...let me try! [low-cost street bike] -- last steps...

[silvocross]

Get hold of a huge pile of used laptop battery for free? This could work, you have a lot of room in that frame for a huge battery! 1-2c cells would not be a problem if you can build a 1kw+ pack

It would be cool, the main prob is to find out all this batteries for a good price, at the moment looking for this RC packs: http://www.ebay.it/itm/11-1V-3S-2200mAh-20C-LiPoly-Battery-for-Trex-450-helicopter-free-shipping-/140719672317?pt=RC_Modellbau&hash=item20c38bcbfd#ht_2004wt_1189
I could dissassemble them and wire up a 12s 8.8Ah pack for about 100€, it isn't really too much, but at I'm a student and at the moment I really can't buy them (I shoud also buy a 12s lipo charger, so almost 120€ more).
Maybe I'd look for a sponsor

[auraslip]

please don't buy lipo off of ebay. 4s packs from hobbyking are $25. You won't find anything cheaper than that, and the quality will at least be assured.

[silvocross]

I'm back!

new transmission set:



then I made the upper pvc cover, and glued foam to the aluminium sides to avoid noise:





and here the washing machine!






finally, I found out 4 old and completely dry SLA's, so I'm now trying to resurrect them. I know I shouldn't, but... let me try!

[Byte]

Which pitch are those gears? And how many teeth are they?

[silvocross]

Which pitch are those gears? And how many teeth are they?

they're module 1.5mm, so pitch is 4.71mm => 0.185"

the setup is 17/60 x 21/90 = 0,066

[Neovin]

Disclaimer: you should not try this, will result in death if not properly used!!!!!!!!

Ohh reviving batteries, have you tried using AC Rectified through a full bridge and light bulb (60watt) then DC side into battery, it has saved a few sla's for me

_____ _________
/ /
AC---------------------- Bulb ----------------- rectifier /--------------------------------------- positive
/ /
_____ / /
/ / This side will kill if handled whilst powered!!!
/ /
AC------------------------------------------------/ /---------------------------------------- negative
_________

I cant stress enough don't do this if you don't understand this, but this can resurrect flooded, sla, agm and desulphate as well as charge nicd and nimh batteries up to 240v

[silvocross]

thanks neovin, I'll try this for sure!

[Kin]

Quick thing- you still need to refill the electrolyte before doing that ACrectifier suggestion.

My guess is that the rectifier is the same thing as the "pulsed voltage" devices. The response has been very mixed as to whether it's sucessful or not at reviving batteries, but the design is to break the precipitated sulphate crystals off of the lead cathode.

But the pulsed voltage stuff will need to be done after you get the general operation of the SLAs back to life (namely, restored electrolyte).

[Neovin]

yeah you correct there, you can replace the bulb with a motor run capacitor and play with the values to get a fixed amperage pulse, it does make it a lot more efficient too.
After treating an old 24v sla that i received drained down to 11v, it doubled the range of the scooter. another thing that can help is to find a way to fast discharge that helps to get the lead back onto the plates.

here's a link to a brilliant website:
http://batteryuniversity.com/learn/

,Neo

[silvocross]

ok, I tried your method (with a light bulb), now it's time to whait and see if the battery mantain the charge.

thanks!

[cwah]

a quick step ahead...

The brake isn't arrived yet, so today I made a small rear light.
I didn't want to discharge in different ways the 4 batteries using 12V lights, so i run 15 LED in series and a 400ohm resistor at 50V, the light takes about 20 mA (so 1W) with a very good lighting power.

in the picture you can also see the charging plug:

That's a nice arrow. Where did you purchase the board, led and resistors? I want the same

[silvocross]

Oh, it's quite simple to do that light.

- I just bought 14 red 3V LED, for example http://www.ebay.it/itm/10pcs-Car-3mm-Re ... 2900wt_956

- then you need some resistors, I used a total of 400ohm, you can use one of these: http://www.ebay.it/itm/1-4w-Watt-0-25W- ... 5ae44bcdb1

- you can assemble the light on a simple prototype board, like this: http://www.ebay.it/itm/New-5-PCS-Bread- ... 27c6bb209e

note that this setup is perfect for using a 40 - 55V power supply like my series of 4 SLA.
for other voltages you need to rearrange the setup, but it's really really simple.

PS: I'll be in London this weekend!

[cwah]

Thanks for all these links. I think I may give a try with my 74V setup. I suppose I'd need 24 led

What are the resistor for? Why are they necessary?

ps: That's great that you're in london. Planning to see some specific place? be careful it's going to rain

[silvocross]

You're right, you need 24 LEDs for your setup.

Usually LEDs can admit a maximum of 3.15V, so 24 x 3.15 = 75.6V (when connected in series).
Because of their very low internal resistance, they have to be connected in series with a resistor to limit the current, otherwise current will get really high.
LEDs usually accept a current between 10-30mA.

You also have to add a resistor to pull down the voltage in the circuit. when fully charged, you can reach 78V, so the resistor has to manage 78 - 75.6 = 2.4V.
Finally, the resistor value should be 2.4 / 0.020 = 120 ohm (Ohm's law)

Be careful to always check the LED datasheet to be sure about their voltage and current parameters.

...taking off now!

[Neovin]

Bump, how are you getting on?

[panurge]

Neovin, are you referring to the battery resurrecting procedure? or you missed this one, perhaps?
viewtopic.php?f=28&t=42262

[silvocross]

Hi!

The project is definitely finished and archived, I just started a new improved build based on the experience made with this first bike.

It should be fun, but the construction has dramatically slowed down because I moved to another city for university reasons.
By the way, it's not completely stopped, I'm designing the electronic interface and... I can say it, you'll be surprised

Sent from my Nokia 3310 using Endless Sphere