36 hub motor and bird 2 battery

[galenshanks]

I have been wanting to build an ebike for awhile and have acquired a bird 2 battery pack 36v 7800ah with lg m71 cells and was wondering if it, along with a 36v hub motor on a 26" rim would be adequate or merely a waste of time

 

[neptronix]

How fast do you want to go? that battery is quite small and probably only good for 15-20mph.
I can't find any reference to a LG M71 cell online.

 

[galenshanks]

I'm sorry they are lg mj1 cells.60 LG MJ1 18650 Cells in a 36v 756Wh 21000mAh 10s6p pack.I purchased it used from batteries clearing house for $60. Like all other bird 2 packs the controller is built into the bms so I had to jump the p+ to the b+.I don't need a racing bike, but don't want to be one of those people who get suckered into spending money over and over for minor gain, but I'm not educated enough in the ebike scene to have experienced how this works and that works. I'm just now trying to wrap my head around the controller is what offers the amperage and the motor and battery just go along with it as long as the motor isn't abused to the point of overheating. To go around town at a steady pace of @ 45mph would be amazing to me. I hate to bother you but can you give me a combination that could make that possible. What kind of controller at what voltage and amperage coupled with what wattage motor i could lace up in a 26" wheel and just what voltage and ah battery pack for around a 5 mile trip to and from work daily. Thanks for your attention on this and if it's asking too much I completely understand. I don't have a lot of baground in electronics but I have been a mechanic for over 35 years so I got a little sense.

 

[galenshanks]

C

I'm sorry they are lg mj1 cells.60 LG MJ1 18650 Cells in a 36v 756Wh 21000mAh 10s6p pack.I purchased it used from batteries clearing house for $60. Like all other bird 2 packs the controller is built into the bms so I had to jump the p+ to the b+.I don't need a racing bike, but don't want to be one of those people who get suckered into spending money over and over for minor gain, but I'm not educated enough in the ebike scene to have experienced how this works and that works. I'm just now trying to wrap my head around the controller is what offers the amperage and the motor and battery just go along with it as long as the motor isn't abused to the point of overheating. To go around town at a steady pace of @ 45mph would be amazing to me. I hate to bother you but can you give me a combination that could make that possible. What kind of controller at what voltage and amperage coupled with what wattage motor i could lace up in a 26" wheel and just what voltage and ah battery pack for around a 5 mile trip to and from work daily. Thanks for your attention on this and if it's asking too much I completely understand. I don't have a lot of baground in electronics but I have been a mechanic for over 35 years so I got a little sense.

Also I don't know if it's going to make a difference but for I guess there's no such thing as too much information. I have in mind to purchase one of those huffy beach cruisers as a foundation and not to worried about the various unnecessary things such as brake switches, pedal assist, theft deterrent...et cetera. Just a thumb throttle and and possibly a digital screen to change speeds if necessary and power on and off. Is it even possible to accomplish this with a a 500w hub motor or it's going to take a $500 motor? I promise if you guys on here can put with me for a little bit I will pass what I have been taught to the next new guy. I became addicted to this stuff when I was given a walmart city bike that barely pulled itself out of its own tracks. I'm so ready to go fast relatively speaking.

 

[galenshanks]

C

Also I don't know if it's going to make a difference but for I guess there's no such thing as too much information. I have in mind to purchase one of those huffy beach cruisers as a foundation and not to worried about the various unnecessary things such as brake switches, pedal assist, theft deterrent...et cetera. Just a thumb throttle and and possibly a digital screen to change speeds if necessary and power on and off. Is it even possible to accomplish this with a a 500w hub motor or it's going to take a $500 motor? I promise if you guys on here can put with me for a little bit I will pass what I have been taught to the next new guy. I became addicted to this stuff when I was given a walmart city bike that barely pulled itself out of its own tracks. I'm so ready to go fast relatively speaking.

Guess I asked too much. Always was picked last and the sad part is I was a hell of a ball player. I guess that was a hint...lol

 

[neptronix]

Well if you want some feedback..
I have a hard time reading your requests because they don't have paragraph breaks and a lot of unrelated things.. i also run 2 companies right now so my time is limited to reply.

Give me a simplified, short version of this question and i'll give you an answer... or your money back

ps if your battery is really '36v 756Wh 21000mAh', then there's probably room to push 1kw continuous even if you got wimpy cells, so 25-30mph shouldn't be off the table.

 

[lnanek]

Grin has a motor simulator that would give you a top speed.

To calculate manually, every motor has a kv rating that tells you the RPM per volt. You can then take your wheel size to turn RPM to distance per minute. Then covert your speed to mph. 36V is very low, so I wouldn't expect high top speed even though big wheels would help.

At 48V with a 30A controller, my "750W" rated motor can't break 30mph on my 20" fat tire bike.

Even once you calculate your top speed, you then also need to pump in enough amps to get enough torque to fight the wind resistance, and that gets higher faster the faster you go.

 

[mindgames11]

I'm sorry they are lg mj1 cells.60 LG MJ1 18650 Cells in a 36v 756Wh 21000mAh 10s6p pack.I purchased it used from batteries clearing house for $60. Like all other bird 2 packs the controller is built into the bms so I had to jump the p+ to the b+.I don't need a racing bike, but don't want to be one of those people who get suckered into spending money over and over for minor gain, but I'm not educated enough in the ebike scene to have experienced how this works and that works. I'm just now trying to wrap my head around the controller is what offers the amperage and the motor and battery just go along with it as long as the motor isn't abused to the point of overheating. To go around town at a steady pace of @ 45mph would be amazing to me. I hate to bother you but can you give me a combination that could make that possible. What kind of controller at what voltage and amperage coupled with what wattage motor i could lace up in a 26" wheel and just what voltage and ah battery pack for around a 5 mile trip to and from work daily. Thanks for your attention on this and if it's asking too much I completely understand. I don't have a lot of baground in electronics but I have been a mechanic for over 35 years so I got a little sense.

If I were you I'd rip apart that big flat battery pack with the jumpered bms and reconfigure the pack as a 13s4p in a shape that has less surface area.
The bike I use most has a 20" cast wheel with a DD motor that was something like $150 on amazon and I use an $18 chinese controller from aliexpress. that easily goes about 25 mph.
I have a 700c bike with a DD hub and a 52v battery that I haven't topped out because I'm frightened.