Controller dropping power by itself?

professor · #1 03-10-2010, 12:02 PM

I got the gas/electric going and I like it, goes around 20 mph I guess, but after a hald mile or so, it just slows down even with a steady 27v going into the batteries from the alternator. If I back off the twist grip e-thottle and jam it on full- it scoots ahead, but again,slowly slows down. Yesterday, I took readings at the motor leads and the meter shows the dwindling power being fed to the motor.
Ever hear of this before? I am about to rip that miserable black box out and go to a simpler on/off switch, but thought maybe it is the throttle? Here is a pic of the bike:

I am using the HF79 (behind the black shopping bags/ gastank above in the red bag) driving a Ford alternator (no regulator used but fed 12v off ONE batt. to the field circut) with the engine rpm set to provide 30 volts max (engine has a handy max speed setscrew),the alternator feeds directly to the battery- keeping it charged.
I had used a Delco alternator with a 24v regulator but I wrecked one reg. and had a dud to replace it, these worked OK (seemed to take a lot of engine power to run though), so wanting to get the bike going, I went to the Ford unit.
The HF seems much happier (loadwise) as it makes 30v at a very fast idle.

The engine is hidden because gas power bikes have always been illegal in NY, and even though it is electric, I want to go covert to avoid problems. It is pretty quiet but not silent- went to a bit of effort to silence intake and exhaust. Just hear the engine clatter mostly now.

deacon · #2 03-10-2010, 01:03 PM

I put the controller back on my 24v ebike and found that mine drops off power when the bike is in a strain. Ie on hills and when starting. The relay does not do that but the controller does. I think it is limiting the number of amps it draws to keep from burning up the wiring or a motor. On the flip side the relay blows the circuit breaker I installed. It did neither of those things when I ran it at 36v so I think 24v just isn't enough for the way I would like to ride. I am giving a lot of thought to going back to 36v.

Good looking bike by the way..

professor · #3 03-16-2010, 09:48 PM

Update- controller was fine, fresher batteries made the problem go away. I did switch to a Delco 10SI (the old style /metal fan) alternator with a jumped-out and discombobberated (haven't used that word in decades!) regulator.

deacon · #4 03-17-2010, 07:35 AM

The old battery drain demon. I have that happen now and then. From all the hype about the controller's virtue and it shutting down to save the battery, it doesn't seem that the drop in amps would effect output until it got to the shutdown point but mine always gets miserable performance before it shuts down. One of life's mysteries I suppose.

deacon · #5 03-17-2010, 07:37 AM

The old battery drain demon. I have that happen now and then. From all the hype about the controller's virtue and it shutting down to save the battery, it doesn't seem that the drop in amps would effect output until it got to the shutdown point but mine always gets miserable performance before it shuts down. One of life's mysteries I suppose.

I almost forgot to mention that you have one of the best looking ebikes I have seen.