R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 08-31-2014, 07:57 PM   #1
Tech Master
 
Join Date: Jun 2004
Location: SoCal
Posts: 1,099
Trader Rating: 6 (100%+)
Default 12 Month old Lipos still competitive?

Ive been running year old cells now and as of late my times have dropped as the races have gone on and I thought it was my car going away(high temp outdoor asphalt) due to tires over heating, but I've given some thought about power delivery. I bought these cells a month before last years IIC and seem to put out some decent lap times but can't keep hold the same times for 5 min.

So i will ask the consensus, Do you think my cells are no longer competitive?

PS. the cells in question are Aeromodel 7200, and Ip 7200 with 5mm plugs.

Thanks for looking.
__________________
Minh Nguyen
[Maclan Racing] [Xpert Servos]
trigger is offline   Reply With Quote
Old 08-31-2014, 08:01 PM   #2
Tech Elite
 
LasagnaCat's Avatar
 
Join Date: Oct 2001
Location: Hickory Hills, IL
Posts: 2,085
Trader Rating: 143 (100%+)
Send a message via AIM to LasagnaCat
Default

Do you have (or have access to) a charger that gives you the packs IR reading?
__________________
Well if it seems to be real, it's illusion
For every moment of truth, there's confusion in life...
LasagnaCat is offline   Reply With Quote
Old 08-31-2014, 08:11 PM   #3
Tech Master
 
Join Date: Jun 2004
Location: SoCal
Posts: 1,099
Trader Rating: 6 (100%+)
Default

I don't have one of the modern Icharger but i think my Hyperion 720 super duo does. do i check as its charging or discharging and what numbers should i be looking for? I know the values are different from charger to charger.
__________________
Minh Nguyen
[Maclan Racing] [Xpert Servos]
trigger is offline   Reply With Quote
Old 08-31-2014, 10:01 PM   #4
Tech Master
 
Join Date: Jun 2004
Location: SoCal
Posts: 1,099
Trader Rating: 6 (100%+)
Default

After a little bit of time spent cycling some some cells and I'm getting numbers like 12-15 ohms across the pack and 3-4ohm per cell. Im guessing those numbers are on the high side meaning too much resistance?
__________________
Minh Nguyen
[Maclan Racing] [Xpert Servos]
trigger is offline   Reply With Quote
Old 09-01-2014, 02:34 AM   #5
Tech Elite
 
Skiddins's Avatar
 
Join Date: Feb 2006
Location: Windsor, UK
Posts: 4,761
Default

Quote:
Originally Posted by trigger View Post
After a little bit of time spent cycling some some cells and I'm getting numbers like 12-15 ohms across the pack and 3-4ohm per cell. Im guessing those numbers are on the high side meaning too much resistance?
Provided those figures are accurate they're not too bad, I've raced with worse.
If you really think they are an issue, you could try buying just one new pack of cells and see how they compare, that will confirm it.

Skiddins
__________________
Xray T4'18, T4'14 (Wet Car)
Xray X12 2018
Xray X1'16
wlrc.co.uk (West London Racing Centre)
RCDisco.co.uk
Skiddins is offline   Reply With Quote
Old 09-01-2014, 03:25 AM   #6
Tech Fanatic
 
Salkin's Avatar
 
Join Date: Jan 2014
Posts: 882
Default

If you want to try some "cheap" Hobbyking lipos, try these:

https://www.hobbyking.com/hobbyking/...dProduct=64930

I have had great luck with all my previous Turnigy nano tech lipos, and these are the latest "high-end" lipos from HK with great specs and price.

I have just bought two of these, and have high hopes for them
__________________
Yokomo BD7 2016 Black Series - MuchMore Fleta Pro / MuchMore ZX - Highest DLP650 - Sanwa M12
Salkin is offline   Reply With Quote
Old 09-01-2014, 03:49 AM   #7
Tech Elite
 
Bishop's Avatar
 
Join Date: May 2004
Location: Brisbane
Posts: 2,223
Trader Rating: 5 (100%+)
Default

Use and storage is key, packs used often and stored well can be fine 12 months later, not used much and stored too long or not properly and they will be shagged in 6 months.

Although, not all packs are equal, but many are good now.
__________________
QRCCRA
www.qrccra.org.au
www.facebook.com/englandparkraceway
www.myrcm.ch/main?pLa=en&hId[1]=org&dId[O]=4331
Bishop is offline   Reply With Quote
Old 09-01-2014, 08:30 AM   #8
Tech Master
 
Join Date: Jun 2004
Location: SoCal
Posts: 1,099
Trader Rating: 6 (100%+)
Default

Storage and puffing isn't a problem as i do store my cells at 3.7ish. I do believe my current packs are decent but when on the track among really strong competition, these packs show their weakness when compare to newer cells. I have order two new packs and will log their performance and resistance.
__________________
Minh Nguyen
[Maclan Racing] [Xpert Servos]
trigger 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 10:13 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net