Two Batteries!!! How Do I Wire Them??? PLEEEEASE HELPPPP!!!!!!

[MagneticMotorE]

how do I wire two batteries together to become one large battery storage while running to motors off the same system?

do I wire them in "SERIES"? if so, how do I do that?

I have a (Dual Motor) Bike Kit on my Cruiser Bike (Click Link Below) "Must be signed in Facebook to View Page"

https://www.facebook.com/media/set/?set=a.164117930358645.21631.100002813180250&type=3

there both wired to a terminal block allowing me to use both motors at the same time but i'm worried if I add another battery in series, it would be a problem...


PLEASSSSSSSSSSSSSSE HELPPPPPPPPPPPPPP!!!!!!!!

[csm]

https://www.facebook.com/media/set/?set=a.164117930358645.21631.100002813180250&type=3

Nice ebike setup you have there. Would like to know more about what you have as front motor and controller for front wheel.. and how you are wiring it up with your Magic Pie in the rear. Is that a magic Pie 2 or 3?? Are you using the internal controller for the Magic Pier or are you bypassing to an external controller??

[MagneticMotorE]

I'm using a 60 amp terminal block to conjoin both motors to one battery...

I'm able to use both throttles at the same time... Very Nice! LOL!

I Have The Magic 2 (External Controller)

I myself am trying to find out how to add another battery wired in "series" to the terminal block.

im choosing series so that the voltage stays the same instead of wiring in "parallel" which will double the voltage and fry the motors. LMFAO!!!

[Bikemad]

im choosing series so that the voltage stays the same instead of wiring in "parallel" which will double the voltage and fry the motors.

I think you meant parallel instead of series.

The following diagram should help to clarify the difference between series and parallel configurations:


Wiring two identical batteries in series will double the voltage but will still have the same capacity (Ah).

Wiring two identical batteries in parallel will double the capacity (Ah) but will still have the same voltage.


You can connect identical voltage packs of different capacity in parallel, but only if they are the exact same voltage and chemistry. So it's not a good idea to put a 36V LiFePO₄ pack in parallel with a 36V Li⁴Mn₂ pack because their actual voltages will be slightly different.

Before you connect battery packs in parallel, you must make sure that they are both charged to the same voltage.

As your bike has different motors and separate throttles, it might be better to simply connect one battery to each motor.  This way, if one battery goes flat, the other one can still be used to get you home.

Alan
 

[csm]

I'm able to use both throttles at the same time.

your using two throttles? How do you have it configured on bike? one on each grip?? or ?? Post pics/video of your throttle configuration.

I Have The Magic 2 (External Controller)

Which hub are you controlling with that? And what controller are you using to control the other hub?

I myself am trying to find out how to add another battery wired in "series" to the terminal block.
im choosing series so that the voltage stays the same instead of wiring in "parallel" which will double the voltage and fry the motors.

Perhaps you mean in "parallel"?? Bikemad posted a good pic on the effects of wiring batteries in parallel compared to series.


BTW, I noticed you have a bunch of lights on your bike. Are you wiring them into your ebike battery pack? Or are you using batteries for each light (like AA and AAA batteries or??) ??

[MagneticMotorE]

@Bikemad can you con figure for two batteries?  PLEASE?  THANKS.  IN PARALLEL. PLEASE.

[Bikemad]

This should make it nice and clear:


Alan
 

[jan-norway]

So if one connects two batteries in series to increase the voltage, then they don't have to be identical in any way?

Thanks,

Jan

[Bikemad]

Jan, although they don't have to be identical, it can cause real problems if their capacities (and sometimes their chemistries) are different.

A 36V 16Ah battery in series with a 12V 7Ah battery would give 48V, but your usable capacity would be limited by the 7Ah battery.

The smaller capacity battery would obviously become discharged much sooner than the larger one, and if there is no battery protection on the lower capacity pack, it will soon become damaged simply by allowing its voltage to fall too low, and also by the larger capacity battery trying to reverse charge it when it becomes so depleted that it can no longer supply the current being consumed by the motor.

A smaller capacity battery could be used as a temporary power boosting feature as shown here:


It would be a good idea to have some sort of audible battery warning device (or perhaps a voltmeter) connected in parallel with the relay, to automatically allow monitoring of the 12V battery, but only while it is actually being used.
If wired this way, the monitoring device would not gradually discharge the 12V battery while the boost function was not in use.

Alan
 

[csm]

Alan, I like your idea of a 12 volt booster (I am calling it a turbo mode). I was confused by some parts of your diagram, such as where to tap the battery and the relay switch and the booster switch. I drew up a modified version of your diagram to see if I could make better sense of it. Do I got it correct??

[MagneticMotorE]

I'm able to use both throttles at the same time.

your using two throttles? How do you have it configured on bike? one on each grip?? or ?? Post pics/video of your throttle configuration.

I Have The Magic 2 (External Controller)

Which hub are you controlling with that? And what controller are you using to control the other hub?

I myself am trying to find out how to add another battery wired in "series" to the terminal block.
im choosing series so that the voltage stays the same instead of wiring in "parallel" which will double the voltage and fry the motors.

Perhaps you mean in "parallel"?? Bikemad posted a good pic on the effects of wiring batteries in parallel compared to series.


BTW, I noticed you have a bunch of lights on your bike. Are you wiring them into your ebike battery pack? Or are you using batteries for each light (like AA and AAA batteries or??) ??

IM USING AA BATTERIES....

[csm]

Revision 3 of my modification for a Turbo button/switch circuit.

[Leslie]

First thing should be said..

Warning.

Make sure all batteries are fully charged and balanced before hooking them up in parallel.

.5v/.001 ohms =500 amps

A .5v potential difference between two batteries along a thick conductor could cause a lot of damage.