Crystalyte Brushless Controller With Regen?!?!?

[magudaman]

So I took a ride today and rode up a pretty good size hill and decided to ride back down it. I wanted to try topping out the whole system so I pedaled to assist. I was going 34MPH and I looked down at my drain brain to see what the consumption was and it was something like - 300 Watts. I quick slowed down trying to understand what was going on and then realized I was regenerating power. I regen'ed 104 mah at a max of 4.4 amps. So as anyone utilized this regen ability? Or is it bad to regen on these brushless controllers?

My set up is:

-Crystalyte Brushless 20 amp 36-72v
-409 Motor in 26" rim
-66v 4.6 ah A123

 

[Instant Karma]

If you have a rear hub motor you can use regen to generate electricity to power things like an electric fan, lamp, radio,etc. Just turn the bike upside down, plug in the appliance or dc-ac inverter to the Crystalyte controller pos/neg connection that normally connects to the batteries and hand crank the pedals and you have your own power supply. If you have a front motor you can use trainer rollers to spin the wheels but it's not as effective as spinning the rear wheel either by hand cranking the pedals or spinning on rollers.

The higher number motors like 409 411 are better for this than the lower number ones like 406. As an experiment if you hook up a 12 volt light to the controller output and ride slowly the light will go on easily but if you go past 14 or 15mph you'll probably burn it out, if you go below 5 or 6mph the light will go out. If I recall when pedaling ,the max voltage I was able to get was around 21 volts at the max speed which isn't much because of the cogging effect of the hub motor is tiring to pedal.

 

[Doctorbass]

Interesting question guys,

!! my regen number are impressive with 5305! :wink: .. I just wonder if it could push more than the 10A max charging for my a123.. ok, I have 40 a123 cells in 20s2p or 10s4p depending on my switch position, but I would need 10A or 20A of regen to reach the max recomanded charging condition....

I will test that soon!

I am presently disassembling the dewalt pack to make lighter pack, and will use 1 bms for each 10s2p. (2 total)

Doc

 

[fechter]

Regen won't hurt the controller provided the batteries can absorb all the charge. If your batteries have a BMS that limits charging current and that limit was exceeded, the voltage on the controller could rise higher than the pack voltage. Depending on how steep the hill is and how fast you can get going, you could possibly exceed the voltage rating of the controller.

If you rode up the same hill first, then the batteries will certainly absorb all the charge.

There are a number of hills around my neighborhood that are long and steep enough to cause even my disc brake to fade. In very hilly areas, regen is handy just for the braking effect. Getting juice back into the batteries is always nice too.