range indeed but i mean the noise...

 

[HumanPerson]

@bike4life Do not ever let anyone tell you that you cannot do something...do you hear me?

 

[bike4life]

@bike4life Do not ever let anyone tell you that you cannot do something...do you hear me?

thanks HumanPerson... I'll drink to that....

I would also add on, dont let yourself tell you that you cannot do something....