Where did you get the Dewalt battery holders. What were they originally used for? They look like a good mounting solution.
kfong wrote:Is there any interest in complete built boards. I'm thinking of charging $35 for them.
kfong wrote:Lyen, I don't see the flashlights being that useful for a build. No isolation diode and kinda bulky, seems more of a waste of a flashlight just for the connectors. The time to put these boards together, stock the parts and mill out the power tabs is what you are paying for. Just not worth my time if it's less, but I will still sell the bare boards for $5 plus shipping. I have some buyers for the built board already so the price remains $35 finished. Note: I will be stocking the toroid choke needed to keep the spikes from shutting down the BMS. for $10. But rest assured, it all goes to more ebike projects.
jk1 wrote:kfong what inductor are you using to stop the spikes that you will sell for $10 is it off the shelf or hand made ?
What gauge wire are you using i.e what current does it handle. dewalts packs are rated to 15 amps output or 25 ? what gauge suits that?
The inductors i made in the past used 14 gauge enamel coated magent wire that i managed to turn 29 turns around a 38 mm od ferrite toroid.
i need to make some more inductors as i am making more packs and and wondering if i went over kill on the 14 gauge wire for each 36v dewalt pack. what wire diamter are you using ?
As the for the spikes i dont have any at all so it works, but i would prefer a slightly higher inductor value becuase my packs i am actuly using them at the 26v setting and not full duty cycle 34 volts. i can see on my osciciscolpe that the volatga is not flat and spikes up and down under load from 26 to 34. Packs do not cut out though and work perfectly fine its just what i see on the osciscope that i feel is a problem ? to fix it last time i placed 1000uF caps across the output, this has worked well to smooth it out, now the only problem is voltage stays around 34v no load and 26 under load ( some of it is due to sag and some of it is due the caps keeping the voltage high). which is ok except that the motor is rated to 24 volts so i would prefer the volatge was alwasy 26v with or without load.
So im thinking i may use smaller gauge wire and try and put more turns onto it then remove the capacitors on each 36v battery.
My ebike uses 250watt, 24 volt battery ( Single Plug 8AH SLA Battery controller), but I like to use four 24volt dewalt batteries to get better millage. I understand that your board is prepared for 36volt batteries. I am interested to purchase an interface board for 24volt batteries. Please let me know about the price and the purchasing process. Thank you
kfong wrote:Just use the NEG FET and POSITIVE output...
PeteCress wrote:kfong wrote:Just use the NEG FET and POSITIVE output...
Here is my straw man for soldering to those terminals:
- Strip the wire so that about 1/2" is showing
- Twist the stripped section
- Tin the stripped section
- Trim the tinned/stripped section to about 1/8"
- Insert said section into the hole
- Apply the tip of a soldering iron to underside of the board (i.e. the side where the non-insulated end of the power wire protrudes)
- Apply solder to the other side of the board
- Withdraw solder and iron as soon as the solder flows
Does this sound like the proper procedure?
I have no clue as to what wattage iron is appropriate.
The irons I have available to me are 15, 30, 45, and 140 watts.
Can anybody suggest which one will do the job but not fry the board?
kfong wrote:...picture of the battery carrier. You can make something similar out of just wood and flat aluminum rails for the support.
kfong wrote:Update, looking for a suitable inductor.
kfong wrote:I know LI-ghtcycle had success building his own with just hand tools
http://endless-sphere.com/forums/viewto ... =3&t=14912
kfong wrote:Try adding more windings that will increase the inductance. You still have room in the center, wires can overlap. The Toroid is smaller...
kfong wrote:I hadn't tried just using metal rings. That's a cheap solution. Ferrite is suppose to have better properties but as long as you get results. The original design by Neodymics had a 300uh inductor. Since I don't have an inductance meter. I just wound as much as I could. As long as it works for you. You can have more inductance, just as long as you meet the 300uh minimum. Its sole purpose is to reduce the spikes going back to the batteries, so if the BMS doesnÃ¢â‚¬â„¢t shut down then youÃ¢â‚¬â„¢re good to go. The only other time it shuts down is when you draw too much current. You will get a pulsating effect. This is different from the spike shutdown.