R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 10-01-2004, 04:58 AM   #1
Suspended
 
Join Date: Mar 2003
Location: Back That Thang Up!
Posts: 3,468
Trader Rating: 11 (100%+)
Default Test your batteries on your computer.

Has anyone used this product:
http://www.westmountainradio.com/CBA.htm

Seeme like a cheap alternative to testing batteries.
403forbidden is offline   Reply With Quote
Old 10-01-2004, 06:24 AM   #2
Tech Master
 
jaysimpson's Avatar
R/C Tech Charter Subscriber
 
Join Date: Oct 2001
Posts: 1,869
Trader Rating: 9 (100%+)
Send a message via AIM to jaysimpson
Default

There is a review of that product in this months Xtreme R/C mag.
__________________
Kalgard Racing
Banzai Motorsports
ProMatch Racing
A-Train Racing
Warehouse Raceway
jaysimpson is offline   Reply With Quote
Old 10-01-2004, 07:22 AM   #3
Tech Fanatic
 
Chill Will's Avatar
 
Join Date: Oct 2003
Location: The Dirty South
Posts: 804
Default

It's cheaper than buying a $350 charger and doing it.
Chill Will is offline   Reply With Quote
Old 10-01-2004, 07:23 AM   #4
Tech Master
 
jaysimpson's Avatar
R/C Tech Charter Subscriber
 
Join Date: Oct 2001
Posts: 1,869
Trader Rating: 9 (100%+)
Send a message via AIM to jaysimpson
Default

Yup, I know they seemed to like it....although it will not discharge at the rate advertised. It still should give you an idea of the condition of your batteries.
__________________
Kalgard Racing
Banzai Motorsports
ProMatch Racing
A-Train Racing
Warehouse Raceway

Last edited by jaysimpson; 10-01-2004 at 07:47 AM.
jaysimpson is offline   Reply With Quote
Old 10-01-2004, 01:10 PM   #5
Tech Fanatic
 
crimson eagle's Avatar
 
Join Date: Jun 2003
Location: Nor Cal
Posts: 841
Send a message via ICQ to crimson eagle
Default

What's the point of discharging pack information?

It won't tell you what the individual cells are doing, if you want to know any real info other than pack capacity and pack voltage which you can get a pretty good idea about on the track anyway this does not provide it.

If you have a bad cell and need to know which one it is, you haven't learned anything usefull.
crimson eagle is offline   Reply With Quote
Old 10-01-2004, 01:50 PM   #6
Tech Adept
 
Join Date: Jun 2003
Posts: 104
Default


Knowing the discharge curve of ours packs is not bad.
They advertise 40A or 150W, whichever is higher!
So this device will discharge a 7,2V at 20,8A.
gearless is offline   Reply With Quote
Old 10-13-2004, 05:31 PM   #7
Tech Apprentice
 
SteveR's Avatar
 
Join Date: Jun 2004
Location: Corvallis, OR
Posts: 71
Default

You can do the same thing with a $50 dollar volt-meter from radioshack and a light-bulb discharger. The only downside is that the amp draw from the light bulbs aren't constant - but should work for comparing packs.

Radioshack has a few models with the capability to interface with a computer and they include the software.
SteveR is offline   Reply With Quote
Old 10-13-2004, 06:26 PM   #8
Tech Initiate
 
LEracing's Avatar
 
Join Date: Feb 2004
Location: Anderson, IN.
Posts: 30
Default

Steve You are correct, you could use a meter and light bulbs. The bulbs do draw a constant current but as the pack discharges it takes more of a load to keep the amp draw constant. The light bulbs are not totally a bad thing because if you think about it a motor acts exactly like the light bulbs. The motor like the light bulbs has no way of increasing the amp draw as the pack discharges.

Dave
LEracing is offline   Reply With Quote
Old 10-14-2004, 10:22 AM   #9
Tech Elite
 
fatdoggy's Avatar
R/C Tech Charter Subscriber
 
Join Date: Aug 2001
Location: MD USA
Posts: 3,642
Default

Just pic up a 16x9 v5, you can get them cheap. Discharge the pack at 20amps and just write down the voltage at the desired times. I've done it in the past and it works fine, as long as you don't mind staring at the charger for a few minutes. Plus you get charging and cycling options with it.....
fatdoggy is offline   Reply With Quote
Old 10-14-2004, 11:01 AM   #10
Tech Elite
 
kufman's Avatar
 
Join Date: Feb 2004
Location: Elburn, IL
Posts: 3,428
Trader Rating: 6 (100%+)
Default

Looks pretty cool. If I had more of a digital background I would build that into my discharger that I am building. Unfortunately I am not really a programmer either.
__________________
Brushes? We don't need no stinking brushes!!!
kufman is offline   Reply With Quote
Old 10-14-2004, 11:06 AM   #11
Tech Fanatic
 
Chill Will's Avatar
 
Join Date: Oct 2003
Location: The Dirty South
Posts: 804
Default

Quote:
Originally posted by crimson eagle
What's the point of discharging pack information?

It won't tell you what the individual cells are doing, if you want to know any real info other than pack capacity and pack voltage which you can get a pretty good idea about on the track anyway this does not provide it.

If you have a bad cell and need to know which one it is, you haven't learned anything usefull.
You will know which of your packs are the best. You will know the runtime of your packs before you run it so you will know how to gear it..... Need I go on?
Chill Will is offline   Reply With Quote
Old 10-15-2004, 07:39 PM   #12
Tech Addict
 
imjonah's Avatar
 
Join Date: Oct 2003
Location: Colorado
Posts: 704
Default Voltmeter use

Quote:
You can do the same thing with a $50 dollar volt-meter from radioshack and a light-bulb discharger
-Steve R

I do not have a problem measuring voltages with my little digital voltmeter.
But I have not figure a safe way of checking higher amp rates, I think 3 amps would burn out my meter. Is there some trick to measuring higher amp amounts?

I would think almost all the readings you get from an expensive charger, you should be able to do with the average low end Voltmeter.
imjonah is offline   Reply With Quote
Old 10-15-2004, 07:50 PM   #13
Tech Fanatic
 
crimson eagle's Avatar
 
Join Date: Jun 2003
Location: Nor Cal
Posts: 841
Send a message via ICQ to crimson eagle
Default

Chill Will,

This is something you already know. A track is the best place to get an idea of which cells are best. Do they last more than long enough? Do they have good speed for the entire race? Bad packs don't do very well on the track and won't do very well on this device. But you can test the pack on the track without buying any new equipment. Now if you can analyse the data from each cell on a pack which you know is bad, then you can replace it or convert to a 4 cell pack or whatever. This is when you will get info you don't already know.

Dusty
crimson eagle is offline   Reply With Quote
Old 10-15-2004, 07:54 PM   #14
Tech Fanatic
 
crimson eagle's Avatar
 
Join Date: Jun 2003
Location: Nor Cal
Posts: 841
Send a message via ICQ to crimson eagle
Default

Imjonah,

Most meters can go to 10amps. If you want to do more you can buy a shunt off ebay for pretty cheap. A 50amp shunt is more than enough. Just measure the resistance accross the shunt under discharge and convert to amps. This will tell you your discharge amps. You can measure voltage at any discharge rate, you won't hurt the meter.

Dusty.
crimson eagle is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Test Msand R/C Items: For Sale/Trade 0 09-11-2008 05:55 PM
How to test the esc? hybridvigor Rookie Zone 7 05-13-2007 09:34 PM
test Greg Anthony R/C Items: For Sale/Trade 0 02-10-2007 05:47 PM
test Ctrl-Alt-Delete Other Items: For Sale/Trade or Wanted to Buy 4 11-15-2002 08:16 PM
test Ctrl-Alt-Delete Buyer/Seller dispute and Feedback discussion forum 0 11-11-2002 06:10 PM



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 03:35 PM.


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