effects of over voltage on a controller

deacon

deacon

minor bike philosopher
Has anyone tried a just slightly hot battery pack on a Halls type controller. Here is what I want to do and it is just an experiment.

"I want to run my 36v sla battery pack down to about 36.5 volts because that is where the controller shuts down.

I want to add a 6volt battery that has been drained to the pack. There by making it a 42volt pack.

Then i want to charge the pack with a 36volt charger which charges at 41.5 volts. If I'm being stupid someone tell me because I'm just curious to know what will happen.

Ordinarily I would just do it and report the results but this is just curiosity. Since I have no idea what, if any, benefit it would be to have the over volted pack. Since I am going to charge it with a 36v charger. It might not even raise the voltage of the pack above what it is normally would be.

The only thing I noticed was the controller starts out at 41.5 volts for a burst of a half second then drops to 39.7 or less. I wondered what would happen if it stayed at 41.5 for a while.

Since the halls controller costs fifty bucks or so it's a bit much to just let idle curiosity take over. So if you have tried it or know someone who has let me know. Thanks.
 
Boredom is a killer.

I got so tired of not building bikes that I checked all over the net to see if anyone had done what I wanted to do. I found some forums that said sure you can do that. I found others that said no you will cause it to overheat.

"The main opinion was that if it was a problem the controller would just turn itself off. Nobody addressed the problem that it might just be a wash, so I decided to build a pack and see what happened.

First I pulled the pack that kind let me down a little and tested each battery, since they weren't all bought at the same time. Two of the batteries were within a hundredth of a volt of each other. The third one was a couple of tenths low. So I swapped it out for a battery from the donor pack I planned to use for my new over volt pack.

I also loaded a 6volt battery into the pack and reassembled it. The thing read 45 volts. I was a little worried about that but I took off with it. It went the first mile really well. It had a little more zip and a little more torque though that wasn't the purpose of the new pack.

I almost home when it shut down. I thought I had damaged the controller. Then I found out the battery stopped putting out. I took it back inside and tested the wiring. I found a bad soldier joint so I fixed it and tried again. The battery pack read 44 volts so it the 36 volt charger never came on. It worked fine that time so I had two miles on the pack already. I took off with it and a spare.

I rode it several miles and it performed better than it had ever done before, but that wasn't the purpose of the build. I think it went about seven miles on the pack which was nice but still I haven't been able to really test for the reason I built it.

I can't get the battery pack down to a low enough voltage to test what will happen when the pack is charged with a 36volt charger. Instead of starting with 43 or 44 volts. I expect it to start with 41.5. I am hoping it wont drop down one or two volts before I get out of the drive. But I'm beginning to wonder if it matters what the volt drop is. It seems to be about the amps more than the volts.

The motor had been shutting down at 36.9 this configuration shut down at 39 volts. So there are a lot more tests to be run. But it is something to do.
 
Yes you can run a 36v halls effect controller without damage at 42v for sure I have no idea about anything higher.

The problem with the 42volt battery pack is the charging. You can not use a 36v charger just ain't happening. It actually drains the battery over time. I caught mine before it went into cardiac arrest.

So I'm back to 36v until I find some way to charge the battery or until I get up enough devil may care to try it at 48v.
 
I couldnt stand the suspense I built a 48v battery pack. I am charging it now. Tomorrow I will either burn up the controller or over heat the motor or run the bike with a hotter pack. Who knows what tomorrow will bring. Ah the shadow knows.
 
it will be interesting to hear you results on over powering an electric motorized bicycle deacon. be careful is all i can say
zpt
 
Today I rode the 36v 800 watt halls effect hub motor with everything stock except the battery pack. I installed a 48 volt sla pack and took off. I fully expected to be buying a new controller tonight, but I rode it ten miles up and down the hills in HIGH POINT NC.

The bike of course goes faster and pulls harder. So I learned something not about over volt powering bikes so much but about the size motor for my needs. Well more about my wants I guess.

If you are riding something as heavy as a trike with two heavy sla battery pack and you want to pedal some on the hills Then the 36v 500 700 or 800 watt is for you The watts has more to do with torque I think than anything else. At 800 watts I could comfortably pedal most hills.

Now if you want to ride with the big boys (Scooters) AT least 48 volts is the trick. I guess I'm running 1000 watts as well since the amps stayed the same. Here is what the heavy trike with the heavy load of batteries seems to do well.

It starts from a dead stop and picks up pretty well even up moderate hills. It climbs short hills like a mountain goat especially if you get the momentum up before you get to the hill. Going down even a slight incline with the motor full on, it gets scary fast for me. Then you kind of have to remember I broke seven bones on a motor bike two years ago. Six months ago I had a trike go over backwards on me. so I think I scare a little easier than most.

The 48 volts seems to pull and run at just the right speed for a scooter for me. So if the trike get totaled (which it almost did coming home today) I would build a bike based scooter next.

I would buy a 48v hub motor though.

Then build a 3 wheeler like the one in the tread my mobility scooter concept.

Quite often I see 'well used' road bikes at the thrift store where I buy my used bikes to strip out for parts. I think I could make the hub motor work in the front fork. Then remove the rear wheel and add my home made trike type rear end. I learned a lot messin' with that thing.

So I don't recommend it, but I am going to power my trike with 48volts, but carry a 36v 7ah rescue battery pack as well. This counts as one of my successes.

PS I wonder if there truly is a 48v 1000 watt kit, or is it just the 36v kit in a different box.
 
a lot of the electric motorized bicycle kits are multi voltage, the magic pie and smart pie for example are made for 24v, 36v or 48v depending on what you need,
 
I am tempted to try 24 volts on this one. Just to have that option if I need to work out by pedaling a lot.

I really expected to be buying a new controller at least but it seems to work just fine.
 
are you like me deacon and have every good intention of getting some exercise on my motorized electric bicycle however i can't keep my thumb of the throttle, i do have a very strong thumb now though lol
 
Exactly...

Also I am a curious son of a gun, so I do get some intellectual stimulation, when I ride along thinking "What if" This morning for instance. since I don't have a 48v charger but I have a really nice 24v golf cart charger. Couple of days ago I rigged the battery pack from the trike so I could have two 24v bats in parallel then after the are hot I move a couple of wire around and have it go 48. It is in the basket so I think I will just have to try it at 24 volts to see if it is hot enough to move the trike. Not that I would ever use it at 24volts.

I got to thinking about the controllers during this experiment. I always thought they haa shut off control based on low voltage but obviously not. If they did they would run a 48v pack in a 36v controller way past the safe point per battery. Mine still shut down while the battery is still safe. At about 48v I think. At least it did with the 42volt battery I ran for a day or two. So it must be based on Amp drain not voltage that shuts it down. That would make sense and explain why it would run a 48v in a 36v controller. It the 24v will move the bike today then I will know it is the Amps not the volts they react to.
 
The last up date: I tried it at 24 volts it wouldn't run at all. Then I rewired it to 48 volts and took off to the lake my most challenging ride.

The bike runs stronger at 48 volts for sure. It climbs the steep hills better but still requires some help. So while there is improvement under the worst conditions it was less than I hoped for.

The lake is almost 7 miles round trip. With a 36v 12ah battery pack I am withing sight of my house when the pack pretty much dies.

With the 48v 12ah I lost power at exactly the same places. "So I decided the 48v battery just wasn't worth the aggravation. I don't mind the small amount of difference in the pedal factor. It's actually good for me. The slightly slower speed only bothers the people behind me.

So I rebuilt the packs again and now I am back to square one but I know. If i want to build a three wheel electric scooter based on a bicycle frame I am going to need more than 48 volts.
 
Most controllers can handle 48 or 60v. More than that you might need a better controller and be carefull with voltages over 60v can electrocute you
 
Since I didn't burn the controller I have decided to rewire the battery pack in my tricycle to 48volts. I went back to 36v but found it less responsive than at 48v . Since I have the batteries laying around anyway why not. I can put together a 24ah pack which is more than enough for anything I would want to do with the trike.

The ability to constantly reinvent the trike is one of the benefits of the sla pack. When the current SLA pack of eight 12v 12ah batteries goes belly up, I will have to reinvent the battery I expect. I have been looking at some 12v 15ah lithium units. I might go that direction and wire my own battery packs just as I do now. I would just have to be a heck of a lot more careful with them wiring. Shorting those out could get pretty darn expensive.
 
Since I haven't burned the hub drive up yet, I thought I would try something else. First of all both 36v and 48v packs work equally well. 48v of course has more speed. But when running a pure 48v I found myself running it at less than half throttle most of the time. So I thought, why not a 36v battery pack for most of the time, but a 48 pack for the once in a while I want to run more or less with the traffic.

So I wired a 48v pack and a 36v pack. The 36v is 24ah and the 48v is 7ah and I'm on my way now to buy a three way wall switch. Hopefully I can use it backwards to connect two power supplies to one outlet to the controller. Of course I will have to test the heck out of it before I hook it to the controller.

It should be an interesting experiment. I wont have a charger for a couple of weeks so I won't be able to do anymore now than test it.
 
Okay it worked in that both legs have power and move the bike. Since I don't have a 487v charger yet, I'm going to hold on actually running it. I'm sure some time tomorrow I will give it a try somewhere just to see how it works.
 
Even without a way to recharge the batteries in the 48v leg, I took the trike out for a test. It's fun to play with. What I did was: at the spots I just cruise or have very short not too steep hills, I ran the 36v circuit. When I got to the four really steep hills of my short test track I went to the 48v circuit.

The result was that the ride was very pleasant. It climbed the hills very well. I didn't need the pedal assist at all. There was a big difference in the 36v battery drain over my ordinary test, which was pretty much what I expected. I guess it is true that most of the battery drain is on the hills.

The drain on the 48v battery circuit, I can't judge now, since I'm not sure the charge on the batteries to start. It does seem as though the drain was less than half of the small capacity batteries. That means they would be good for an acceptable amount of distance.

I'm going to do more tests to determine how high of a capacity 36v pack I need, if I take the heavy drain factor out of it. It should be interesting.
 
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