Author Topic: 72V input to 48V controller  (Read 17914 times)

Offline Nick

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72V input to 48V controller
« on: September 29, 2008, 08:50:05 AM »
Hi everybody! I have 2 LiFePO4 batteries, 36V/10AH, 36V Controller ,and 500W motor. If a connect them in parallel and get 72V can I use a 48V controller?

Offline Lanchon

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Re: 72V input to 48V controller
« Reply #1 on: September 29, 2008, 09:09:06 AM »
no, you can't; you need a 72V controller, made or bought.

Offline Nick

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Re: 72V input to 48V controller
« Reply #2 on: September 29, 2008, 09:28:18 AM »
Thanks!

Offline Leslie

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Re: 72V input to 48V controller
« Reply #3 on: September 29, 2008, 09:50:07 AM »
woaaah 72 volts thats insane,

Dude!

You have a death wish. 

Bikes are not supposed to go that fast.  I can get 72 volt controllers, but unless you're building a motor bike just don't go there.

Bring it on

Offline JohnnyRocketone

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Re: 72V input to 48V controller
« Reply #4 on: September 30, 2008, 05:57:15 PM »
I just bought a 48v 1000w GM from ebay and I get 30 MPH and love it.  I'm also using a LiFePo4 48v 20AH batt.  I have been riding 22 miles a day to work and back.   Love not giving money to gas stations!     ;D
Cannondale Super Vee 2000 Full suspension with 26" x 3" tires for the ultimate comfort at speed!
« Last Edit: September 30, 2008, 06:21:01 PM by JohnnyRocketone »
Cannondale Super Vee 2000, 48v 1000w GM, LiFePo4 20AH, 3.5" Full Susp.
30 MPH, 26x3" tires.    Rides like a Caddy!   :-)

Offline Spacelander 1946

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Re: 72V input to 48V controller
« Reply #5 on: October 01, 2008, 06:56:57 AM »
I just bought a 48v 1000w GM from ebay and I get 30 MPH and love it.  I'm also using a LiFePo4 48v 20AH batt.  I have been riding 22 miles a day to work and back.   Love not giving money to gas stations!     ;D
Cannondale Super Vee 2000 Full suspension with 26" x 3" tires for the ultimate comfort at speed!
Hey nice bike JohnnyR.......I need to change my knobbly tyres,what brand are yours?....Cheers
« Last Edit: October 01, 2008, 07:00:18 AM by Spacelander 1946 »
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Offline JohnnyRocketone

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Re: 72V input to 48V controller
« Reply #6 on: October 02, 2008, 02:29:34 AM »
The 26"x3"tires are Kenda Flames.  Just to let you know, they're a tight fit!  I actually had to trim the corner of the tire slightly to get them to fit.  But the ride is plush!   Good luck!
Cannondale Super Vee 2000, 48v 1000w GM, LiFePo4 20AH, 3.5" Full Susp.
30 MPH, 26x3" tires.    Rides like a Caddy!   :-)

Offline Spacelander 1946

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Re: 72V input to 48V controller
« Reply #7 on: October 02, 2008, 10:24:30 AM »
Many thanks JohnnyR.....Hummmmm tight fit are you <?> just joking!.....AVANTI in Australia imports "Kenda Flame" rubbers. Will keep all informed when I purchase from a local Gold Coast supplyer......Cheers & good luck.
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Offline Leslie

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Re: 72V input to 48V controller
« Reply #8 on: October 02, 2008, 10:41:42 AM »
The 26"x3"tires are Kenda Flames.  Just to let you know, they're a tight fit!  I actually had to trim the corner of the tire slightly to get them to fit.  But the ride is plush!   Good luck!

Yeah very sexy bike.  Way better looking than my tank, but I like to add critique but I have to sit this one out :)

I tried the big 26x3 tyre but with 10kg of SLA's tied to the frame up near the front and another 5kg near the frame seat pole tubing and it just got all wobbles as the tyre wasnt stiff enough, so I stick to the smaller tyres 26x1.95 in the front as the bike rides wobble free this way...  Maybe if I went a steal rim at the front and used 13 gauge spokes this wobble thing would all but disapear with 26X3 tyres.

Good work dude...
 ;)

Bring it on

Offline JohnnyRocketone

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Re: 72V input to 48V controller
« Reply #9 on: October 02, 2008, 04:04:42 PM »
One thing i'd like to mention.  I don't know how you feel about the scooter trunk.  But when I lock up my bike in public places, people don't know about the battery, for the most part.  (Out of sight , out of mind.) Its got a keyed lock. (Keeps the honest people honest)    ;)
Cannondale Super Vee 2000, 48v 1000w GM, LiFePo4 20AH, 3.5" Full Susp.
30 MPH, 26x3" tires.    Rides like a Caddy!   :-)

Offline Leslie

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Re: 72V input to 48V controller
« Reply #10 on: October 02, 2008, 06:37:01 PM »
One thing i'd like to mention.  I don't know how you feel about the scooter trunk.  But when I lock up my bike in public places, people don't know about the battery, for the most part.  (Out of sight , out of mind.) Its got a keyed lock. (Keeps the honest people honest)    ;)

Yes true.  But curiosity would get the better of some one who sits around and harasses umteen people for a dollar or a smoke and such.  This is where it goes wrong.  I don't think it would matter what you had in there.  You could have lots of money.

I could go into to detail about how my bike was screwed over but it is only speculation and could be racisit but lets say we sort of know who it is and why.

My wife put a big lock on our bike and just ended up damaged..

Bring it on

Offline biohazardman

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Re: 72V input to 48V controller
« Reply #11 on: October 03, 2008, 03:20:04 AM »
woaaah 72 volts thats insane,

Dude!

You have a death wish. 

Bikes are not supposed to go that fast.  I can get 72 volt controllers, but unless you're building a motor bike just don't go there.

BUt BUT BUT I gots a 72v controller and 72v worth of Lifepo4s should I not destroy this bike before I start on the next?  ;^)  It's just a thought right now as it has 4 broken spokes and a flat tire.  It's not going anywhere untill the spokes come then it gets a new properly drilled rim, new tire, spokes and tube. By then my other bike might be ready to ride. Waiting for a rim and rear rack and have to figure out how to mount 24lbs worth of batts down low and in the rear as wel as get a road crank on the mountian bike. What an addiction this is turning into. :o

Offline Nicobie

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Re: 72V input to 48V controller
« Reply #12 on: October 04, 2008, 02:29:37 AM »
I hear U bioM,

My $100 walmart bike will most likely end up costing $450. And that is with out the motor, wiring, and lifepo4 batteries. And not counting all the sla's I probably will be tossing. I hate to say it, but I spent about an hour today on bikesdirect.com.  Hahahahhaaaa...

It is fun though.   ;D ;D ;D ;D ;D

Nick

Offline Spacelander 1946

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Re: 72V input to 48V controller
« Reply #13 on: October 04, 2008, 04:51:43 AM »
You need a full suspension bike Bio man!....try ebay? I purchased my Chinese GHAO bike for $290AUD, I did have to replace the crappy wire disc brakes with quality Avid "juicy" hydraulics now I can stop! can take lots of weight (with adjustable suspension) and is smooth to boot!..... Cheers & good luck

« Last Edit: October 04, 2008, 04:59:51 AM by Spacelander 1946 »
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Offline biohazardman

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Re: 72V input to 48V controller
« Reply #14 on: October 04, 2008, 06:34:40 AM »
You need a full suspension bike Bio man!....try ebay? I purchased my Chinese GHAO bike for $290AUD, I did have to replace the crappy wire disc brakes with quality Avid "juicy" hydraulics now I can stop! can take lots of weight (with adjustable suspension) and is smooth to boot!..... Cheers & good luck


You are right about the full suspension bike and I really like the looks of yours nice job. The Schwinn was my first try and I got it off of craigslist.  A 1991 bike in like new condition and at 30lbs it was great.  But after putting 1200 miles on it and another permanent disability to add to the others on my bod I found myself in need of the full suspension you suggest.
I tried craigslist for several months and every time I found a high end bike for <$500 someone got there before me. So the addiction got together with the voices in my head and made me buy a new one for twice that ouch.  I have most of the parts now and am figuring out how to mount 72v worth of batts, deciding on which rack to modify, looking for spokes for the front wheel and trying to get the rear disk adapter from  texaselectricbikes as they said they had one for me.  I have high hopes of having it running in the next two or three weeks.  Good thing it will be raining for the next six months or so as that will keep me from having to much fun?  ;^) I usually spend less on the cars I drive than I have spent on this bike.

list of mods as follows

BMC rear motor with mods
72v Foxpower lifepo4
Modded Topeak rear rack for the batteries
72v 45a controller
Remote throttle the front gear thumb shifter will control it
Front and rear disk brakes with 8" rotors
Reed switch for brake cutout of the motor
Road crank with 50 or 52 teeth if I can clear the frame
Custom built carbon fiber 3 Cree LED headlight
Carbon fiber handlebars just cuz they were cheap
Fender mounts and brackets will be Delrin and carbon fiber when I get it figured out.
Lets not ferget the custom lightweight trailer I'm building to carry these batteries for some serious range after I upgrade to some a bit lighter.

It should be fun with 50+ mile range when I get everything together. But 20 mile range for now.





« Last Edit: October 04, 2008, 07:41:36 AM by biohazardman »