R/C Tech Forums

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

Thread Tools Search this Thread
Old 07-01-2010, 04:16 PM   #46
Tech Elite
Join Date: Nov 2007
Posts: 3,203

Originally Posted by linger View Post
Stating that the main and only reason that Lipos puff from RC CAR applications is from the amperage demands is completely off target.

Stick a data logger on any RC car. Peak loads during max acceleration from a highly boosted 13.5 motor is a hair over 50 amps. This is a peak current and is never sustained. Average current over a 6 minute run is about 25 amps. For 17.5, the amp draws are much lower.

This is well under the capability of just about EVERY hard cased lipo, even those with inflated C rates. Even a 15C lipo will easily handle this current range.

Running a lipo over it's usable current results in very high temps. Over 180 deg and the electrolyte starts to break down and forms gas. Temp a lipo after run and it's nowhere near this temperature.

So what causes a lipo to puff?

Lot's of reasons and each has it's own specific failure modes. Here is a list - mostly likely incomplete.
  • Immature Formation Process:
  • Insufficient Hi-Pot testing during the electrode stacking process
  • Insuficient or non-existant incoming material inspection
  • Insufficient contaminant filtering of the slurry raw materials
  • Bad pouch seal or badly designed pouch seal
  • Overcharge
  • Overdischarge
  • Overcurrent
  • Overtemp

My guess on why a bunch of lipos are puffing is due to the immature formation process. This process is highly proprietary to each manufacturer. This can take anywhere from 4 days to 2+ weeks depending on manufacturer. This process takes years to master. A lot of these lipo companies are very new and their formation process is immature. Combine this with a new untested chemistries and you have long term issues.

Sorry, for this tangent to a thread titled "Intellect 50C thread"
Dont be sorry this is very good information and keep it coming not all of us know everything and it is great to learn from different people so your opinion and advice means alot ot me and many others on the thread .

6 months ago i had mentioned contamination in another thread and man im so glad you brought it up as back then i was in a factory where they were mixing raw materials in a bucket and yes in a bucket in an uncontrolled environment and they were applying the electrolyte on the copper sheets with a paint brush in an open area with dust etc .I also saw a switch during producion from one chemistry being lipo to lifep04 within the same machine without being cleaned .I also saw air bubbles in the seal not just one but many small air bubbles .

so yes contamination is a large problem as is quality control .My info comes from extensive testing that we do week in week out and yes some puff and some dont with the same testing procedure.

keep the info coming and i sure we will come to a conclusion
Email : teamcobraracing@gmail.com or ae@hobbywing.com
Repair service Address
Hobbywing Technology Co., Ltd.
4th Floor, 3rd Building, KeLunTe Industrial Park, ShangLiLang, BuLan Road, LongGang District, ShenZhen, China
COBRARACING is offline   Reply With Quote
Old 10-06-2010, 05:14 AM   #47
Tech Adept
whobedat's Avatar
Join Date: Aug 2010
Location: Brisbane
Posts: 168
Trader Rating: 11 (100%+)

Just got two of these batteries today. Fingers crossed that they last a little longer than 20 cycles!
Schumacher CAT SX/SX2
Schumacher Cougar SV
Tekin RS/RS Pro
Tekin Redline 10.5/17.5
Futaba 3PKS
whobedat is offline   Reply With Quote

Similar Threads
Thread Thread Starter Forum Replies Last Post
The Speed Passion Thread memix Electric On-Road 13131 09-20-2016 06:59 AM
RRCSA Electric Racing at Littlehampton, South Australia Swanny Australian Racing 1229 10-01-2011 05:44 AM
*** Intellect 5600 50C 7.4V Li-Po Battery Pack *** raydog R/C Items: For Sale/Trade 7 04-01-2010 09:53 AM
Intellect Battery 3800 rayhuang Electric On-Road 1166 05-30-2006 06:51 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 01:45 PM.

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

SEO by vBSEO 3.5.0