charging prob

[Admin]

i just bought a compact char-g from k-mart

it was a 40 mhz one but i put on the white skyline case on it

i did a led mod on it and i can’t charge it any more

when u put the car on, the led on the controller doesn’t go on

plz help

[Admin]

it may still be charging even tho the led isnt work … try changing the batteries in the controller too

[GT-ahh]

mine did that after i dismantled the controller…i dismantled again and put back together and it magically worked

[PandaBear]

Quote:

Originally posted by dafidav on 26October2002

it was a 40 mhz one but i put on the white skyline case on it

i did a led mod on it and i can’t charge it any more

when u put the car on, the led on the controller doesn’t go on

Is the LED connected to the battery, or is it powered by its own powersource?

If you had to connect it to the BCG battery… you might have busted some wire from battery contacts to the board.

To check if your TX charger is working… mine seems to flash its ‘charge’ LED for a splitsecond the moment you switch it on. If it doesn’t flash, but the car controls are still working then the charger is broken.

[Admin]

yea the guy above me is right! are u using a cell battery? if u arent use one of those to minimize space.

[Admin]

Also if you have connected a led to the car, have you connected the led around the right way? if not the led can kill itself and creat a short thet will short out your battery

[PandaBear]

Quote:

Originally posted by -ccw- on 06November2002

Also if you have connected a led to the car, have you connected the led around the right way? if not the led can kill itself and creat a short thet will short out your battery

no can do:- LEDs are diodes and they DON’Tconduct if they’re put around the wrong way. (You’ve got a 50:50 chance…:smiley1:if you don’t know what you’re doing.)

But they DO conduct 100% with *minimal* resistance when put on the right way. Chances are, if the LEDs are tapped straight onto the BCG battery and the charger is working fine – then they might be draining all the charge current that’s going in. Thus the battery never gets charged.

If the LEDs are connected to the battery, remove them and see if the car works again.

[Impreza]

Once again I agree with PandaBear (why are you always right?). Are you using a 3 V lithium battery to power your LED’s or are you using your NiCd to run them? You may want to, if you put a switch in your circuit, turn off your lights and see if it charges then? Need more info…

[Admin]

How can the LED drain all the current, they only draw about 20 odd milliamperes.

[PandaBear]

Quote:

Originally posted by jamiekulhanek on 07November2002

How can the LED drain all the current, they only draw about 20 odd milliamperes.

The LED by definition has no resistance when ‘on’… so it can (theoretically) draw every mA of current you try put into the battery – like charging a shorted battery. Too much amps thru the LED and it blows up.

Put the LED the other/wrong (‘off’) way and its resistancebecomesinfinite. It will not conduct, it will not light up when ‘off’.

Then again, if the LEDs are connected ‘on’ to the battery, then when you plug on the charger the LEDs should light up too. Does it?

[PandaBear]

Quote:

Originally posted by Impreza on 06November2002

Once again I agree with PandaBear (why are you always right?).

Amazing what you can learn in the skool-o-hard-knocks… :smiley2: all those skills much more useful and lots more practical than everything I ever learnt in school or uni.

eg… in uni they taught us how to program in C and Pascal (sigh!).

[Admin]

Hate to tell yoy but if you connect a diode the wrong way around for too long or at too high a voltage a diode will kill itself ( depends on what type of diode) have look in any electronics textbook.

anyway I only said it as one posability,

and led a special diodes and when used with out a resister or current limiting device you can expect to see a led draw infanit current ie a short. the only reason most people get away with putting a led direct to a battery is that the voltage is faily low andd/or the internal resistance of the batery is hight enough to limit the current going into the led. Don’t beleave hock up one of your Expensive blue led up toa 9v battery with out a resister and see what happens to $7 worth of led :smiley15:or if you want to test my low voltage case, get yourself a lab powersupply, set it to 1.2 volts with no current limiting and stick the led in and see what happens.

have fun

[PandaBear]

Quote:

Originally posted by -ccw- on 08November2002

Hate to tell yoy but if you connect a diode the wrong way around for too long or at too high a voltage a diode will kill itself ( depends on what type of diode) have look in any electronics textbook.

oh yea, totally agree with you. If the voltage is too high across a reversed diode then funny things can happen too. Usual safe threshold depends on the LED, but usually <6V is pretty safe.

Circuits actually use some diodes in reverse for this special property (ie they don’t conduct up to certain voltage, then they conduct). They’re called zener diodes.

Quote:

Originally posted by -ccw- on 08November2002

and led a special diodes and when used with out a resister or current limiting device you can expect to see a led draw infanit current ie a short. the only reason most people get away with putting a led direct to a battery is that the voltage is faily low andd/or the internal resistance of the batery is hight enough to limit the current going into the led.

Yup, that’s definitely spot on the money too!

Little button cells won’t push out enough current to hurt a LED, especially if you put several in parallel. Anything capable of more current, like a nicad, you should have some resistor in line. What value of resistor – you need to work out given the voltage & intended current.

LED’s brightness is also proportionate to their colour and current – check their specs. More current = brighter… up to the max recommended limit.

Quote:

Originally posted by -ccw- on 08November2002

have fun

I have!! :smiley2:

Ever seen a LED blown up so bad, the top dome has flown off??! :smiley3:

[Admin]

i had a 3 volde blue super bright l7 led hooked up to a 12 volt and it hasent blown yet key word yet. but i agree with ccw i killed alot of led’s on my car but i have no idea why the l7 is lasting so long. i would say screw the charger on your controle and go to a direct charger. i use a intell peak pulse charger i like it becouse it charges bolth nicd and nimh and i allways disscharge my nicd’s after i use them and before i charge them becouse nicds do devlop cell memory whare if they dont get a full charge the wont charge fully the next time so conditioning your cells is worth wile but nimh cells dont get cell memory. but theres some info on stock and box stock racers who cant use a nimh cell.

if i were you i would jast make a direct charger useing 3aa’s or use a rc car charger just make shure it has a adj. charge rate or a trickle charge.

[Admin]

make shure thecharger points on the bottom are in right becouse mine did that and thats what was wrong with it. the – slid back about a 2mm and itwasent makeing contact

[Author]

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