Can my controller handle 84-96v?

[LarryHoova]

I have a Daymak that came with a 60v system - using 5x12v @ 20ah

I bought a 6th battery to bring the voltage to 72v and it works fine.

Before I added the 6th battery I opened my bike to look at the controller but it says nothing - no specs on the outside.

I never opened it, I just figured what the hell, let's just try this - I heard that these controllers can probably handle 100v.

Bike works great running at 72v.

My controller looks hard to open up - they used calking or something to seal it.

I would like to add 1-2 more 12v batteries but I am not sure if the controller can handle it.

Does anyone know if these controllers CAN handle 100v?

Is there a way to test/check without opening it up?

If I HAVE to open the controller to look at it - what am I looking for? voltage rating on the capacitors? mosfets?

Since I added the 6th battery - my speed has increased from 32km/hr to 39km/hr --- IF was to get 5 more batteries and run two banks of 60v in wire them in parallel I should end up with 60v @ 40ah -- would this simply make the bike go farther - would the speed drop back down to 32km/hr? Is it voltage that determines top speed or is it simply the controller that dictates that?

If it is the controller that dictates the speed then I assume that me running an extra 12v right now through it is causing it make it go faster? Someone told me that I would go farther but not faster with more voltage, but that is not what is happening?

Also has anyone every had their front bolts/nuts rattle loose? Happened to me and my front tire almost fell off :O


thanks

 

[dogman dan]

Yes and no. Chances are it has 100v capacitors inside. But the more you increase voltage past 60v, the more you are overvolting the 5v part of the controller, which runs your throttle and hall sensors. Typically, a small resistor in the controller may or may not overheat and melt. In higher voltage controllers, 90-120v versions, a different resistor solves the problem. 90v fully charged should work ok, and if you think about it, you won't stay above 90v very long. So adding one more 12v battery should be possible. It's a risk, but you will soon be riding with less than 90v.

So you can add more volts and get more speed, but don't be amazed if that resistor cooks off and it doesn't work anymore. Even the short time above 90v could do it.

Adding more batteries at 60v, will increase range, and speed would return to same as it was with less batteries at 60v. You should see a slight increase in speed though, only 1-2 mph because the voltage on a big battery sags less under load. So while running, you will have about 3 volts more running voltage. It will seem slow now, since you are used to 72v.

One thing you will notice as you overvolt more and more, your throttle will get very touchy, since it's getting more than 5v going in, it will be hard to control at low speed. Some add resistors to the throttle, to get it back to more like normal.

 

[LarryHoova]

Yes and no. Chances are it has 100v capacitors inside. But the more you increase voltage past 60v, the more you are overvolting the 5v part of the controller, which runs your throttle and hall sensors. Typically, a small resistor in the controller may or may not overheat and melt. In higher voltage controllers, 90-120v versions, a different resistor solves the problem. 90v fully charged should work ok, and if you think about it, you won't stay above 90v very long. So adding one more 12v battery should be possible. It's a risk, but you will soon be riding with less than 90v.

So you can add more volts and get more speed, but don't be amazed if that resistor cooks off and it doesn't work anymore. Even the short time above 90v could do it.

Adding more batteries at 60v, will increase range, and speed would return to same as it was with less batteries at 60v. You should see a slight increase in speed though, only 1-2 mph because the voltage on a big battery sags less under load. So while running, you will have about 3 volts more running voltage. It will seem slow now, since you are used to 72v.

One thing you will notice as you overvolt more and more, your throttle will get very touchy, since it's getting more than 5v going in, it will be hard to control at low speed. Some add resistors to the throttle, to get it back to more like normal.

Thanks. I am going to probably buy 1 more battery and see how that goes. If I were to add 2 more I would be at 96v and fully charged would be over 100v

 

[EdwardNY]

I am going to say this I had a greentime controller that ran great at 72 volts. I figured it could handle 96 volts. I was wrong.

I only got a few miles before the controller blew and the battery was only charged to like 92 volts.

Problem was that it takes time to get another controller especially if you have to order from china.

I would personally not try it unless you have a backup controller ready as down time on the bike really sucks.

 

[dogman dan]

He's too much like me to not learn the hard way. :wink:

 

[EdwardNY]

Yeah I learned the hard way that my controller couldn't handle the higher voltage. Then what sucked was the down time when the weather was finally warming up.

After I blew my controller I then realized how important it is to have spare parts on hand. Doesn't hurt to have a $50 dollar controller on hand before testing this stuff out, because it will piss you off much more when you have to wait for another one from china or pay lots of money for one locally if you can find it.

Larryhoova, what I do not understand is how are you only getting 39KPH at 72 volts, if I am reading what you are saying correctly. At 72 volts you should be pushing 64KPH.

Honestly, I personally like keeping my voltage at 72 volts 45amps battery 100 amps phase. This is plenty fast for me and gets me to 64KPH in seconds. I would try increasing the amps before you increase the voltage above 72 volts.

Also with your front wheel loosening. I must say that every single bolt on my bike seems to loosen except for my front tire. I usually check tension on many of my bolts on my bike every single ride. I really beat my bike hard off road through grass and dirt which really rattles everything loose. It always surprised me that the front tire has always remained tight. I would think that maybe you did not tighten the bolts tight enough.

 

[LarryHoova]

Yeah I learned the hard way that my controller couldn't handle the higher voltage. Then what sucked was the down time when the weather was finally warming up.

After I blew my controller I then realized how important it is to have spare parts on hand. Doesn't hurt to have a $50 dollar controller on hand before testing this stuff out, because it will piss you off much more when you have to wait for another one from china or pay lots of money for one locally if you can find it.

Larryhoova, what I do not understand is how are you only getting 39KPH at 72 volts, if I am reading what you are saying correctly. At 72 volts you should be pushing 64KPH.

Honestly, I personally like keeping my voltage at 72 volts 45amps battery 100 amps phase. This is plenty fast for me and gets me to 64KPH in seconds. I would try increasing the amps before you increase the voltage above 72 volts.

Also with your front wheel loosening. I must say that every single bolt on my bike seems to loosen except for my front tire. I usually check tension on many of my bolts on my bike every single ride. I really beat my bike hard off road through grass and dirt which really rattles everything loose. It always surprised me that the front tire has always remained tight. I would think that maybe you did not tighten the bolts tight enough.

Thanks for the advice.

I think I get that speed because of my speed limiter built into the controller.

72v at 45amps is crazy lol

I am at 72v at 20ah right now.

I would need 6 more batteries just to get to 40ah

Perhaps I will just stick with the 72v SLA I have now at 20ah and when I can afford to buy more parts - I can get a 72v lithium pack either at 10 or 20ah and run them in parallel with my original 72v SLA's

 

[dogman dan]

Good idea not to spend too much, or get too experimental, till you understand the difference between amps and amp hours, watts and watt hours, etc.

Keep reading, it took a month or so when I began to stop being so confused.

Hunt down that speed limiter on the controller. Sometimes it's very easy, a single wire coming out of the controller, to a plug, and then back in. Unplug, and shazam!!!!

 

[dnmun]

if 6 SLA is 72V then 8 SLA is only 96V so why not try it? better than wasting money on the expensive unreliable and difficult to maintain lifepo4 packs.

it would help to have your camera on the controller when you plug it in.

 

[LarryHoova]

Good idea not to spend too much, or get too experimental, till you understand the difference between amps and amp hours, watts and watt hours, etc.

Keep reading, it took a month or so when I began to stop being so confused.

Hunt down that speed limiter on the controller. Sometimes it's very easy, a single wire coming out of the controller, to a plug, and then back in. Unplug, and shazam!!!!

Hmmm yeah I think it is time to open the controller and look at it. I am not sure how much faster I want to go lol - I don't get that much battery life at the speed I go now

 

[LarryHoova]

UPDATE: I took a look at the controller and it seems the limiter has already been detached. There is a white cord coming out of the controller that connects to itself. I connected it back together and the bike only goes 20km/hr with it on.... with it off it does 42km with the same no load.

Sooo kinda weird that it would be limited down to below 32km/hr

Also what is weird is that at 60v with the limiter off it does 32km/hr-- I think there is ANOTHER limiter somewhere limiting it to 32km/h?

DO I need to shunt mod my controller?

 

[dogman dan]

Your limiter is the load now, and your basic motor construction details. How the motor is wound determines the no load speed at a given voltage, combined with the diameter of the wheel.

So, get a new controller able to do 120v, and start experimenting with 72v on up. Till the smoke comes out of the motor. I would recommend keeping the total peak wattage well under 3000w. So a 40 amps controller might be a bad idea.

72v x 40 amps = about 3000w. Don't go beyond that. so 72v 40 amps, 100v 30 amps, and so on.

 

[LarryHoova]

Your limiter is the load now, and your basic motor construction details. How the motor is wound determines the no load speed at a given voltage, combined with the diameter of the wheel.

So, get a new controller able to do 120v, and start experimenting with 72v on up. Till the smoke comes out of the motor. I would recommend keeping the total peak wattage well under 3000w. So a 40 amps controller might be a bad idea.

72v x 40 amps = about 3000w. Don't go beyond that. so 72v 40 amps, 100v 30 amps, and so on.

Ok thanks - I get it now.

My next step is to add another 12v of 20ah and go to 84v at 20ah, then MAYBE add one more and go to 96v at 20ah.

When possible, I want to transition to 72v @ 40ah of Lithium

I will probably buy a brand new bike at that point.

Are there such things as electric motorcycles?

 

[wesnewell]

I can almost guarantee that if you go to 96V you will blow your controller. And unless you have 100V caps and fets in your controller, you will blow it going to 84V. Don't run your resting voltage lower than 10 times the number of batteries you have in series or you will kill all your SLA batteries too. If your bike has regen braking, you can expect to lose that if you keep raising voltage without adjusting LVC. And if you raise voltage and then run at wot for extended periods of time, you can expect to burn your motor up too.

 

[dogman dan]

And he'll have a blast doing it too.

Sure, there are electric motorcycles, if you have lots of money. They need even bigger batteries.