36 LiFePO4 cells with a 120V controller - ElMoto.net

__Tango · #1 11-13-2009

So, i have a bike (YAY! ... finally...phew.), and i have batteries on order (YAY!). I was just about to order the controller (YAY!), but got scared before i clicked on "order" (BOO!).

The proposed specs so far are: Enertrac brushless hub motor, 36 TS cells (115.2V nominal, 133.2V fully charged), a Kelly KBL controller. I was planning on using the 120V/400A version (KBL12401I) since my nominal voltage is <120V, and Mark from Enertrac recommends the 400A controller based on his experience. However, will the full charge of 133.2V be too much for the controller?

I understand that the 3.7V/cell is supposed to burn off pretty quickly to 3.2-3.3V/cell, however will i be screwed from the get-go on a full charge?

Thanks!

...tango...

remotecontact · #2 11-13-2009

Why don't you just get a 144v controller :

http://www.newkellycontroller.com/pr...38e5e655d16e6d

remotecontact · #3 11-13-2009

Still waiting on bike pics btw

frodus · #4 11-13-2009

From here: http://www.newkellycontroller.com/pr...roducts_id=213

Quote:

Operating Voltage, B+, 18V to 1.25*Nominal Voltage for controller rated equal or higher than 36V. 8V to 30V for controller rated equal 24V.

120V * 1.25 = 150V

Sounds like you're fine.

__Tango · #5 11-13-2009

Quote:

Originally Posted by frodus

From here: http://www.newkellycontroller.com/pr...roducts_id=213

120V * 1.25 = 150V

Sounds like you're fine.

Ahhh...missed that.

Controller is now ordered! Woohoo!

Thanks!

...tango...

frodus · #6 11-13-2009

and if it blows, well, its in their spec, they owe you a free upgrade

screenshot/save the page or confirm the manual reflects the same overage (1.25).

gasfreeearth · #7 11-13-2009

Quote:

Originally Posted by __Tango

Ahhh...missed that.

Controller is now ordered! Woohoo!

Thanks!

...tango...

Great Tango!

Now get to reading.

http://www.newkellycontroller.com/mo...UserManual.pdf

By the time it gets there you'll know exactly what to do.

__Tango · #8 11-14-2009

Quote:

Originally Posted by gasfreeearth

Great Tango!

Now get to reading.

http://www.newkellycontroller.com/mo...UserManual.pdf

By the time it gets there you'll know exactly what to do.

HA! I've had that PDF for weeks...and i'm sure i'll still be confused about a million things.

...tango...

__Tango · #9 11-14-2009

Just a note, before i asked the sagely advice here, i emailed kelly about it, and here's their response (just for corroboration):

Quote:

Originally Posted by Fany from Kelly Controllers

Quote:

Originally Posted by __Tango, in email

Hello,

I am planning on using 36 Thundersky LiFePO4 batteries with a brushless motor. The nominal voltage is 115.2V, however with a fully charged pack (3.7V per cell), that works out to 133V.

I understand that the cells go from 3.7V to 3.2V very quickly (a surface charge that comes off of the cells very quickly). I would like ues a 400A controller, so I would like to know if i can use the 120V controller (KBL12401I), or if i must use the 144V controller (KBL14401I)?

Obviously, i would rather use the 120V controller since the cost is $300 USD cheaper, and since the charge over 120V burns off so fast. However, i thought i'd ask you first.

No problem,the controller KBL12401I can operate with 18V-136V voltage.
So the batteries are available.

Thanks,
Fany

frodus · #10 11-14-2009

but their spec says 1.25 times the controller voltage..... so is it 136? or 150?

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