Question about changing from 36v to 72v

[GASSTINKS]

I have two Crystalyte Journey kits and would like to run one motor with both 36v nimh batteries in series for 72v. I realize that the existing controller can't handle that kind of voltage and I need to buy another one which can. The problem is that the Crystalyte 36-72v 20ah controller available for sale has a different sensor connection (I have a flat rectangular five-pin connector from my motor, the new controllers have the round metal XLR connector). Is swapping the connector from the original controller doable/difficult? Is there one wire corresponding to each pin that I would have to reattach? To reattach these, could I just twist both ends, then tape the exposed portions? Obviously, I'm electronically challenged and need help.

Also, is this the proper series connector that I would need to connect the two batteries?
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=4067

Thanks in advance for any pointers or recommendations. Also, if anyone has one of these controllers for sale ...

 

[Ypedal]

You could fit motor and controller with just about any suitable 5 pin male female connector.. or solder them in ( better to solder vs twist and tape )

As long as it's a crystalyte motor and controller, it's color on color.. Blue, Yellow, Green, Red , Black. same for the phase wires.

You will need to seperate the packs for charging.( plugging 2 x 36v chargers into a 72v pack = smoke if the chargers have common ground .. )

 

[GASSTINKS]

Thanks for the info, Ypedal.

Can you recommend a "Soldering 101" source on the net? I'm a neophyte with electronics, but I'm starting to learn a lot just by reading the info posted by others on this forum.

A question about power as it relates to voltage and amperage:

Say I'm able to travel 12.5 miles on a full charge using one of my 36v 10ah batteries (I think they're good for 2c, which is 20 amps ... right?). If I connect them in parallel, I'm able to go twice the distance at the same speed, since I'm extending the amperage. If I connect them in series, could I conceivably do the same distance (double the distance of one battery) going the same rate of speed I maintain when they're in parallel? So, full throttle in the parallel example, vs. half throttle in the series example: same conceivable range?

 

[The7]

If I connect them in series, could I conceivably do the same distance (double the distance of one battery) going the same rate of speed I maintain when they're in parallel? So, full throttle in the parallel example, vs. half throttle in the series example: same conceivable range?

In theory, YES.
In reality, NO. Because you would tend to have a faster acceralation when in series and this will comsume more energy even though you keep the same top speed.

 

[GASSTINKS]

Got it, thanks. It's all starting to make sense.

 

[John in CR]

...You will need to seperate the packs for charging.( plugging 2 x 36v chargers into a 72v pack = smoke if the chargers have common ground .. )

Is this right? I've got my ping packs in series and my ping chargers in series with no problems. I have to do series because the chargers won't work without the bms, but won't work at all on the pack with the damaged cell without series. The series connection works flawlessly for me charging in series through the bms on one pack and bypassing it on the other. The auto cutoff even works, and knock on wood, but the cells are maintaining perfect balance even on the damaged pack.

John

 

[Ypedal]

...You will need to seperate the packs for charging.( plugging 2 x 36v chargers into a 72v pack = smoke if the chargers have common ground .. )

Is this right? I've got my ping packs in series and my ping chargers in series with no problems. I have to do series because the chargers won't work without the bms, but won't work at all on the pack with the damaged cell without series. The series connection works flawlessly for me charging in series through the bms on one pack and bypassing it on the other. The auto cutoff even works, and knock on wood, but the cells are maintaining perfect balance even on the damaged pack.

John

Not the same animal..

The " Journey " kit using nimh however.. with the grey " Hi-Power " chargers will pop unless you snip the ground.

 

[Sacman]

If you have LED lights on your throttle you'll have to modify them too to make them light up properly at the higher voltage.

I have two Crystalyte Journey kits and would like to run one motor with both 36v nimh batteries in series for 72v....

 

[GASSTINKS]

72v won't fry the throttle, though. Will it? If I understand this stuff correctly: the throttle tells the controller how much juice to draw from the battery to give to the motor. The added bonus of the three lights on the side of the throttle is that they act similar to a volt meter. Will the 72v torch the lights?

Part of the benefit of the upgraded controller is the six-pin connector which allows the direct connection of a Cycle Analyst to monitor battery usage, etc.

 

[Sacman]

72v won't fry the throttle, though. Will it? If I understand this stuff correctly: the throttle tells the controller how much juice to draw from the battery to give to the motor. The added bonus of the three lights on the side of the throttle is that they act similar to a volt meter. Will the 72v torch the lights?

Your general understanding of the throttle is right. It's just a big variable resistor (or properly called potentiometer). The more throttle you give the less resistance you get allowing more voltage and power to flow. I know some electronics but I'm no wiz. I believe that doubling your voltage from 36v to 72v will surely fry the light circuits but I'm less sure about the throttle. You'll have to ask someone more knowledgeable around here than me.

I did previously read a thread around here where someone else was changing from 36v to 48v and similarly asked about the lights on the throttle working properly. Someone answered him that he could either buy a 48v throttle (both powerider.com and ebikes.ca sell 48v throttles) or add the few electronic components (resistors) to the 36v throttle to make it work. Sorry I didn't bookmark the thread otherwise I'd give it to you.

 

[Ypedal]

On the cheap, you can just snip the LED power wire from the throttle and use it as a non-led unit ! :wink:

The LED throttle has 4 pins, usually, green, white, yellow and/or red, ( and the LED wire is purple or blue )

Get a CA meter for proper battery status info !! :wink:

 

[Drunkskunk]

Can you recommend a "Soldering 101" source on the net? I'm a neophyte with electronics, but I'm starting to learn a lot just by reading the info posted by others on this forum.

Soldering is easy to learn, but takes practice to get it right consistently. The leads on the mini XLR are small and very close together. Its a tricky soldering job that will take a little bit of skill.
I'm not saying you won't be able to do it, but you are going to need to get in a fair amount of practice before you'll be able to.

A good opening tutorial could be found here: http://www.curiousinventor.com/guides/How_To_Solder

A good way to practice for the kind of skill the XLR will take is soldering Resistors to each other.
Get the $5 assorted pack of resistors from Radio shack, and practice by soldering the end of one to another, with no circuit board. just bare wire to bare wire.
Don't even twist them together, just point the bare ends at each other, clamp them down, and solder them together.
if you mess one up, heat up the solder, wipe it off with a wet paper tiowl, and try again

When you can get through the whole pack, you'll probably be ready to do the XLR connector.

 

[docnjoj]

I believe a Zener Diode of 12 volts to drop the 48 to 36 was mentioned for throttle! Im still using my 36 volt throttle on 42 volts and it seems to still show no lights at the end of my ride going up a big hill! That is accurate as my NiMh really drop out when pushed! All3 LEDs light at the beginning of the ride at about 46 volts! Go figure.
otherDoc

 

[GASSTINKS]

Soldering is easy to learn, but takes practice to get it right consistently. The leads on the mini XLR are small and very close together. Its a tricky soldering job that will take a little bit of skill.
I'm not saying you won't be able to do it, but you are going to need to get in a fair amount of practice before you'll be able to.

A good opening tutorial could be found here: http://www.curiousinventor.com/guides/How_To_Solder

A good way to practice for the kind of skill the XLR will take is soldering Resistors to each other.
Get the $5 assorted pack of resistors from Radio shack, and practice by soldering the end of one to another, with no circuit board. just bare wire to bare wire.
Don't even twist them together, just point the bare ends at each other, clamp them down, and solder them together.
if you mess one up, heat up the solder, wipe it off with a wet paper tiowl, and try again

When you can get through the whole pack, you'll probably be ready to do the XLR connector.

As always, thanks for the pointers. Radio Shack is on my list of stops for today's ride. Now, if I could only find one of those controllers in stock somewhere ...