Crystalyte controller at 80amps and 92v w/ lipo booster

[Lowell]

So far so good. IRFB4110 MOSFETs, extra copper in the FET solder busses, extra copper strands on the FET legs, dual Andersons (4 total) and parallel +/- wires, one extra to the shunt, and one extra straight on to the FET buss. At high speeds, the back EMF limits current down to around 40 amps, but at low to medium speeds, power is quite acceptable and gives plenty of burst passing speed. DrainBrain shows 4800-4900 peak watts input so well over 4hp is making it to the rear wheel.

The bike is really battery limited now, as my packs are only rated for 56 amps.

 

[safe]

I think it's funny how one person posts about getting MORE than 4-5 horsepower and right next to it is a guy asking how to get a boost from 200W all the way up to a mighty 350W.

There sure is a wide range of laws pertaining to electric vehicles...

 

[fechter]

The bike is really battery limited now, as my packs are only rated for 56 amps.

Isn't that the truth. Batteries suck. Geezz, do I have to make my own batteries too?

You're getting some pretty impressive results. Nice job. My 4110 controller is still sitting on the bench waiting for an X5 motor.

How much copper did you add to the buss?

How much copper did you add to the FET leads?

Based on the measurements I made earlier, the output current can be almost three times the input, so I guess that extra copper is a good idea.

I wonder if the main caps are adequate at those currents. I blew a few off them right off the board with some other controllers, so I know they take a beating (high ripple current). I was thinking about adding some of those multilayer polyester caps that are made to take high ripple current.
It's mostly a heating issue for the caps, so if the average current isn't too high, they should be OK.

How's the controller heating after a long run?

 

[Lowell]

I have 5 extra 160v, 220uf capacitors, and the controller mounts upside down with a couple of heat sinks bolted to it. No noticeable heat of any sort.

 

[fechter]

I have 5 extra 160v, 220uf capacitors, and the controller mounts upside down with a couple of heat sinks bolted to it. No noticeable heat of any sort.

Kick Butt!

How did you stuff all those caps in there?

One thought on voltage: When the high side FETs go to switch high, the voltage from the gate to source is actually about 10v higher than the battery voltage for a brief period of time. For 100v rated FETs, 90v input would put you in the danger zone. I'm not sure how much "safety factor" is built into the device ratings.

 

[knoxie]

Hi Richard

Yes I agree I have just finished installing the 150V fets for this very reason, I will get out and test it at the weekend and let you know if it is ok.

Cheers

Knoxie