RCCrawler Forums

AYKBOBCAT · 03-25-2005, 12:33 PM

Hi guys.... This is my very first thread... I am not so new to R/C but I am definitely to crawling..... Lots of cool stuff here! Man!....

I have recently bought a charger that can charge up to 25 cells, does the lipo lead-acid and so on.... Of course this thing is made to be plugged on a car battery.

Now I found information on how to convert a computer power supply to give a clean 12v source. Very cheap. I got one for free.

In my charger instruction book it says that it need a 12v 12A (continuous) source to be used with a power supply. The one I got is 10A on the 12v line. Is this a problem? Would the charger use 12A only when charging very big packs (like 25 cells)? I don't plan to use more that say 8-10 cells anyway (super rooster). I don't know much about electronics so I don't want to fry my charger...

I am also thinking about using the 5v source to power up my receiver for testing...

Any input would be greatly appreciated.

:neutral:

skid · 03-25-2005, 01:12 PM

I'm using a old power supply for my charger. It says 10 amps but I think thats peak. I can charge a 8 cell nimh pack at 3.5 amps and the power supply voltage will hold 10.5. More cells will need less charging amperage to maintain the input voltage. Works great other than limiting my charge amperage, and for free, can't beat it.

Ace · 03-25-2005, 01:45 PM

Most computer power supplys need to sense a load before they will turn on. Your internet instructions must mention ways to deal with that.

As far as 10A supply running a 12A charger. It should work if you don't charge at high rates.

My triton will charge two packs in series at 5 amps. The load from the 12V source will be higher than 5 amps (more like 10amps)

So yes it should work, but just don't crank it up.

Jeckler · 03-25-2005, 01:58 PM

I used one for awhile. It was neat to get it going, but it ended up dying a while later. The money spent in supplies to convert it would be better spent getting the right kind in the first place, IMO.

Ace · 03-25-2005, 03:07 PM

I gotta agree.

I got my 10A 12V powersupply off ebay for about 25 bucks. Try searching for "Cosel 12"

SPEED_RACER · 03-25-2005, 06:39 PM

i have one of the cosels as well and works great.mine is rated at 13 amp

AYKBOBCAT · 03-26-2005, 01:09 PM

The PS I got is generating 10A max. My charger is charging at 5A max so do you guys think the PS is strong enough? The charger instruction manual says 12A but that thing can charge up to 25 cells so even if I charge two 9 cells pack at once it is still not a maximum capacity. Let me know I'm not to good with electronics.... :?

SR5Dave · 03-26-2005, 03:44 PM

Quote:

Originally Posted by AYKBOBCAT

The PS I got is generating 10A max. My charger is charging at 5A max so do you guys think the PS is strong enough? The charger instruction manual says 12A but that thing can charge up to 25 cells so even if I charge two 9 cells pack at once it is still not a maximum capacity. Let me know I'm not to good with electronics.... :?

I would think it'd be fine... Run it and see what happens

DSpy · 03-27-2005, 08:24 AM

Not too sure about current. But your PC PS should be 400W and above.

Here's a link to converting your PC PS to charger PS.

Converting PS

Hope it helps.

gemiller · 03-28-2005, 07:28 AM

Quote:

Originally Posted by DSpy

Not too sure about current. But your PC PS should be 400W and above.

Here's a link to converting your PC PS to charger PS.

Converting PS

Hope it helps.

Very interesting and informative, but do you think that we really need 400watts?(this isnt a retorical questoin either, it kinda sounds like it) what do you think the lowest watts necesary are?

Ace · 03-28-2005, 08:15 AM

12volts * 10amps is 120 watts.

400 watts on a computer supply includes the 5V and 3.3 V lines. The amperage on the 12V is all that matters for running a charger.

I'd get a Cosel. Mine you can adjust the volts up to about 14. Car batteries are actually around 13.8volts when charged. The extra voltage helps older chargers charge 8 cell packs (like transmitters)

gemiller · 03-28-2005, 08:36 AM

Well I plan on saving for a really nice psu for rc equipment but for now im just charging boring stick packs for my rotostart and ezstart and tlt lol so ill use an old psu i have from a comp for now. Thanks guys, good thread!

gemiller · 03-28-2005, 08:58 AM

Hmm I went out to my junk heap of old comp stuff and found a psu over 120 (its 150) only problem is its older than the 20 plug setup. I already did the 12 v thing, by taking the yellow/black wires. but my problem is instead of one 20 pined plug i have 2 6's with colors in this order: (1st plug: black black blue yellow red orange)(2nd plug: red red red white black black)

Does anyone know what wires i would use to finish this part:
20 way long and thin one:

Pick out the green wire and one of the black wires, cut them off the plug, strip them and join them together. Insulate the join with tape.

Pick another black wire, cut if and connect it to the common wire on your stop/tail lamp.
Pick a red wire and connect it to the stop (21W) section of your stop/tail lamp
Pick a yellow wire and connect it to the tail (5W) section of your stop/tail lamp
Make sure all the joints are insulated properly.

Plug in the power pack and the fans should start. The lamp should come on too, the stop filament (the thicker one) should be relatively dim and the tail one should be bright.

AYKBOBCAT · 03-28-2005, 11:59 PM

Yesterday I tested the charger to figure out how much it needs exactly. I was charging a 9 cells battery at 5A. My charger was connected directly on the car battery with the tester. It never drew more than 8A from the car battery. So I guess my computer power supply (12v 10A) is good enough. I could not charge two packs at one I suppose though.

SPEED_RACER · 03-29-2005, 02:07 PM

you could do 2 if you lower the charge rate so the load of the 2 are less then 10 amps.

kevinlongisland · 03-30-2005, 07:41 PM

i've used a computer power supply for 2 years or more. but i use it for allot of other things because with the plus and minus voltages you can make a lot of different voltages for testing, etc.

some power supplies will fry if you turn them on without a load. i did it once and fried a really nice ps. i just put a low wattage high resistance resistor across the terminals. something like 20K ohm. i think you have to load the ground to +5v terminal.

03-25-2005, 12:33 PM	#1
AYKBOBCAT Rock Stacker Join Date: Mar 2005 Location: Canada/Netherlands Posts: 70	Using a computer power supply to power up my charger.... Hi guys.... This is my very first thread... I am not so new to R/C but I am definitely to crawling..... Lots of cool stuff here! Man!.... I have recently bought a charger that can charge up to 25 cells, does the lipo lead-acid and so on.... Of course this thing is made to be plugged on a car battery. Now I found information on how to convert a computer power supply to give a clean 12v source. Very cheap. I got one for free. In my charger instruction book it says that it need a 12v 12A (continuous) source to be used with a power supply. The one I got is 10A on the 12v line. Is this a problem? Would the charger use 12A only when charging very big packs (like 25 cells)? I don't plan to use more that say 8-10 cells anyway (super rooster). I don't know much about electronics so I don't want to fry my charger... I am also thinking about using the 5v source to power up my receiver for testing... Any input would be greatly appreciated. :neutral:

03-25-2005, 01:12 PM	#2
skid Rock Crawler Join Date: Nov 2004 Location: in a basement in Kalispell, MT Posts: 857	I'm using a old power supply for my charger. It says 10 amps but I think thats peak. I can charge a 8 cell nimh pack at 3.5 amps and the power supply voltage will hold 10.5. More cells will need less charging amperage to maintain the input voltage. Works great other than limiting my charge amperage, and for free, can't beat it.

03-25-2005, 01:45 PM	#3
Ace Rock Crawler Join Date: Apr 2004 Location: Longmont, CO Posts: 901	Most computer power supplys need to sense a load before they will turn on. Your internet instructions must mention ways to deal with that. As far as 10A supply running a 12A charger. It should work if you don't charge at high rates. My triton will charge two packs in series at 5 amps. The load from the 12V source will be higher than 5 amps (more like 10amps) So yes it should work, but just don't crank it up.

03-25-2005, 01:58 PM	#4
Jeckler Rock Crawler Join Date: Jan 2004 Location: Round Rock, TX Posts: 597	I used one for awhile. It was neat to get it going, but it ended up dying a while later. The money spent in supplies to convert it would be better spent getting the right kind in the first place, IMO.

03-25-2005, 03:07 PM	#5
Ace Rock Crawler Join Date: Apr 2004 Location: Longmont, CO Posts: 901	I gotta agree. I got my 10A 12V powersupply off ebay for about 25 bucks. Try searching for "Cosel 12"

03-25-2005, 06:39 PM	#6
SPEED_RACER Quarry Creeper Join Date: Nov 2004 Location: MANVILLE Posts: 413	i have one of the cosels as well and works great.mine is rated at 13 amp

03-26-2005, 01:09 PM	#7
AYKBOBCAT Rock Stacker Join Date: Mar 2005 Location: Canada/Netherlands Posts: 70	The PS I got is generating 10A max. My charger is charging at 5A max so do you guys think the PS is strong enough? The charger instruction manual says 12A but that thing can charge up to 25 cells so even if I charge two 9 cells pack at once it is still not a maximum capacity. Let me know I'm not to good with electronics.... :?

03-27-2005, 08:24 AM	#9
DSpy Newbie Join Date: Mar 2005 Location: Singapore Posts: 24	Not too sure about current. But your PC PS should be 400W and above. Here's a link to converting your PC PS to charger PS. Converting PS Hope it helps.

03-28-2005, 08:15 AM	#11
Ace Rock Crawler Join Date: Apr 2004 Location: Longmont, CO Posts: 901	12volts * 10amps is 120 watts. 400 watts on a computer supply includes the 5V and 3.3 V lines. The amperage on the 12V is all that matters for running a charger. I'd get a Cosel. Mine you can adjust the volts up to about 14. Car batteries are actually around 13.8volts when charged. The extra voltage helps older chargers charge 8 cell packs (like transmitters)

03-28-2005, 08:36 AM	#12
gemiller Rock Stacker Join Date: Feb 2005 Location: Pine Grove Posts: 76	Well I plan on saving for a really nice psu for rc equipment but for now im just charging boring stick packs for my rotostart and ezstart and tlt lol so ill use an old psu i have from a comp for now. Thanks guys, good thread!

03-28-2005, 08:58 AM	#13
gemiller Rock Stacker Join Date: Feb 2005 Location: Pine Grove Posts: 76	Hmm I went out to my junk heap of old comp stuff and found a psu over 120 (its 150) only problem is its older than the 20 plug setup. I already did the 12 v thing, by taking the yellow/black wires. but my problem is instead of one 20 pined plug i have 2 6's with colors in this order: (1st plug: black black blue yellow red orange)(2nd plug: red red red white black black) Does anyone know what wires i would use to finish this part: 20 way long and thin one: Pick out the green wire and one of the black wires, cut them off the plug, strip them and join them together. Insulate the join with tape. Pick another black wire, cut if and connect it to the common wire on your stop/tail lamp. Pick a red wire and connect it to the stop (21W) section of your stop/tail lamp Pick a yellow wire and connect it to the tail (5W) section of your stop/tail lamp Make sure all the joints are insulated properly. Plug in the power pack and the fans should start. The lamp should come on too, the stop filament (the thicker one) should be relatively dim and the tail one should be bright.

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03-28-2005, 11:59 PM	#14
AYKBOBCAT Rock Stacker Join Date: Mar 2005 Location: Canada/Netherlands Posts: 70	Yesterday I tested the charger to figure out how much it needs exactly. I was charging a 9 cells battery at 5A. My charger was connected directly on the car battery with the tester. It never drew more than 8A from the car battery. So I guess my computer power supply (12v 10A) is good enough. I could not charge two packs at one I suppose though.

03-29-2005, 02:07 PM	#15
SPEED_RACER Quarry Creeper Join Date: Nov 2004 Location: MANVILLE Posts: 413	you could do 2 if you lower the charge rate so the load of the 2 are less then 10 amps.

03-30-2005, 07:41 PM	#16
kevinlongisland The Wheels Keep Turning Join Date: Jan 2004 Location: Phoenix, Arizona Posts: 2,831	i've used a computer power supply for 2 years or more. but i use it for allot of other things because with the plus and minus voltages you can make a lot of different voltages for testing, etc. some power supplies will fry if you turn them on without a load. i did it once and fried a really nice ps. i just put a low wattage high resistance resistor across the terminals. something like 20K ohm. i think you have to load the ground to +5v terminal.

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