OK to run my OEM 24V EVG at 36V?

Any real problem with this?

maybe.

you have see what the voltage ratings of the capacitors and mosfets are first. and figure out how to do the voltage drop from 45V of the 36V pack down to the 24V of the SLA.

Thanks for comments.

Will the Heinzmann probably be OK at 36+volts? Having a hard time determining upper limits of this motor.

yep, the 36V is ok for the motor, but it will get hot. the brushes can only take so much heat before the plastic brush holders melt.

Yes, but you may have to use a 36v controller. My 24v EVG didn't have one, physically gone when I bought it. So I was using a brushed controller that worked on anything from 24v-48v. I don't know what the stock EVG controller can tolerate. If I opened it up, and saw 50v capacitors, I'd let er rip. But you might have 30v caps in there.

Controller issue aside, yes, you can run the motor at 36v, but you must connect the high temperature cut off wires so you don't cook it off. I toasted one quite fast thinking, " just a short test ride" . Shoulda made it shorter.

The two little wires coming out connect through an on off circuit, such as a key switch or brake cutoff on the controller. so if the motor gets hot, the circuit is broken, and the controller shuts down till the motor cools.

Thanks again, Masters of Knowledge!

I am beginning to see that my 24V Heini is just not going to really hack it, even as a short term solution. Maybe I have to think about stripping down to the frame, derailleur, and body panels/battery compartment.

Maybe go with a gearless rear motor with a geared front motor sometime down the road to make a truly powerful/longlasting hill-climber out of it for the long, steep inclines here in Leadville, CO.

I really like the thought-out design of the EVG controls, etc but I guess I will just keep them as spares for my other EVG.

At least I can share battery packs.

I understand Current is the key to torque and voltage increases speed. Of course, increasing both gives you more of both.
Can I get the hill climbing power I need from 36Volts if I give the bike enough battery and motors (to share the heat load)?

go see if you like the Ecrazyman brushed controllers, 36V500W limit would help protect the motor. ask him for an endless-sphere discount.

but not in leadville. there you have to go with a super small wheel and high turn motor like dogman runs on the trails. 20" wheel.

Cool, I will check it out. Thanks!

there are 2 capacitors on the evg controller's brain board. In some controllers I have opened they were 50v in others they were 35v. there is also a 35 volt capacitor on another board which if I remember right has the relay for the lighting system. the lights btw are limited to 24v. 36 will burn out the resistors in the LED tail light. the headlamp will work at 36v but eventually will melt the plastic reflector.

the 24v hub motors will work fine at 36v as long as you keep the amps reasonably low. I ran one for a year or so w/ a cheap 36v brushed controller which was rated at 500w. speed was increased to a bit over 20mph and hill climbing power seemed to remain about the same. the evg throttle is a potentiometer style and sends a full throttle signal of about 2.7 volts to the evg controller rather than the 5 or so volts a modern controller needs for full throttle. sending 10 to 12 volts through the evg throttle allowed me to use it w/ the new controller. the state of charge lights on the evg throttle are 6v led's which are illuminated by the logic processor in the evg control unit, not a stand alone volt meter like in modern throttles. I ran the 6v signal from the new controller's throttle output to one just so I would have a light on my bars to show that the bike was turned on. you would probably be better off just getting a 36v throttle with soc lights. I liked the way the evg thumb throttle felt and wanted to keep using it though.

as Dogman says, the thermal switch in the evg hub is important. one simple solution, if you go with a modern throttle, is to run the throttle power through the switch, if your motor overheats it will effectively kill your throttle until it cools down. I did something similar but in actuality my motor never once over heated on 36v. I didn't have a watt meter back then to check it so it is highly probable that my "500W" controller was in fact quite a bit lower amps than stated.

if you do decide to replace the heinzmann w/ a modern 48 (or maybe even 36) volt brush-less set up you will find that you won't need a second motor for the front IMO. not sure about the topography in Leadville, CO. but I get up some pretty long steep hills here in Seattle Wa just fine.

for what it is worth, I wrote a post a while back detailing how to fit 36v of lifepo4 into an evg 24v battery case here: http://visforvoltage.org/forum/10456-ev-global-24-volt-ebike-problem

and just for the record, although I wouldn't recommend using SLA, it should (maybe) be noted that 6 6v 7ah sla batteries will NOT fit into an unmodified 24v evg battery case. they will fit in a 36v evg case which is about 1/8 inch wider. 2 12v 7ah in series w/ 2 6v 7ah will just fit in a 24v case. but again, friends don't let friends drive SLA.

DC

Oh yeah, I forgot about the tail lights on the EVG. Headlight can do 36v, but not the tail light. So youd have to put the light on a seperate 24v battery.

Leadville is pretty steep place, so the motor to replace it with if you did would be a slower winding, whether a direct drive or a gearmotor. I bet a Mac 12t at 48v would climb your hills. 10t if the grades are only 10%, but I bet any dirt is steeper by a LOT.

Or heave watts at a 20" wheel bike.

Hey Dogman, do you remember the amperage of the controller you were using when you burnt up the 24v Heinzmann?

DC

Great stuff! Just the kind of info I needed! If you can think of anymore to say, please dump your truck!

Curious thing that maybe you guys can shed some light. I am currently riding my other EVG - 36V stock machine.

It climbs fine with enough battery. But, will eventually give the 3 Beeps every 20 seconds and, if, you keep going, it begins to just wind down on its power (current limiting I suppose) regardless of the battery state. When I stop, I check the motor temp to the touch - not hot. Wait a few minutes and all works fine (but, if I keep climbing, the situation occurs again pretty quickly). I assume this is an overheat protection for the motor but I understand the 36V Heini does not have a thermal sensor in the motor.

If I run around town in Perf Mode and climb a hill for about 6 blocks, I may get the 3Beep as well.

So how is this happening?

I'd say that is normal. I experienced the same situation a few times riding a stock evg 36v up long hills in summer heat. some flashing lights on the throttle cluster, a series of beeps and the motor producing diminished power at full throttle, basically forcing you to pedal harder to maintain speed and to take strain off the hub windings. it never fully shut down and returned to normal shortly after I crested the hill.

There isn't a temperature sensor in the 36v hub but the controller is bit more sophisticated. I always assumed the controller sensed the increased resistance in the motor power leads caused by higher temperatures and powered down the system to avoid damage.

like I say, that was always just an assumption on my part. I was running 12ah of somewhat tired SLA batteries in that bike. I wondered if maybe the controller wasn't just just responding to voltage sag and considered testing to see if a much stronger battery would alleviate the problem. if I remember correctly you are currently running SLA plus a lower amp Lithium pack in parallel? maybe you could run an experiment riding the same hill on just the SLA and then again w/ the addition of the lithium booster pack to see if the bike can climb any farther w/ out complaining with the addition of the extra AH?

DC

When I burned up that heinzmann, I was using a controller sold as a 35 amp. But it was the pre CA days for me, so I never confirmed it was really 35 amp. Used motor, that lasted one day. Could have just been junk. But I didn't have the sensor on it hooked up.

35 amps! so you could have been pushing it up to and possibly past 1400 watts . I have a 24v hienzmann, a 20 amp 36v brushed controller and a steel frame mountain bike just sitting around in my storage shed. I might put it all together w/ just a battery pack on the rear rack and see how it runs at 800w. kind of a pointless endeavor but it could be fun. anyways, it would be nice to work on a project that I didn't have to buy anything to complete for a change. oh wait. if I really wanted any useful data I would need to hook up a CA... but there are some cheaper RC watt meters out there I could get right? so it has already cost me a theoretical $50 and I haven't even unlocked the shed yet. damn e-bikes.

DC

Ok, I broke open my 24V EVG controller to see if there was any components that could not handle 36 volts. See photos.

I'm seeing a couple of capacitors at 35V and a coil at 24V.

If I can't find a 36V EVG OEM controller, I would like to run my horn and lights and battery status using the 24v controller, if possible. And use a different 36v controller to run the Heini motor.

Of course, the best answer for what I want is to find a 36V EVG OEM controller - but, I assume that is impossible.

Yeah, for sure I was likely pulling 1000w spikes. Later, I ran an EVG with similar 24v motor on the same controller with no big problems. With the sensor hooked up, I'd climb a big hill and get the shutoff. But I could ride quite a bit on smaller hills with no problems. Ran the bike on 16 ah of Ebikes CA nicads.

Get a 36v 20 amp brushed controller and run the motor on that. Then run the lights and stuff on a seperate 24v circuit with a second battery or something. Wouldn't take but a 3 ah 6s lipo pack to run lights. You would have to do some significant new wiring for the lights and switch.

Thanks. Could the 24V controller be powered at 36V to run my lights and horn?

cannot make out any components in that picture except the 3 schottky diodes on that heat sink. no idea why they are there, maybe part of the voltage regulated output for the lights.

forget about that light and get a real controller, make sure you get the correct throttle for the new controller if that is not a hall sensor throttle.

And, another question, I was thinking of packing my 36V battery case with 5S batteries (2 in series each group) for my 36V EVG. But, I wonder, is it pushing it to do 6S batteries instead? Better voltage during sag, better performance, less motor heating I assume.

But can the equipment tolerate the higher no-load voltage, I wonder. I would assume it can, since I hear the 36V EVG will run at 48V.

Any downsides to this ? Batteries, etc issues? Eventually, I want to put a front wheel motor on and kick up the voltage to 48V to help chew up those hills here in Leadville.

@dnmum: OK, thanks for the advise. I was planning on a new controller for the motive system.

about using the 24v controller at 36v for accessories, from my experience the short answer is no. I used an old dead controller at 36v (it wouldn't power a motor any longer or give warning beeps etc. but it still worked just to run the lights and horn). I was using a hub w/ an internal controller so in-frame space wasn't an issue. my findings were: the horn developed problems at 36v. it may have just been faulty anyways tbh but for whatever reason at 36v it became intermittent at best. the rear LED light burnt out some resistors and quit working and the headlight melted the plastic reflector after a month or two, diminishing it's beam. it all worked fine for a week or two before developing any problems though so I figured I should warn you.

DC

@dcmotors: Many thanks for your continued advice.