Controller mods

Electric Motors and Controllers
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Harold in CR   1 MW

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Controller mods

Post by Harold in CR » Aug 26 2016 6:12pm

Anyone here care to start a conversation on modding controllers to 125V and why or why it can not be done. I'm looking for 125V at 45Ahr battery for my reverse leaning trike motorcycle build. I have to have 20Mph max for low speed hill climbing and would like 55 MPH or slightly more to avoid getting run over. I'm trying to figure a 2 speed something from a mid motor to the rear wheel.

This thing may be heavy, but, I can already see ways to cut weight on the next build, if this works well enough. Battery weighs right at 100 pounds, I weigh 223 pounds, trike weight to be determined.
Thanks to Justin, the forum is open source and NON-commercialized.

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Schlafmutze   10 W

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Re: Controller mods

Post by Schlafmutze » Aug 27 2016 10:34am

Is modding a controller to 125v doable? Totally.
Is it practical? probably not.

If you want to run a controller at 125v you're firstly going to need to change out the Mosfets to something higher than 125v rating, and even if you do that it isn't unlikely that the voltage buck converters in the controller will just blow up due to too much voltage.
All the capacitors will likely need replacing too among many other things.

Harold in CR   1 MW

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Re: Controller mods

Post by Harold in CR » Aug 27 2016 10:50am

OK. I have watched guys solder up all the traces on the PC boards, and didn't know what else it would take, other than higher voltage mosfets and capacitors.
Thanks to Justin, the forum is open source and NON-commercialized.

Punx0r   100 GW

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Re: Controller mods

Post by Punx0r » Aug 30 2016 5:51am

There's a regulator or maybe simple resistor that supplies 5V for some of the board's circuitry (Hall sensors, at least), probably other voltages as well for things like gate drive on the FETs. These would need changing to operate with a higher pack voltage.

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flangefrog   1 kW

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Re: Controller mods

Post by flangefrog » Aug 30 2016 6:45am

At that high voltage the main (15V) linear regulator would probably need to be changed to a switching regulator. A linear regulator essentially dissipates all unneeded voltage as heat. A switching regulator will be much more efficient and thus put out less heat. For a slightly lower voltage you could look at trying a TL783 linear regulator though - it's rated at 125V and is almost a drop in replacement for the LM317.

atarijedi   100 W

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Re: Controller mods

Post by atarijedi » Sep 02 2016 6:16pm

I've been thinking of doing the same thing. Picking up a Sabvoton and seeing if I can mod it to use Infineon IRFP4668 PowerFETs, upgrade the caps to 150V or 200V, upgrade any other parts inside it that need it. The only issue I can see is whether or not the firmware would let you increase the voltage, since it would be designed around the stock parts.

Although it is pricey, it might be easier to pick up a Kelly KLS8080I series sine wave controller and make it more rugged. They have both a 120V and a 144V version. I'm looking at the KLS124201-8080I, which is the 144V 200A version.

If you don't need sine wave, than Lyen's 24 FET "highway" controllers can go up to 132V, and is already designed for heavy current.

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