Over-volting a 48v/1000w Kart

[Munk]

Hello,

I'm a noob to DIY karts. I have a this little (kid-sized) go kart on the way. At some point I might like to over volt it to 60v (maybe 72v), but am unsure how extensively I would need to modify the kart. I'm hoping all it would take is a new controller, but that's why I'm asking. The problem is that I don't really have any specs on the motor or batteries other than what's in the title.

I'm not sure if anyone is familiar with this kart, and maybe knows a little bit more about it than I do? I've seen several variations of the same kart on eBay and other sites like that, but apparently this one has an upgraded brushless motor.

Thanks, and pardon any ignorance on my part

 

[itsid]

Overvolting is basically the worst idea anyone ever could come up with for more than one reason..

But hey, it's your toy

post a pic of your motor and controller (not a generic internet pic!)
if we can identify the actuall manufacturer we can tell you what it's capable of and what you could do.
(as well as should NOT do)

'sid

 

[Munk]

Oh wow, I was under the impression that over volting was "ok" so long as it was done within a certain extent. In any case, the kart won't arrive for a few days (likely 4 to 5 business days).

While we wait for photos, in general, would bumping a 48v/1000w motor to 60v/1000w cause dangerous levels of stress on the motor, or shorten the life of the motor by an appreciable degree? Or is there another way (spare swapping out the whole power system) to boost the power?

 

[itsid]

additional voltage will not necessarily create a similar increase in power..

but more than likely a drastic increase in temperature
which means loss of efficiency at best.. killing the motor at worst.
it's not mechanical but electrical stress.. you can burn your windings or overheat magnets (the more powerfull a magnet is, the less resistant it is to heat basically)

and in the end you have less or no power at all.

And sure.. some motors accept a RANGE of input voltage (in fact all do)
but if your allowed input range (tested and considered safe by the mfg) is maxed out
you should not increase the voltage to prevent it from overheating under load.

simple as that

'sid

PS no.. if you want more power, you must swap the motor and controller.

 

[dcastillo]

Heed the Sid warning

He's actually a pretty knowledgeable guy, but you will find everyone has an opinion and data to back it up. Most people will say its OK to and extent, 72V likely is beyond that ;-)

Putting 60V on it will obviously work, but you assume the risks associated with it. If the rest of the circuitry is capable, youll fry something. Best case, if designed properly youll blow a fuse, worst case start a fire. You'll obviously put more stress on the motor and shorten its life. If its lower quality you'll likely overheat it if not careful and again, fry something.
I personally over volted my golfcart motor for a bit, but constantly checked its temps and didnt run it to long or hard. Having a really good controller that can be programmed to limit inrush and max current is definitely a good thing.
-Danny

---------- Post added at 11:16 PM ---------- Previous post was at 11:16 PM ----------

argh, he beat me to the post!!!!!

 

[Munk]

Well darn. Are the majority of these issues more related to extended exposure to over volting? For example, could risk be minimized if the extra voltage was wired in such a way as to be a "boost button" you could hold down for 5-10 seconds, as opposed to having it run that hot all the time? Or is that beside the point?

 

[dcastillo]

adding a proper/safe boost button is way more complicated then you think. Another user put two motors on his cart with two separate throttles which he says worked like a boost button... So maybe add yourself a small 250W motor/controller and use that as a boost?

 

[Munk]

Sorry for the late response, you know how life goes. Anyway, got the kart and snapped some pics. I don't see any markings or numbers, must be a Chinese generic?

The only angles I couldn't get were the very bottom and the side that has the rod the drive sprocket is attached to.

---------- Post added at 08:45 PM ---------- Previous post was at 08:36 PM ----------

One thing to note about this go kart is that is has a three- setting "speed limiter" on the dash, so parents can set it to low (7mph), medium (15mph), and high (20mph). I imagine that just complicates any modifications I would otherwise do to this kart.

Speaking of which, I noticed there is space for a second 48v/1000w battery like the one that came stock. I have been considering the possibility of buying a "spare" battery, a 96v motor (if it will fit) and controller, and what that might be like to double down! This thing is actuality pretty torquey as is, though the top speed is lacking. That's probably a gear ratio thing I would need to adjust if I went that route.

 

[chancer]

Coming from a gas engine side, Your very last idea sounds good.
If it is already torquey, change the gearing to increase top speed.
??? eh I dunno?

 

[Munk]

I suppose I could also get taller rear tires too/instead. I'm not a mechanic or anything, but I have a somewhat mechanical mind and it seems that would essentially accomplish the same thing as a larger axle sprocket and/or smaller engine sprocket. In fact, if I did the 96v thing I'd probably need to do all three.