what do i need ? a better controller ?

J

jimmyjohn

1 mW
Joined
Feb 4, 2019
Messages
11
I have a 1500watt hub motor and I now have a 48V-11.6 dolphin battery on my bike. I thought I would get more speed than I'm getting now, could a upgraded controller help with more speed ? right now mine reads:
DC MOTO CONTROLLER BY LITHIUM BATTERY
VOLTAGE:DC48V BRAKES LOW LEVEL CURRENT 18A BOOSTER 1:3
Sl_ET SET1. 1-4.2VDUAL

ANY SUGGESTIONS ? what about the one that Luna sells ? to much power ?
 
Welcome. I'd suggest searching the forum for terms like "go faster" or "increase speed" and you should find the info you are looking for.
 
You're probably sitting pretty close to the amount of power you can pull from that battery without seriously affecting it's lifespan. You might get away with a 25A controller, but that's about as far as I'd recommend stretching it.
 
Your battery is the limiting factor, not your controller.
With that little 11.6Ah battery you can't draw 35A without a heavy voltage sag. That's the reason why you're getting slow speed. Get a better battery with either better cells or better capacity, both would be the best.
 
Thank you for the quick responses! So if it’s the battery ? Should I get a 56v or what would you recommend for the down tube ?
 
jimmyjohn said:
I have a 1500watt hub motor and I now have a 48V-11.6 dolphin battery on my bike. I thought I would get more speed than I'm getting now, could a upgraded controller help with more speed ? right now mine reads:
DC MOTO CONTROLLER BY LITHIUM BATTERY
VOLTAGE:DC48V BRAKES LOW LEVEL CURRENT 18A BOOSTER 1:3
Sl_ET SET1. 1-4.2VDUAL

ANY SUGGESTIONS ? what about the one that Luna sells ? to much power ?
Click to expand...
Do you have a voltmeter?

measures the charged battery, maybe it exceeds 48v already.

maybe you have a hub with a few rpm,

which is why you're slow.

you need to know how many rpm your hub has.
 
My best guess is your battery is getting killed by your controller already. A slow death, but its squealing like a pig I bet.

Get a real voltmeter display of some kind. If your battery voltage sags 8 volts or more when you take off from the stop sign, your motor and controller are killing the battery. 6 volts drop under load would be about normal. A happy battery would see about 2-4v sag. If you have even 6 volts drop when cruising at top speed, then you are running at 6 volts less than your potential top speed.


For your setup to see 2v sag, you'd have to use a LOT less throttle, and pedal like mad.

No idea what speed you expected, but 25 mph is typical, once you have run the battery a bit.

And, nobody likes to bring this up, but your weight can be all the problem, if you are over 200 pounds.


if your controller is 48v 18 amps, then your controller is 864 watts, not 1500w. 25 mph takes at least 800w.


Sometimes, a European sold setup is speed limited, by the controller.
 
Thank you for all your help. So it looks like I should start with a better controller, than the one I have ( picture below)
Then after that, might need to upgrade to a bigger battery, maybe 52V 20Ah ?
In you opinion.....which one would you recommend ?
 
A "better" controller will probably not give you more speed, and might damage your battery. It is important to match the controller current draw to not exceed what your battery can deliver. Without knowing the specs on your battery, motor and controller it is hard to identify what is bottlenecking your speed.
 
jimmyjohn said:
Thank you for all your help. So it looks like I should start with a better controller, than the one I have ( picture below)
Then after that, might need to upgrade to a bigger battery, maybe 52V 20Ah ?
In you opinion.....which one would you recommend ?
Click to expand...

Sounds like you're set on getting a controller; I think you really can't go wrong with this combo, provided that you're upgrading your battery anyway afterwards. Or you can program it not to draw too much from your existing battery.
https://www.ebikes.ca/shop/electric-bicycle-parts/controllers/phaserunner-bk.html
https://www.ebikes.ca/shop/electric-bicycle-parts/cycle-analysts/ca3-dps.html
 
Buy a controller if it makes you happy, but I still think your battery is squealing like a pig.

Find out how much sag you have before you buy a controller. You can parallel another same voltage battery to stiffen it up, if sag is your problem now.

If you are buying more battery first, then you buy that, then the controller.


How much speed do you want? if you want 40 mph, then you need to go to 72v controllers, and batteries.
 
I agree with dogman dan, it does sound like you are stressing the battery too much. Voltage drop will decrease your top speed. If you would like more info on batteries, here is a good guide: https://www.ebikes.ca/learn/batteries.html
 
jimmyjohn said:
Thank you
Click to expand...

Well that was a delayed response! Did you end up figuring out your issue? I have the opposite problem. Very happy with power but battery dies really quick. I'm still waiting on my voltmeter but I figure it's a combo of weight of rider and hills. For the record my controller of 15 amps 30 amps max has what I would consider a good amount of power even though I neutered it to max at 1000 watts.
 
I ended up buying a 1500 W fat bike kit with a 48 V 30 amp controller, it seems if I cruise for more than 2 miles, the controller stops working. I use a 52V battery, but I figure it should still work? Should I just get a sine wave controller 42 - 72 Volt will this solve the problem ?
 
Your battery is probably hitting it's low voltage cutoff, which can happen even if it's not "empty", if you're drawing far more current than it's rated to provide.

A battery being overdrawn will lower it's voltage output as it struggles to output enough amperage, low enough and the controller will interpret it as being dead and turn off to avoid damage to the battery.

If it's hitting LVC on a 48V controller with a 52V battery, it's actually a little more dead than normal dead.

You need a bigger battery, you're pulling 30A from a battery made for about half of that.
 
dustNbone said:
You need a bigger battery, you're pulling 30A from a battery made for about half of that.
Click to expand...

It's unclear what battery the OP has currently since he started with a 48 V battery and his last post is where he first indicated he's now using a 52v battery instead of the 48v dolphin pack. If it's 52v 20 Ah like he planned on a few posts up, then they'd need to be pretty crappy cells to die after 2 miles.
 
Hello, and thank you for the responses ! It has been awhile, so here's the update, sorry for the confusion, you're ALL such a great help! I bought a 48V 1500W Brushless DC Motor/180℃ copper winding with best magnet,35A Smart controller（12 MOZ tubes in it, Germany quality）, 26" 1500W Fat E-bike Double-wall RED alloy rims spoke,with match LCD Display together to support Regenerative Function ( I don't know if I can tell you the name of the company I got it from ) I had a 48V 11.6Ah battery, it died.
Since that time I have bought a 52V 14Ah battery, the problem I keep having is.....sometimes when I give it throttle from a stop it hesitates, then it might even cut-off, or jump/jitter a moment. I don't know what is going on ? I have fried two controllers from the company I bought the kits from, I have decided to buy a 45A 48V 1500W/2000W DC Sine wave Brushless, 18 Mosfet Controller, maybe this will fix the problem I keep having, as to why I keep toasting my controllers ?
thank you for your help and understanding.
 
A larger controller is not going to solve your problem. Did you buy the kit and battery together from the same supplier? If not, then the battery may not be upto supplying 35 amps for an extended period. Either the cells or the BMS in the battery could be the causing the cut out. Most 52v batteries I have seen are built for use with the Bafang BBS motors, which only draw 30 amps max.
 
jimmyjohn said:
Since that time I have bought a 52V 14Ah battery, the problem I keep having is.....sometimes when I give it throttle from a stop it hesitates, then it might even cut-off, or jump/jitter a moment. I don't know what is going on ? I have fried two controllers from the company I bought the kits from, I have decided to buy a 45A 48V 1500W/2000W DC Sine wave Brushless, 18 Mosfet Controller, maybe this will fix the problem I keep having, as to why I keep toasting my controllers ?
thank you for your help and understanding.
Click to expand...

Can you provide a little more information about the battery you bought, the type of cells it uses, if there is a BMS and the rating? Also, do you have a display or way of monitoring the voltage or power when you hit the throttle?

I don't have the extra rotating mass of fat tires, or use full throttle from a standing stop, but if I do, I see my LCD peg at 2000 watts, which is the max it can display. I did some testing yesterday to check the voltage sag on my battery under different conditions, and from a 58v charge, with the full throttle at stop I saw the voltage sag briefly to just under 53v (surprised me), so I'm guessing it's pulling more than 40 amps from the battery at that point (52v 20 Ah pack with cheap Chinese cells). As the voltage sags, more current has to flow to achieve those watts.

The higher capacity controller may help with toasting your controllers, but may not get rid of the of the problem, if the battery is the root cause of the failures.
 
Here's the only info I could find on the battery............Battery Datasheet
Model Dolphin
Nominal Voltage 52V
Nominal Capacity 14Ah
Weight Approx.3-4kg
Battery color black color or white color(Default black color)
Sutiable motor 200W/250W/350W/500W/750W/800W/1000W/1200W
Battery Dimension 81*131*360mm
Standard Charge 2A
Fast Charge 3A/4A
Standard Discharge 20A/25A/30A
BMS 45A Peak
BMS function Over-Current Protection,Over-Discharge Protection, Over-Charge Protection,Short-Circuit Protection, Balance
Charger 2A/2.5A charger

I do have the LCD 3 display , it can tell me the volts, when I hit the throttle. But I didn't look down at it, when it died. So I have no way of knowing what the reading was.

So in order to do better, should I order ..what type of battery ?
....what type of Controller ?
does a Sine wave controller eliminate all these problems ?

Can I say where I bought the kit ? and battery ?
What are your suggestions for the best company to buy high power kits from ?
 
jimmyjohn said:
I do have the LCD 3 display , it can tell me the volts, when I hit the throttle. But I didn't look down at it, when it died. So I have no way of knowing what the reading was.
Click to expand...

I would start by providing the data, otherwise nobody can help you. Go for a ride and note the voltage when you hit full throttle from a full stop. Then do the same thing, noting the watts. Report back.

If you have a link to where you ordered the battery, that may help. For that pack to provide to the specs, it has to have some decent (3C) cells, so knowing that it came from a reputable source is important.
 
But I didn't look down at it, when it died. So I have no way of knowing what the reading was.
 
Just link to the data sheets for each component, and ideally the purchase link as well if different.

Otherwise it's all just a guessing game
 
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