R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 05-02-2013, 10:33 AM   #286
Tech Addict
 
Team Grid RC's Avatar
 
Join Date: Sep 2010
Posts: 631
Trader Rating: 3 (100%+)
Default

Quote:
Originally Posted by MUDVAYNE View Post
I will be charging a 1s pack for WGT. I was thinking the pyramid 30 amper would work, but then again I would like to have the right equipment the first time.
Your TP charger will shine with 24V or more input, but 12V defeat its potential. The higher the input voltage you feed the TP charger or any other amperage charger, the lower the current draw during charging and the cooler the power supply will run and thus better efficiency.

You can consider an EFuel power supply which are low cost turnkey power supplies with several models that will give you the required input amperage and voltage.

EFuel 30A 15-18V http://www.buddyrc.com/efuel-550w-30...-with-pfc.html

EFuel 60A 15-24V http://www.buddyrc.com/efuel-1200w-power-supply.html

There a also other power supplies as well.
__________________
www.GridRC.com
Team Grid RC is offline   Reply With Quote
Old 05-02-2013, 10:50 AM   #287
Super Moderator
R/C Tech Elite Subscriber
 
Join Date: Oct 2007
Location: Rochester Hills Michigan
Posts: 7,232
Default

Quote:
Originally Posted by MUDVAYNE View Post
I will be charging a 1s pack for WGT. I was thinking the pyramid 30 amper would work, but then again I would like to have the right equipment the first time.
Should be fine for 1S. The highest charger output would be around 30A x 4.2V = 126 watts. Adding some to run the charger itself (efficiency) probably puts the input power requirements somewhere in the 150 to 160 watt range.

Assuming the Pyramid is around 13.8 volts, that's less than 12 amps. While higher voltage is nice, it's hardly needed for your current application. Just be aware of the limitations if you do have larger batteries in the future, buddy wants to try it out, etc.

Also I believe the TP, like most of the big boy chargers, can be programmed to limit the power to the supply being used to prevent issues. I'd probably set it for maybe 20 amps or so max, or even a little less to be safe.

Of course as you mentioned it does need a boat trailer to drag it to the track.

Last edited by Dave H; 05-02-2013 at 11:16 AM.
Dave H is offline   Reply With Quote
Old 05-02-2013, 03:33 PM   #288
Tech Elite
 
LOW ET's Avatar
 
Join Date: Dec 2007
Location: cleveland, ohio
Posts: 2,807
Trader Rating: 96 (100%+)
Default

Quote:
Originally Posted by kiwipete View Post
Power lab 8 & TP lipos work for me.
what power supply are you using?
LOW ET is offline   Reply With Quote
Old 05-02-2013, 04:02 PM   #289
Tech Addict
 
Join Date: Apr 2011
Posts: 633
Trader Rating: 59 (100%+)
Default

I prefer this supply...
http://www.ebay.com/itm/200915041244...84.m1586.l2649
MC112b is online now   Reply With Quote
Old 05-02-2013, 04:04 PM   #290
Tech Master
 
eds24's Avatar
 
Join Date: Apr 2005
Location: Colorado
Posts: 1,128
Trader Rating: 56 (100%+)
Send a message via AIM to eds24 Send a message via Yahoo to eds24
Default

Here is a helpful calculator to help you figure out if your powersupply will be powerful enough for any charger.

http://www.revolectrix.com/pl6_calcu...PL6_Calc_1.htm

Last edited by eds24; 05-02-2013 at 04:55 PM.
eds24 is offline   Reply With Quote
Old 05-02-2013, 04:19 PM   #291
Tech Champion
 
robk's Avatar
 
Join Date: Aug 2001
Location: Macho Business Donkey Wrestler
Posts: 7,567
Trader Rating: 22 (100%+)
Default

Quote:
Originally Posted by DesertRat View Post
amperage ratings are for wire in a wall without cooling airflow. In a car, cooling air can and will greatly increase the useful max sustained amps the wire can support. Think about it, a 3.5 turn motor on 2s will draw 100 amps briefly to make its max 750 watts of power, but the cooling occurs for the whole run. Ratings for wire are BS for our application.
I guess that's why I see 1/12 guys unsolder motor wires during a run on occasion....lol.

The 476 A would be a sustained discharge, correct? #12 is ok for bursts of 100A but you are not going to flow those amps over 5-6 minutes at a constant rate. The battery would unsolder its internals.
__________________
A mutually re-enforcing cascade of failure

"Failior [sic] crowns enterprise." Robert Goddard

I-Lap Scoring Systems http://www.rclapcounter.com/
robk is offline   Reply With Quote
Old 05-02-2013, 05:37 PM   #292
Tech Initiate
 
kiwipete's Avatar
 
Join Date: Feb 2012
Location: Perth WA
Posts: 35
Default

Quote:
Originally Posted by LOW ET View Post
what power supply are you using?
This one below (maxamps)
This 24v power supply is a beast! It can handle multiple high end chargers at one time with up to 1150 watts! If you need the best rc power supply for all those amp hungry chargers, pick up this MaxAmps.com 24v to supply all your power needs.
•100v-240v AC Input Voltage
•24.3v DC Output Voltage
•47A Continuous Output Current
•1150W Output
•11" x 4.5" x 3.125" dimensions
•6.5 lbs
•Short circuit and over-voltage protection
•Heavy duty metal cabinet
•1-year guarantee

This powerful and easy to use power supply will work perfectly with the Cellpro PowerLab 8 Charger and all Hyperion DC Chargers requiring a heavy-duty power source.

Note: This power supply comes with two power cords. Both need to be used to achieve 24V. In addition, you have the flexibility of using it as a 12v power supply by only powering the negative(black) side of the unit.
__________________
67 Vette (VTA)
F104W-GP (F1)
kiwipete is offline   Reply With Quote
Old 05-02-2013, 06:55 PM   #293
Tech Addict
 
Team Grid RC's Avatar
 
Join Date: Sep 2010
Posts: 631
Trader Rating: 3 (100%+)
Default

Quote:
Originally Posted by robk View Post
I guess that's why I see 1/12 guys unsolder motor wires during a run on occasion....lol.

The 476 A would be a sustained discharge, correct? #12 is ok for bursts of 100A but you are not going to flow those amps over 5-6 minutes at a constant rate. The battery would unsolder its internals.
There is no reason that the 1/12 cars don't run 2S with a lower KV motor to draw less amperage. Less wear and tear on the battery, ESC and motor.
__________________
www.GridRC.com
Team Grid RC is offline   Reply With Quote
Old 05-03-2013, 02:46 AM   #294
Tech Addict
 
Join Date: Apr 2011
Posts: 633
Trader Rating: 59 (100%+)
Default

Before anyone spends the money on a 24v supply, you should do some simple math to see what your requirements really are. Anyone running a 1, 2, or 3s battery really doesnt need a 24v supply. I thought i needed a 24v when i got my Powelab8, realized how to math it out and was amazed how few of watts even 30 amp charge rates were at lower voltage batteries. The charger wont do anything different at 24v . GET OVER IT AND SAVE YOUR MONEY UNLESS YOUR INTO 4S OR ABOVE BATTERIES.
MC112b is online now   Reply With Quote
Old 05-03-2013, 04:45 AM   #295
Tech Addict
 
Team Grid RC's Avatar
 
Join Date: Sep 2010
Posts: 631
Trader Rating: 3 (100%+)
Default

Quote:
Originally Posted by MC112b View Post
Before anyone spends the money on a 24v supply, you should do some simple math to see what your requirements really are. Anyone running a 1, 2, or 3s battery really doesnt need a 24v supply. I thought i needed a 24v when i got my Powelab8, realized how to math it out and was amazed how few of watts even 30 amp charge rates were at lower voltage batteries. The charger wont do anything different at 24v . GET OVER IT AND SAVE YOUR MONEY UNLESS YOUR INTO 4S OR ABOVE BATTERIES.
A PL8 is overkill for 3S. The PL6 would have been more than enough.
__________________
www.GridRC.com
Team Grid RC is offline   Reply With Quote
Old 05-03-2013, 05:11 AM   #296
Tech Champion
 
robk's Avatar
 
Join Date: Aug 2001
Location: Macho Business Donkey Wrestler
Posts: 7,567
Trader Rating: 22 (100%+)
Default

Quote:
Originally Posted by Team Grid RC View Post
There is no reason that the 1/12 cars don't run 2S with a lower KV motor to draw less amperage. Less wear and tear on the battery, ESC and motor.
No reason except that all the spec classes would have to change, and all the car designs.
__________________
A mutually re-enforcing cascade of failure

"Failior [sic] crowns enterprise." Robert Goddard

I-Lap Scoring Systems http://www.rclapcounter.com/
robk is offline   Reply With Quote
Old 05-03-2013, 05:35 AM   #297
Tech Addict
 
Team Grid RC's Avatar
 
Join Date: Sep 2010
Posts: 631
Trader Rating: 3 (100%+)
Default

Quote:
Originally Posted by robk View Post
No reason except that all the spec classes would have to change, and all the car designs.
I am sure it will evolve to that like everything. It did when it evolved to 1S Lipo from 4 cell NiCd/NiMH
__________________
www.GridRC.com

Last edited by Team Grid RC; 05-03-2013 at 06:01 AM.
Team Grid RC is offline   Reply With Quote
Old 05-03-2013, 06:01 AM   #298
avs
Tech Master
 
avs's Avatar
 
Join Date: Jul 2006
Posts: 1,175
Trader Rating: 2 (100%+)
Default

Quote:
Originally Posted by Team Grid RC View Post
I am sure it will evolve to that like everything it did when it evolved to Lipo from NiCd/NiMH
if you want to talk about evolution, how about we evolve to a battery that won't catch on fire! it is tough to understand the stampede past LiFe-Po4 to LiPo when one considers the hazard vs performance trade offs.
__________________
Tony Shimko
avs is offline   Reply With Quote
Old 05-03-2013, 06:20 AM   #299
Tech Champion
 
AdrianM's Avatar
 
Join Date: Aug 2001
Location: Tampa, FL
Posts: 5,914
Trader Rating: 4 (100%+)
Default

Quote:
Originally Posted by Team Grid RC View Post
There is no reason that the 1/12 cars don't run 2S with a lower KV motor to draw less amperage. Less wear and tear on the battery, ESC and motor.
I can't imagine any regular 1/12th or WGT racer suggesting such a thing. 4 cell 1/12 was better than 6 cell and took over. Lipo cars now are better handling and faster than the 4 cell cars were and no serious pan car racer would want to go back.

We have proven over an over that running less voltage in our systems results in cooler electronics, improved durability and better racing. There are no overheating/run time or durability issue at all in 1s racing. In our application, with our current motors, lower voltage results in lower wattage and lower temps. Increased gearing and timing will not let our motors put out the same wattage at a lower voltage as they do at a higher voltage. 10 years ago there was a huge argument going on here between me and a user called Kufman. He is an EE Phd, I am not. Eventually Mike Reedy himself came on here and said I was right and her was wrong about this. There is more going on in our systems than can be explained with the simple V=IR, Ohm's law equation.

If someone unsoldered motor wires running 1s they are clueless. They had to have been running open mod with 20g wires overgeared with boost or something. I race on a high grip carpet track with some very fast guys. The hottest I have ever run a motor was 175 deg F when I ran too much gear and timing. I have seen motors hit 200 deg F when a guy over geared, commented how terrible the motor was running and continued to run 6-7 minutes anyways...once again the guy was an idiot.

Second, 1s batteries last forever in 17.5 and and 13.5. In a perfect 8 minute 13.5 1/12th run I think I use ~3000mah out of my 6500 packs. That's around 20-25A average over 8 min. That is not tough on modern batteries. Mod is brutal whether you run 1s or 2s. Mod racers can degrade a couple packs in a season.

If you look at the pros and cons 2s pan car racing does not make sense. Right now racers can use the same 17.5, 13.5 and Mod motors in any 1s or 2s car. The only special gear they need to run 1/12 or WGT are 1s cells and an rx pack, or booster, or 1s speedo.
__________________
Adrian Martinez
What I run: Schumacher Mi5/Associated RC10R5.1/Associated RC12R5.2/Futaba/HobbyWing/Team EA Motorsports/BSR Racing
Where I run: Florida Indoor R/C Complex/Thunder Racing/Florida On Road State Series
AdrianM is offline   Reply With Quote
Old 05-03-2013, 06:25 AM   #300
Tech Addict
 
Team Grid RC's Avatar
 
Join Date: Sep 2010
Posts: 631
Trader Rating: 3 (100%+)
Default

Quote:
Originally Posted by avs View Post
if you want to talk about evolution, how about we evolve to a battery that won't catch on fire! it is tough to understand the stampede past LiFe-Po4 to LiPo when one considers the hazard vs performance trade offs.
If NiCad and NiMH provided enough energy, then Lithium would not have been developed. Lithium packs more energy in a smaller weight, but because of the chemistry, it has it safety issues. Over time, the chemistry will change to safer versions.

In the meantime, proper handling of Lipo will still yield greater performance over the old days of NiCad and NiMH. As for LiFe-Po4 being used for rc racing, it is up the the market to adopt it instead of Lipo.
__________________
www.GridRC.com
Team Grid RC is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 12:23 PM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net