Over voltage on Speed controller?

Hi,

Today I found out that my electric scooter has a 36 volt motor and it has a 24 volt speed controller. I'm sure it is 24 volts can I over-volt it to 36 volt with out causing harm it has been OK for a while now but I'm thinking of the poor capacitors there only rated at 25v and that why I dont think it will matter as normally there rated a lot higher than that for a safety margin also sealed lead acid battery's have a nominal voltage of 24v and there charged voltage anything up to 30 volts,

I,m just hoping that the MOS-FET's that drive the PWM (pulse width modulation circuit) are rated over 36 volts

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lemonie6 years ago

If you want 36V you'll need to add another 12V battery. It's quite a step-up though, your controller may not handle it well.

L
iceng6 years ago
It almost types like you are asking for permission for something you  have already tried,   Soooo..... YES  go for it !!

If I made a controller I certainly would have put 50 V Fets into the ckt.
But worry about the cooling which is Volume mass related and
a function of peak supply voltage and most likely to be marginal
because it's always reduced by manufacturing, sales and
sometime the CEO.
The worst Fet heat condition is HALF power or speed or voltage to your
motor.

I don't care about hyperbalie on PWM...  Increase system voltage expect
increased slow and stall current and more fault heating coil destroying
current if a Fet dies to a short condition in return for more speed and
oomph.

And i have not even begun on overhauling speed conditions.

A

Not only will the voltage increase, so will the current, by a LONG way, that's more likely to kill your mosfets than the volts.

BEWARE.

Steve
Daniel Deacon (author)  steveastrouk6 years ago
No the current goes down with voltage as this happens with all induction motors it uses 9.6 amps 36v and just over 15 24v
Oh yes, I'd forgotten these things are brushless.

Steve