billdelong

iTrader: (33)

please explain... if you think the silicone will fail and the battery may come loose, then I will squash that theory because most brands of silicone are rated for 200 PSI shear strength.

gigaplex

iTrader: (2)

If it's really that strong, you may damage the chassis or battery removing it. Or maybe the battery could be damaged in an accident and can't be quickly removed to put in a sand bucket. And it's unlikely you'll be charging in a lipo bag if the battery is glued to the chassis.

mrreet2001

iTrader: (9)

This /\/\

billdelong

iTrader: (33)

This is a fair argument for textbook safety, but in reality of the dozen or so states I've raced, I've never once come across a track that requires LiPo bags and I might see maybe 1 / 100 of racers actually use a LiPo bag and at least 50% (or more) will charge their batteries in their cars. Of the LiPo fires I've personally witnessed (4 over the course of the past 12+ years), in every case it was caused by operator error with a racer attempting to over charge their LiPo in NiMh mode and forgetting to monitor the voltage and walked away. Most of the time these LiPo fires occurred with the LiPo mounted in the chassis and minimal damage occurred to each respective car. One guy was able to slap in a new battery and raced immediately the next round after his LiPo fire which only left burn marks on the chassis. Other guys were not as fortunate and had to replace a few parts ranging from melted battery trays, center diffs, etc..not a single LiPo fire created a total loss of the chassis of the fires I have witnessed in the pit room. Grabbing a car is a lot safer/easier than having to kick a burning battery out of the pit room, been there done that, ha!


At the end of the day it comes down to taking proper care of your batteries, ONLY use LiPo mode and monitor the IR of your cells after every charge to know when it's time to replace an aged battery and you will do fine.


I did see a guy remove siliconed battery a couple weeks back using a hobby knife and yes, he scratched the heck out of his chassis, but all the scratches were hidden after he re-mounted a fresh battery.


It's certainly not my preference, but I see this practice often enough to where I feel it's warranted to be shared as a viable option.

Roelof

Yeah...right.....

The story of taking good care of your batteries will not help to prevent exploding batteries. I know some people who dare to say that the user did something wrong when the battery did explode where I can be sure the user did not do anything wrong. The LiPo battery is just well known for the unstable chemistry.
That is why in Europe the EFRA made a rule that basically all (Also NiMh) batteries have to be charged in a bag, the simple reason is that any control does not have to look if it is a LiPo or not as receiver batteries still mounted in a car can not been seen.. Also our national organisation and the house rules of most clubs say to use a LiPo bag. It is not about nothing goes wrong but about preventing a huge damage that one time it will go wrong.

Last month I had a huge argue with a guy who's car went in fire when charging his LiPo receiver battery still mounted in the car exploded and hie with his fellow drivers were drinking in the club house. I just said that that is why the house rules said to use a LiPo bag, that guy wen berserk on me while it was just his own fault burning down his car and even bringing the rest of the pits in danger..

billdelong

iTrader: (33)

I challenge this statement where my definition of monitoring battery health is periodically checking the IR of the cells.


I once had a LiPo fire in my house and talk about a pissed off wife with a stanky chemical smell that lasted several days before it aired out. I had remanufactured a NiMh pack for my cordless drill and converted it to LiPo which worked extremely well for many years, but I became complacent and never checked the IR... Roughly 4 years after the conversion it caught on fire during a charge cycle. I consider this a very aged battery that was not well cared for because I never disassembled to inspect the cells for signs of swelling nor did I check the IR... this failure was 100% operator error due to my personal neglect. Fortunately I had the battery plugged into my drill and I was able to quickly carry the drill outside and then remove the battery from the drill so there was no damage to the drill, just a melted battery pack.


I have since adopted the practice of monitoring the IR and subsequent packs that I've remanufactured have had the IR increase noticeably at around the 2 year mark which is when I discard them and make new ones, not a single LiPo fire since. What concerns me is that there are many power tools and full scale automobiles running LiPo without any way to check the IR on those cells, that to me a bigger risk


NiMh pack before conversion


4S LiPo conversion layout


Cordless Drill after conversion

Chubbum

iTrader: (5)

Wow. People are going at it! I didn’t mean to start a war, I appreciate all the input though.

the rc guy

gluing nixx to chassis is a safety issue dont do it .