72v Maybe Be To Much for XB-600

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hguido1
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72v Maybe Be To Much for XB-600

Well, Bike is still running fine but can't get over 26mph on full charge. It has been colder here lately and my battery pack is fully charged at around 80 volts. Seems like it was higher before. I have charged a few times with the same result. Not sure why it won't go any faster. I checked my connections today and all seems to be the same. So my thoughts now turn to the motor, new controller or the batteries wearing out. The batteries are brand new less than a month old and the controller is two weeks old. The motor is only two months old so I am at a loss unless 72v into this motor is basically wearing it out. If anyone has been running their stock motor at 72v for a while now please let me know how that is going. Thanks

hguido1
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Re: 72v Maybe Be To Much for XB-600

By the way I have to remove my 6th battery for charging and when I rehook it up there is always a little spark. Could that be damaging anything like mosfets in the controller or caps. Also could a mosfet or a hall sensor go bad and the bike still run fine just a little slower?

sixpax2k9
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Re: 72v Maybe Be To Much for XB-600

That spark is normal. I doubt a sensor is bad, I saw u mention it is colder there.... yes, that causes the batteries to not charge as high as in warmer weather and thus would slightly decrease speed.

Dave ; Tennessee
XB-600.

hguido1
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Re: 72v Maybe Be To Much for XB-600

Ok, I was hoping that someone would say that. Thank you sixpax2k9. I also read your answer on the gray wire connection in the other thread. Thanks for that as well.

I inflated my front and rear tire to 45 psi so maybe that will help. The front was 30 psi and the rear was at 42psi.

The weather will get warmer here soon so I will try testing again.

hguido1
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Re: 72v Maybe Be To Much for XB-600

Was able to see 27mph today with inflated tires to 45psi. Will charge pack fresh tomorrow and see if 28 or 29mph is back.

JamesS
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Re: 72v Maybe Be To Much for XB-600

I get 29 to a max of 31.2 measured with a gps from my XB 600 at 60 volts. I weigh 165 lbs and on the flat 28-30 is the norm. Even when my pack was dying it would start out at that for max speed. it just didn't last long. Now i won't BS you, 31.2 is just out the gate, but 29 is good for about 5 to 8 miles depending on stops and grades. My tire pressure is at 36psi.
I am sorry to say, but I don't think you got squat out of you new controller other than an head ache over the stock controller with a shunt mod. 72 volts at 45 amps is 3240 watts. You are never going to see this and even if you could your batteries would give out in short order. That is 5.4 times the motors rating. and it would burn out too.

Happy scooting,
JamesS

hguido1
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Re: 72v Maybe Be To Much for XB-600

I get 29 to a max of 31.2 measured with a gps from my XB 600 at 60 volts. I weigh 165 lbs and on the flat 28-30 is the norm. Even when my pack was dying it would start out at that for max speed. it just didn't last long. Now i won't BS you, 31.2 is just out the gate, but 29 is good for about 5 to 8 miles depending on stops and grades. My tire pressure is at 36psi.
I am sorry to say, but I don't think you got squat out of you new controller other than an head ache over the stock controller with a shunt mod. 72 volts at 45 amps is 3240 watts. You are never going to see this and even if you could your batteries would give out in short order. That is 5.4 times the motors rating. and it would burn out too.

I was able to get 24mph with 60v shunt mod. My understanding is voltage determines top speed so for you to be able to get 29mph out of 60v is incrediable. How did you do it? No one on this forum is seeing speeds like that with just 60v. Did you rewire the bike? The current I am able to get would show up in the low end of the bike (Torque) which it is very fast getting to the top speed. Much faster than the 60v shunt controller but it is limited by the small wires to the motor. This controller is rated at 1500w which is usually a rms rating. It has the capacity for 45 amps if the load requires it.

JamesS
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Re: 72v Maybe Be To Much for XB-600

I haven't rewired anything other than adding the fifth battery which I did without changing the original wiring. All the addition plugs in between the battery pack and controller and can be switched in or out depending on how I want to run, 48 or 60 volts.
As far as this being incredible and no one else seeing these speeds I would direct you to http://visforvoltage.org/forum/3534-30-mph-xtreme-xb-600-60v-modification-instructions.
And saying that your new controller is faster getting to max speed than a shunt modded controller, would require knowing what the max current the modification allowed. Different wire size or length of the added wire of the shunt mod would have to be considered.
So I stand behind my original statement, changing the controller without changing the motor or going over the controller voltage limit, you would gain nothing. Ok maybe some speed increase now because you wallet is lighter.
I find that maximum efficiency at 60v is about 17MPH. I don't mind riding at or close to this speed. Traffic sometimes requires you to ride at full throttle, I try to avoid that. I want my batteries to last as long as possible, so jackrabbit starts and full speed runs are only shortening my battery life and distance.
How much range have you lost due to the faster acceleration, if you know? No free lunch!
Did you ever mod your stock controller? Modding the current does not effect top
speed. I missed your posts if you did.

Happy scooting,
JamesS

sixpax2k9
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Re: 72v Maybe Be To Much for XB-600

Zerogas was using the stock speedo for those speed reports... I dont have any really flat surfaces here to do proper testing, but with my moded stock controller and 60V there is absolutely no way I could get the bike up to 29/30 mph unless I was going down a big hill. While I agree that any increase he got out of the new controller was at a higher cost than need be, that was his choice. Also, I think he was planning on changing out the motor at some point as well. Yes he did run the bike at 60V with a shunt modded controller first. I know the shunt mod decreases distance because of the larger drain on the batteries. Perhaps I need to get out my GPS and/or re-measure my tire diameter since I have put on new tires since I programed my cycle computer.

I will break out the old GPS soon and re-test to see if my 24mph is accurate or not..

Dave ; Tennessee
XB-600.

hguido1
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Re: 72v Maybe Be To Much for XB-600

I haven't rewired anything other than adding the fifth battery which I did without changing the original wiring. All the addition plugs in between the battery pack and controller and can be switched in or out depending on how I want to run, 48 or 60 volts.
As far as this being incredible and no one else seeing these speeds I would direct you to http://visforvoltage.org/forum/3534-30-mph-xtreme-xb-600-60v-modification-instructions.
And saying that your new controller is faster getting to max speed than a shunt modded controller, would require knowing what the max current the modification allowed. Different wire size or length of the added wire of the shunt mod would have to be considered.
So I stand behind my original statement, changing the controller without changing the motor or going over the controller voltage limit, you would gain nothing. Ok maybe some speed increase now because you wallet is lighter.
I find that maximum efficiency at 60v is about 17MPH. I don't mind riding at or close to this speed. Traffic sometimes requires you to ride at full throttle, I try to avoid that. I want my batteries to last as long as possible, so jackrabbit starts and full speed runs are only shortening my battery life and distance.
How much range have you lost due to the faster acceleration, if you know? No free lunch!
Did you ever mod your stock controller? Modding the current does not effect top
speed. I missed your posts if you did.

Where do I start to answer. Yes I did the shunt mod at 60v and like other people on here I got an accurate speed of 24mph on a bike computer and gps from my iphone using a speed app I bought for my phone. I can honestly tell you that the lowend torque seems to be better than the 60v shunt mod. I do receive speeds of 29mph again on my bike and with a little down hill I have seen 31mph. It has been really windy here lately . I believe that is why my bike was running slower around 26-27mph top speed. I have never dranined the batteries all the way down to figure max distance at 72v. I have rode 18 mph using pretty much full throttle on one charge. I then tested the batteries and determined that they had 12.5 volts on each. So they where about 50 to 60% drained. The bike had slowed down to around 23mph top speed at that point. I am sure I could get 20-25 miles on a full charge and still be doing the original 20mph top speed of the bike. I will add another motor soon and I now have a controller that will allow me to do so. I plan to move to 84v and a 1500w hub motor.

I am sure the bike's current wiring isn't allowing me to get the full potential of this controller but that is easly fixed when I get a new hub motor. Besides my understanding is top speed is from increased voltage to the motor not current. The thread you refer to is based on the highly inaccurate stock speedometer. In other threads most have said that it is 4-5mph off. So zerogas speed on the video of 34 or 35mph is really 29-30mph on an accurate speedometer. I would like to refer you to this site http://www.bergerweb.net/xb500/v72.shtml
It clearly show the resistance of the shunt mod that was done and the speed of 24mph it also shows 72v speed after the stock controller has been changed with higher caps and mosfets. Are you sure that you setup your bike speedometer with the proper tire size? That could make a difference in your speed readings. If the speed you are receiving is accurate then can you please post exactly what you used for your shunt mod wire and size? I'm sure several other here that are planning to mod or have modded the controller would enjoy getting some additional speed with a better way to do the 60v shunt mod.

JamesS
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Re: 72v Maybe Be To Much for XB-600

If the speed you are receiving is accurate then can you please post exactly what you used for your shunt mod wire and size? I'm sure several other here that are planning to mod or have modded the controller would enjoy getting some additional speed with a better way to do the 60v shunt mod.

Since the shut mod would have no effect on top speed, it really doesn't matter.
My bike computer is calibrated correctly and has been verified with a GPS and radar displays in the school zones I ride through every day.
Since you didn't bother to fill out a complete user profile I have no way of knowing your location. Here is Deming, NM. at just over 4300 feet above sea level my drag is .16 less than at sea level. perhaps that is why my speed seems out of normal. I don't know why I get the speed I am getting, but I assure you it is accurate.

Happy scooting,
JamesS

hguido1
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Re: 72v Maybe Be To Much for XB-600
If the speed you are receiving is accurate then can you please post exactly what you used for your shunt mod wire and size? I'm sure several other here that are planning to mod or have modded the controller would enjoy getting some additional speed with a better way to do the 60v shunt mod.

Since the shut mod would have no effect on top speed, it really doesn't matter.
My bike computer is calibrated correctly and has been verified with a GPS and radar displays in the school zones I ride through every day.
Since you didn't bother to fill out a complete user profile I have no way of knowing your location. Here is Deming, NM. at just over 4300 feet above sea level my drag is .16 less than at sea level. perhaps that is why my speed seems out of normal. I don't know why I get the speed I am getting, but I assure you it is accurate.

I am sure that you are explaining your speed correctly. I think it is great that you are able to acheive 29mph on 60v. I wish there was something that could be addressed that would help other user's to obtain that speed at 60v.

JamesS
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Re: 72v Maybe Be To Much for XB-600

I am sure that you are explaining your speed correctly. I think it is great that you are able to acheive 29mph on 60v. I wish there was something that could be addressed that would help other user's to obtain that speed at 60v.

I wish I could tell you what makes the difference. I have documented any mods I have made in other posts. I am leaning towards my high altitude and high temperature. Both reduce drag. 24 mph X 1.16= 27.84. when using a air density calculator online my drag was 1.19. I can't tell you that this is why, as I am also interested as to the disparity in reported speeds. I did go out yesterday and had 29.8 on my GPS and bike computer. my next upgrade is an amp meter and volt meter so I can calculate power.

Happy scooting,
JamesS

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