View Full Version : warming up lipo????
newbie2 02-14-2009, 01:18 PM I see trinity is now selling a lipo battery warmer....this warms the battey to constant 140 deg.....there saying this lowers the resistance, and allows for more voltage.... they do this before charging and using the pack for a race. Anyone have any imput on this??....IO know my batterys never get warm when charging and after a race they are seldom warm....
DOUGHBOY 02-14-2009, 02:33 PM Buy It They Work.... You Can Do A Simple Test At Home... Use A Turbo 35gfx And Cycle Your Battery With It At Room Temp And Write Down All Your Info Then Wrap Your Battery Up In A Heating Pad For About 15 Minutes Which Should Take It Up To About 120 Degrees And The Cycle It Again While Its Still Wrapped Up In The Heating Pad And You Will See A Pretty Big Difference In Numbers.... Mainly Internal Resistance And Your Avg. Voltage...
hankster 02-14-2009, 02:43 PM http://www.hobbytalk.com/bbs1/showthread.php?t=243961
nutz4rc 02-14-2009, 03:20 PM Remember how excited we were when Lipos appeared and we thought "no more battery wars", no stupid tricks that can cause injury, some sanity in battery applications. NOT
We are now seeing Lipos climb from 15C to 40C and heating them up to increase performance.
We are going to see a real tragedy sooner or later and then what?
Take a look at the video from Snowbirds when a can of motor freeze is being sprayed on a car in the pits while a battery change is being made. An arc and then explosion of can in the face of the pit crew.
Keep it up and we will see a race facility burned to the ground or someone really hurt severely.
hankster 02-14-2009, 03:27 PM Or we could run exploding NiMh cells that only last a few months :)
nitro4294 02-14-2009, 04:04 PM Or we could run exploding NiMh cells that only last a few months :)
That's funny, I have NEVER had a NiMH cell explode. Is this a normal thing or am I doing something wrong???:confused:
nutz4rc 02-14-2009, 04:46 PM At the tracks I run at, I have seen three NIMH packs explode. One racer had acid in his eyes fortunately they got it washed out before any permanent damage. Second blow up tossed a piece of burning batt on the carpet track and burned a hole. The third one I saw a piece of the metal batt shell just missed hitting a buy in the head and it stuck in the dry wall behind him. None of these batts was being overcharged or mistreated.
One racer had a Lipo swell after he set his charger for NIMH by mistake. Fortunatley no explosion or fire.
LIPOs are safer (IMO) but anyone can do something that takes away the safety of any item. I think heating a batt is asking for trouble again IMO.
jmccormick 02-14-2009, 05:25 PM like I keep saying why?????
If nobody did it no issue period...
Its time for race directors promoters etc to grow some kahona's and not allow it. Even if certain racers have a hissy fit because they cant have that little extra voltage.
All it is going to take is 1 tragety related to overheating a lipo and then watch what happens. No tracks will be running because insurance rates will be way to high for them to continue.
Fortunately we do have a safe gaurd to help minimize the damage from a lipo fire but as hard as it is for me to believe there are still tracks and even guys that charge at home without them.
Exploding cells where a manufacturere issue and yes we where lucky and I can go on and on how wrong it was for the cell manufacturere to accept it.
Lipo's IMO are very safe until you start doing things with them like overcharging and overheating THIS IS ENTIRELY AN ISSUE CAUSED BY THE USER and can be avoided completely by not allowing it.
The motor freeze is just as bad with lipos.Tracks should baned that also.
newbie2 02-15-2009, 08:28 AM I don't plan on doing it, I just happen to see it advertised in RC CAR magazine an wondered if it worked. I can see the problems being created by hot batterys whether it be nimh's or lipo's... I actually heard something say last night at a capret race they wre banned especially indoors..
C43GO 02-15-2009, 08:55 AM all I can say is go to a BRL event and watch some of the best racers around they don't and CAN't heat them per the rules and theses guys are faster than most buy not using this trick.
Diff Dude 02-15-2009, 11:19 AM Nutz4rc,
Heating the lipo battery had NOTHING to do with the ball of fire during the induro race.
Dave
Nutz4rc,
Heating the lipo battery had NOTHING to do with the ball of fire during the induro race.
Dave
It was from motor freeze and from spark when pluging in or unpluging lipo pack.
Thats a new way of heating packs LOL
King Dork 02-15-2009, 01:26 PM Back in the NiMH days (ha ha!) our local racers (club level) always advised people to charge their packs at a minimum 2C rate. I always charged mine religiously at a 1C rate. I know higher c rate gives more voltage, but less run time and less overall cycles. I could never see any performance difference at our track, but I did notice that they replaced all of their's at least once over the summer. Mine ran strong and pulled almost identical numbers (IR, voltage, runtime, etc) all summer. I upgraded to lipo and gave my matched packs and Novak SE tray to a young fellow racer who's a great kid. He ran them the following summer and they still performed great. Same goes for the lipos now. Most of our locals charge theirs at a 2C rating and I still charge mine at a 1C. Still, can't see any difference on the track and my Peak 4800 lipo has run 2 full summers (never balanced first summer and only occasionally last summer), and I'll run it again this summer. Some racers feel the need to get any edge (real or fantasy) they can, regardless on the negative effects it will have on their fellow racer's opinions or safety and lifespan of their equipment. Concentrating on getting your car around the track will make you faster in the long run than any "hot trick". Unfortunately, in the end, the manufacturers only seem to care about getting that half step ahead of the rest. At least we can controll it on our end. Let's just race:thumbsup:.
nitro4294 02-15-2009, 01:56 PM For the last 5 years, I have purchased my nimh packs from one guy and he recamended charging them at 5 or no more than 6 amps, discharge at 30 amps. I have followed that and, like i have stated all along, have not had a cell even vent, let alone exlpode.
Also, I run practice batteries that are sometimes 2 to 3 YEARS old. They will not work in a big race, but at the club level, they are just fine.
So now that I have lipos, from the same supplier, I follow his recamendations and have not had a problem so far.(no more than s 2c charge and DO NOT HEAT)
I know accidents are going to happen and things can go wrong, but if a person keeps his head screwed on right and pays attension, this kind of stuff shouldn't happen.
I refuse to heat my lipos simply because if i need a tenth or two one the track, I work on the car to get it to handle better and if that don't work, so be it.
My two cents, Thank you.:wave:
King Dork 02-15-2009, 06:46 PM Well said nitro4294:thumbsup:. Too many people are looking for the "magic elixer" to make them faster on the track. I was a dirt oval guy who converted to offroad only a few years ago. My strength on the track is my patience. I rarely lose my cool and only "race myself". I try each week to improve on my previous times and each week will only find one or two spots on the track and try to improve on them. Must be doing something right since even though I'm not the fastest guy on the track in all the classes I race in, I'm right there with them. Too many people have tried to tell me, "if you do this or that with your batteries, you'll be faster." My secrets to improving are, stay calm no matter what, keep your equipment cleaned and maintained between race weeks, only care about what YOU'RE doing on the track.
Minreg 02-18-2009, 01:27 AM ditto ditto...
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