How to upgrade 48V 1000w kids buggy?

[JBakes]

Hi,
I recently bought an off road buggy with 1000w brushless 48v buggy https://www.stormbuggies.com/products/red-mud-monster-1000w-20ah-48v-kids-electric-go-kart

It's only doing about 15mph so I'm wondering what could be done to make it faster? Could I upgrade the motor?

I'm a newby to electric

 

[e-beach]

If you are a newbie, then I recommend that you do lots of research before you start making changes. The first this to consider is if your buggy can take more speed structurally.

The most basic formula kind-of goes like this:
Volts = speed (rpm's)
Amps = torque

It is really not that simple but it will give you a start on the concept of volts and amps.

So, yes you could increase your voltage and that would increase the rpm's of your motor provided you don't over heat the motor and burn it out, or, over-volt your controller and burn it out.

Do you know the specs on your controller? The specs of your motor? Specs on you battery?

It might also be done with gearing, but you would loose low end torque if you change your gearing to go faster with your current motor/controller/battery setup.

You might also get a modest increase in performance with a different battery chemistry depending on what kind you are running. Like running RC Lipo vs LiFePO4

Or, by increasing the wire size of your phase and power wires depending on how big they are in comparison to the size of your motor winding. Bigger gauge wires can have less resistance, but if your wiring harness' and windings are already are already about equal in gauge, you will not get much improvement, if any.

So, your assignment, if you chose to take it is to learn as much about the specs of your buggy setup and it's components while reading everything you can about how motors / controllers / battery's work together.

 

[markz]

Find where the motor is, find where the controller is and see if you can change out the motor so something like say this
https://goldenmotor.bike/product/48-volt-5kw-bldc-motor-air-cooled/
or
https://goldenmotor.bike/product/72-volt-3kw-bldc-motor-air-cooled/
or Unite motors - 48 Volt 1600 Watt Brushless Electric Scooter Motor
or 60 Volt 2000 Watt Brushless Electric Scooter Motor
https://www.electricscooterparts.com/motors-my1020.html

 

[amberwolf]

It's only doing about 15mph so I'm wondering what could be done to make it faster?

The site says "Two speed settings - Approximately 10mph & 20mph", so if it's not able to do 20mph on flat ground with no wind, you should first talk to the seller about that.

If you aren't using it on flat ground with no wind, it may require hardware changes to go faster.

But, some things to consider first:

Are it's brakes capable of stopping it properly at a faster speed?

What happens if you turn sharply at faster speeds? If it's already squirrely at its' max speed, then it could be dangerous at higher speeds--it could just flip and roll.

If it's used on rough terrain, faster speeds may make it unrideable unless it has really good suspension (or you're willing to upgrade that).


If you don't care about any of that and have good medical insurance, then if this thing uses a hubmotor, the simplest way to make something go faster is to increase the voltage, by replacing the existing battery with a higher voltage one that is also capable of higher current (cuz you'll need that, too). Speed is roughly proportional to voltage, as long as there is enough power from the battery and controller to reach and maintain that speed vs air resistance and terrain. So if you have a 48v battery now, going to say, 60v would be 60v / 48v * 15mph = about 18mph. 72v / 48v * 15mph = 22mph. Etc. But you may have to change the controller (and anything else that runs on the battery) to one that can handle the new higher voltage, and the higher current it will take to maintain the higher speed (which goes up faster than the voltage/speed does).

Alternately, if it is not a hubmotor, but instead a chaindrive from motor to wheel, you can change the sprocket size on either motor (larger) or wheel (smaller) to make it faster, though again you may have to change the battery and controller to support the higher power level needed for the higher speeds.

In both cases you may also have to change the motor if it gets too hot under those conditions, or find a way to cool it better.


If you go to https://ebikes.ca/tools/simulator.html and read teh entire page so you know what eerything is and how it works, then play with different systems under different conditions, you can learn more about how everything interacts to change from a slower system to a faster one.

 

[JBakes]

The motor is a UNITE permanent magnet brushless :
Max output 1000w
rate current 13.5A
rated speed 900 RPM???

The batteries I know are 20ah 48V and are lead acid I believe. Not sure on the controller yet

It's running in a grass field. The 15MPH was on a slight downhill, but there would be drag from the wet muddy grass. Even so you would think the downhill would have compensated for it.

 

[LeftieBiker]

Just replacing the SLA (lead acid) batteries with a similar lithium pack will improve performance, by reducing voltage sag - assuming it's a good quality pack. You could try going with a somewhat higher capacity lithium pack alone, and if that doesn't produce enough speed, then go one of the routes suggested above. If you want to take two steps at once, then the better pack, plus slightly higher gearing, may do it.

 

[JBakes]

Just replacing the SLA (lead acid) batteries with a similar lithium pack will improve performance, by reducing voltage sag - assuming it's a good quality pack. You could try going with a somewhat higher capacity lithium pack alone, and if that doesn't produce enough speed, then go one of the routes suggested above. If you want to take two steps at once, then the better pack, plus slightly higher gearing, may do it.

Should I stick to 20ah or is there advantage to increasing to 30ah or more? Any battery recommendations?

 

[LeftieBiker]

30AH would be a good improvement. Between that and being able to safely use 80% of the capacity instead of 50% with SLA, you'd notice the difference. I don't know manufacturers well, but I will say, that if you want a SAFER lithium pack, with much less danger of fire, then I'd suggest a Ping LiFePo4 chemistry pack. Less energy density than LiPo, but safe and if cared for, long-lived. I have a good 20AH Ping pack from 2014 that still works fine. I think the site is at pingbattery.com.

 

[e-beach]

I run LiFePO4 for safty, but they have more sag then the SLA's I originally ran.

 

[LeftieBiker]

I run LiFePO4 for safty, but they have more sag then the SLA's I originally ran.

When I switched my EZIP Trailz from SLA to that Ping 20AH pack, it was as if I'd also boosted the motor's power by 25%. It only sags noticeably when it gets below about 35% charge. Another advantage is that if the buggy has a typical three LED battery gauge, the LiFePo4 packs work better with them than the OEM batteries - you really can tell by the display when the battery is getting low and when you need to stop and recharge.