Do you think this 72v controller can handle 84v?

[LarryHoova]

Hi everyone - what are the chances that this 72v controller has 100v fets and caps?

http://www.omgeparts.com/ProductDetails.asp?ProductCode=P-CON-EAG

Do you think this controller could handle 84v system?

I really don't want to wait weeks to get a controller from china :/ even though it would be cheaper and I can buy this one now for $150 or so.

China would be $65 and 2-3 week wait

 

[999zip999]

84 volts final voltage then yes.

 

[LarryHoova]

84 volts final voltage then yes.

Well, 7 x 12v SLA's for a total of 84v - that being said, fully charged it is like 96v and drops from there.

Think this will be ok?

 

[Subsa]

nope, fully charged is 103.6V

 

[Ypedal]

Descripion - 72V 30Ah - Controller for Eagle

Spot the not .. rating a controller with battery capacity specs. = fail.

 

[wesnewell]

nope, fully charged is 103.6V

A fully charged 12V sla battery, depending on temp, is 13-14V max. Usual is ~13.5V @25C. I've never seen one above 14V, which would be 98V. I'm curious how you came up with that figure. Charge voltage for 7 batteries is series would only be 101.5V at recommended max charge voltage of 14.5V per battery. These aren't vented LA that you should equalize charge at 15.5V. And even at 14CV you will be doing nothing but burning them up faster. As soon as the charge is removed, they will drop under 14V each.

 

[wesnewell]

You want a 72V controller with 100V caps and fets, get this one at less than half the price.
http://www.ebay.com/itm/Electric-Bicycle-Brushless-Speed-Motor-Controller-72V-1500W-For-E-bike-Scooter-/360643164862

 

[dogman dan]

For the OMG price, I'd get a 12 fet from Lyens. Then have him modify it for your desired voltage.

But yeah, the one Wes points out will work fine. for a lot less. It will tolerate 90v for sure, and also for sure, you won't be above 90v for that long on the road. The small packages from china come plenty fast usually. You can't compete on Ebay and ship by boat.

 

[999zip999]

Just lose one of the dead lead Batts. Like just 6 and stop blowing things of. ???

 

[Subsa]

nope, fully charged is 103.6V

A fully charged 12V sla battery, depending on temp, is 13-14V max. Usual is ~13.5V @25C. I've never seen one above 14V, which would be 98V. I'm curious how you came up with that figure. Charge voltage for 7 batteries is series would only be 101.5V at recommended max charge voltage of 14.5V per battery. These aren't vented LA that you should equalize charge at 15.5V. And even at 14CV you will be doing nothing but burning them up faster. As soon as the charge is removed, they will drop under 14V each.

* Every chinese charger charge to 14.6-14.8V and do float to 13.6-13.8V (if have float)

 

[LarryHoova]

You want a 72V controller with 100V caps and fets, get this one at less than half the price.
http://www.ebay.com/itm/Electric-Bicycle-Brushless-Speed-Motor-Controller-72V-1500W-For-E-bike-Scooter-/360643164862

I ordered this one. I have never been over 100v - maybe my batteries are kinda crap - but 96-98 volts seems to be the max.

I am planning on doing a shunt mod once it arrives. I will probably just double the size of the shunt since I don't have a wattmeter.

 

[wesnewell]

If you get 96V out of your 7 batteries in series, there's nothing wrong with them. In fact they are in excellent shape. Anyone thinking they will be over 100V is just full of crap.

 

[wesnewell]

* Every chinese charger charge to 14.6-14.8V and do float to 13.6-13.8V (if have float)

So what. They could charge at 15V and the end result would be the battery when removed from the charger will drop below 14V. My smart charger which is probably made in China has a charge voltage of 14.5-14.6V, but that's charge voltage, but it shuts off when the battery is fully charged, and the battery will never be above 14V. And I've charged lots of 12sla batteries and resurrected a few with desulfating. An sla battery just won't hold a charge above 14V for more than seconds and smart chargers will never let them get that high to begin with

 

[Subsa]

The bridge connection of FETs, that controller have, can handle up to 2*(transistor voltage), because they are in series.
When working this is not valid, the controller can handle up to 1*(transistor voltage)
If the battery is SLA, there is possible to charge at voltage close to FET max or over it, and to work under that voltage (Typ. 12.8-13.3V/batt) 8)
So buy a charger with float function, to decrease the output voltage when fully charge.

 

[LarryHoova]

* Every chinese charger charge to 14.6-14.8V and do float to 13.6-13.8V (if have float)

So what. They could charge at 15V and the end result would be the battery when removed from the charger will drop below 14V. My smart charger which is probably made in China has a charge voltage of 14.5-14.6V, but that's charge voltage, but it shuts off when the battery is fully charged, and the battery will never be above 14V. And I've charged lots of 12sla batteries and resurrected a few with desulfating. An sla battery just won't hold a charge above 14V for more than seconds and smart chargers will never let them get that high to begin with

I noticed a quick drop off as well once I disconnect and I have never seen it says 100+ volts on the bikes built in voltmeter.

New controller has been shipped. I will take some pics after I do the shunt and install the new one. Actually I might test the bike first without the shunt just to see how much torque it has.

 

[wesnewell]

Most 72V 1500W controllers will have a max amp of 40-50A. You shouldn't need more than that. And that's going to put a big strain on your motor if you aren't careful. Don't cruise at more than 50-75% throttle. Only use max throttle for short burst of speed.

 

[LarryHoova]

Most 72V 1500W controllers will have a max amp of 40-50A. You shouldn't need more than that. And that's going to put a big strain on your motor if you aren't careful. Don't cruise at more than 50-75% throttle. Only use max throttle for short burst of speed.

Hmm I usually go full out all the time 45km/hr

How many amps will I draw if I double the shunt size?

 

[wesnewell]

45kph max is pretty dismal for 96V wot, but the heavy sla and your original controller has a lot to do with that. Before you even think about a shunt mod, you need to see what you get with it stock, which will probably be 40A. That's almost 4Kw. In a 26" wheel, you should get a no load speed of 70-80kph while drawing less than 10A. Shunt mod info here.
http://endless-sphere.com/forums/viewtopic.php?f=2&t=31643

 

[LarryHoova]

45kph max is pretty dismal for 96V wot, but the heavy sla and your original controller has a lot to do with that. Before you even think about a shunt mod, you need to see what you get with it stock, which will probably be 40A. That's almost 4Kw. In a 26" wheel, you should get a no load speed of 70-80kph while drawing less than 10A. Shunt mod info here.
http://endless-sphere.com/forums/viewtopic.php?f=2&t=31643

Interesting. My no load speed is the same as my load speed last time I checked when I was at 72v and had a max speed of 39km/h

That being said, I will see how it performs stock and go from there.

 

[wesnewell]

Interesting. My no load speed is the same as my load speed last time I checked when I was at 72v and had a max speed of 39km/h

That being said, I will see how it performs stock and go from there.

If your no load and loaded speed are the same, then you don't need more amps. The motor can't go any faster than the no load speed. Increasing amps will do nothing. Of course the controller could be limiting the speed. In that case the no load and loaded speed could be the same. I think you'll find you'll get a lot more speed with the new controller. Under load, t5he battery voltage sags in all batteries. SLA sags a lot under load and the lower the voltage the lower the speed. If you were getting the same max speed going uphill as you were on the flats, then the controller was limiting the speed.

 

[LarryHoova]

Interesting. My no load speed is the same as my load speed last time I checked when I was at 72v and had a max speed of 39km/h

That being said, I will see how it performs stock and go from there.

If your no load and loaded speed are the same, then you don't need more amps. The motor can't go any faster than the no load speed. Increasing amps will do nothing. Of course the controller could be limiting the speed. In that case the no load and loaded speed could be the same. I think you'll find you'll get a lot more speed with the new controller. Under load, t5he battery voltage sags in all batteries. SLA sags a lot under load and the lower the voltage the lower the speed. If you were getting the same max speed going uphill as you were on the flats, then the controller was limiting the speed.

Thanks for the insight. Yes I was getting the same speeds uphill or downhill so the controller was limiting the speed. How exactly does it limit the speed? Are you sure this new controller won't do the same thing?

 

[wesnewell]

I know absolutely nothing about the controller you have. It may have been programmed that way. It may have a jumper or wire inside, or something else. No, the new controller will not be limited (except for max amperage) unless you want it that way and tell them to customize it for you, or you determine how to do it and do it.

 

[LarryHoova]

I know absolutely nothing about the controller you have. It may have been programmed that way. It may have a jumper or wire inside, or something else. No, the new controller will not be limited (except for max amperage) unless you want it that way and tell them to customize it for you, or you determine how to do it and do it.

That's awesome! I am looking forward to going even faster than before! Whoooooooooooooooooooooooooooooooooooo *crash*

It was originally limited to 32km/h because that is the law here in Canada. I am not sure how they did it. There was 2 white wires coming out of the controller but they were NEVER connected together.

Either way, this new controller should show me what the bike can really do!

That brings up a question. My bike now has a 3 speed switch but the actual plastic switch broke off, so I just took the 3 wires and twisted the 2 together that permanently leaves it in the fastest speed setting.

Is there a way to just bypass this altogether with the new controller? Do I simple not connect those wires this time around.

I really hope I don't blow something installing the new controller. Good news is, from the pics, it looks virtually identical wiring as I have now.

 

[wesnewell]

Are you sure the wires you twisted together didn't limit your speed? Most 3 speed switches are just an on/off/on toggle and with all wires open the controller is in max speed setting. One of the wires will be ground and the other 2 wires are for different speed settings when connected to ground. And then there's another one that when pulled to ground it overrides the 3 speed switch and is yet a 4th speed setting. Here's general info on controllers that helped me when I first got into this.
http://endless-sphere.com/forums/viewtopic.php?f=16&t=7361

 

[LarryHoova]

Are you sure the wires you twisted together didn't limit your speed? Most 3 speed switches are just an on/off/on toggle and with all wires open the controller is in max speed setting. One of the wires will be ground and the other 2 wires are for different speed settings when connected to ground. And then there's another one that when pulled to ground it overrides the 3 speed switch and is yet a 4th speed setting. Here's general info on controllers that helped me when I first got into this.
http://endless-sphere.com/forums/viewtopic.php?f=16&t=7361

it went faster with 2 of the wires connected together. At least it did when it was at 60v.

which wires in that diagram go to this speed switch? Can I just not connect it?

What is the motor speed sensor wire for?