Thread: How to regulate current on a 12volt circuit

Originally Posted by BaronJ

Hi Gazza,

No file the motor plate ! You don't have to try and file out your tapped holes.
Most motor mountings have slotted holes anyway, for the same reason, so you can adjust belt tension !

There is really no room on the motor mounting plate to enlarge the holes as the holes are right on the edge of the base

Originally Posted by gazza2009au

That is awesome thank's!! Jumped on ebay and found a half link straight away it's on order need's to come from WA, i will order another half link once the chain stretches

If the chain stretches that much then it's probably better to take out the half link and insert a full link.

Originally Posted by familyguy

If the chain stretches that much then it's probably better to take out the half link and insert a full link.

Yeah got that bit mixed up lol

Just got the wiring together but no power i either need to charge the lipo, go up to 7 cell, the throttle or speed controller are faulty

Motor spin's when hooked up to 12volt even tho it's rated 24v, i may just run a switch and do without the throttle and speed controller

Tried to upload a pic yesterday but internet was lagging here's the pic, I'm going to see if i can find a 15amp momenterally switch today and wire it up

Yesterday when i connected the motor to 12volt motorcycle battery the wheel spun up and the chain did'nt come off so hopefully i'm winning on this build

https://ibb.co/RSCCgwp

I just had a go on the Ebike guy's gee this little 250watt motor has alot of torque and power, i took the hike out the front gate and onto the street not knowing what to expect i connected the battery than flipped the on switch and the front wheel started doing a burnout so i gave the bike a gentle push and it took off

Now i ride motor bikes a fair bit i grew up riding motocross so i was'nt expecting much, but this ebike just took off going down a very gentle decent i would have hit 30kph easy before i flipped the power switch off, i turned around to come back up the street it started off ok but bound the chain, i had only installed 2 mounting bolts tho and thought the motor was weak and could handle it, with that huge 92 tooth sprocket the torque is incredible so much it flexed the motor mounting plate

I'm going to have to install the other two bolt's and get a video of this thing geez it flies!!!

Anyone know how to calculate electricity usage i tried googling a 24v dc to 240v ac calculator but nothing is coming up just info about power converters

Wanting to know how much it cost to charge my 24v 9ah battery, current electricity charge rate is $0.3175cent per killowatt

I'm coming up with 10cent but that just does'nt sound right sound's way to cheap

I'm hopping to share a video later today after i work on the bike i should atlease have some video of down my street but i don't know if the wobble in the sprocket will bind the chain again going up my street

Here's a video below guy's the run up and down the street is approxamitely 250 meter's and a rough guestimate 1.5% gradent, up hill is faster than walking still a comfy speed without needing to put my feet down i would estimate uphill speed 12kph, down hill speed 27kph+

Sprocket's are not inline and i think that plus a really tight chain is killing it's potentioal

https://youtu.be/3Gk01UahlxU?si=k9NcL_59Hsr8FA0v

To work out how much to charge the battery with a great deal of accuracy will not be possible. That is because a battery can not be fully discharged in most circumstances and recharged. Also knowing the transformer efficiency would be a must.

But as I see the math you have a 24 volt (V) 9 amp hour (Ah) battery. Therefore if we multiply 24 V by 9 Ah we will have 216 VAh or 216 watts (W = V*A).
So if our transformer had 100% efficiency and the battery was completely discharged it would take 216 watts to recharge. At $0.3175cent per kilowatt I calculate $0.07. (.03175/1000X216).

So accounting for transformer losses and the battery not being fully discharged $0.10 would be in the ball park.

Once you get on the road it will be interesting to see how much distance you get for you $0.10. I have a 865cc Triumph. Under normal riding for me on the open road I get 22km to the litre. Fuel was $1.80 per litre on the weekend. So for $0.10 I can buy 55ml of fuel (about 2 shots) and travel about 1.2km.

Steve

Awesome thank's Steve, i plan on running 1 battery 4500mah and riding around the block untill a low voltage alarm goes off, i will record distance on my mobile and let you guy's know

I just need to order the low voltage alarm and battery charger

I'll try get some speed run's shortly using my mobile and see what kind of speed the bike is doing

I just got some number's using a android app which uses satalites and google map

Down hill top speed 26kph which felt really fast on a BMX bike the run was 310 meter's

Up hill was 11kph at the most difficult steepest part of my street and top speed going up the hill was 13kph over 310 meter's

Decline and incline is around 15 meter's over 310 meter's, motor stayed really cool around room temp which is around 22-23c

These were my speed's guy's any idea if i can run 7cell lipo which is 29.4 golts for more uphill omph? Motor is rated 24volt

Just a quick update guy's, tonight i removed the on/off switch found it was a bit deadly if i were riding the ebike across highways and cross streets and if the button were to fuse "on" if i need to stop at a major intersection and the bike keeps moving forward, tonight i purchased a second speed controller and throttle plus a wide spring seat so i can actually ride the bike

Both should be here in 2 working day's

Found my first speed controller had no power output no 5v+ going to the throttle throttle has positive, negative and signal cables the only plug that had power was the brake plug it showed 21.4v i dissasembled the speed controller but could'nt see anything bad on the circuit board, i briefly looked into a DC RC 6 cell brushed waterproof speed controller for cars and boat's but went with the same one i purchased with the ebike motor kit

Will give it ago this week and report the distance on one 4.5ah battery as previously mentioned

Good news about ebikes the power laws had a change in NSW your legally allowed to use a 500watt motor but cannot exceed the old 25kph speed limit