RCThunder

Any many tracks are starting to limit the battery temps before racing? Just curious? 10 degrees over ambient is working for some places....

danjoy25

iTrader: (38)

I would only consider heating if my driving is 95%-100% all the time as its pretty useless if you keep on cliping domes.

HenBeav

iTrader: (13)

heat it to 110 to 130F, any more than 130 doesn't seem to help

EAMotorsports

iTrader: (79)

110 seems to be the going thing now. It allows a little better performance to compete with NIMH but is no where near the danger point of a lipo. Ambient temp is a little more difficult to me. Outside Orlando on a table in the sun = big problem!! Ambient temp allows some variables. 110 degrees does not.

EA

SWTour

iTrader: (9)

INDOORS may be easier to monitor than outdoors for this. MFG's generally tell you a heated battery will perform better, and to NEVER run a LIPO COLD. (See MFG. warnings for min. temp.)

The mentioned 110 - 130 seems about right - that's what several of our racers have been doing. I don't like it personally, but it's very hard to police (as I said...outdoors) and since we only run 3 races a year indoors I won't impose a rule there either.

I think our guys did a GREAT JOB with saftey this year - and we've now been 100% lipo since DECEMBER '07.

I support HEATING more than I support LIPO SACKS. (IMHO Liposacks HIDE the battery, and don't allow you to see it if it gets OVERCHARGED or has an issue until it's WAY too late.)

For warming, we have guys using heating pads (inexpensive from Wal-Mart) that seem to put the battery in the perfect temp range. Others are using reptile heating pads, or boxes with an air vent and a lightbulb to create the heat... (Like an EASY BAKE OVEN)

Personally, I noticed about an average voltage increase of .3 - .4 volts through virtually an entire 5 minute run. (Using the EAGLETREE E-Logger)

ntc3racing

How you guys are heating up you lipos?

Adam?

Most guys use some kind of heating pad, like the kind for a sore back. They're $10 at Walgreens. If you go to the pet store, you can buy a smaller one that stick to the bottom of an aquarium to keep snakes warm, wrap the battery up inside of it like a burrito, and stick it in your Liposack. Keep an eye on the temps and how long you warm it though, I've seen some SMC's swell up.

My snake, it's so warm...

lauri

iTrader: (2)

I know it works... I've done off track and on track testing. I've only ran two races with heated LiPo but the effect can be seen and felt.

I could only measure the voltages with 5A discharge and even then the difference was more than .1V. The bigger the discharge current the bigger the voltage difference by temperature imho.

I have heated it with a hairdryer a plastic bottle is taped to the hairdryer and the battery sits inside it. I have 2200W dryer and its temp settings are just perfect!

Probably an electric "heating-sack" is more convenient.

I'm also considering to build a heat isolation for the battery when its on the car. Stock-motors don't consume enough amperage from a 5Ah battery to keep the it warm. It actually cools down during the 5-minute race...

I consider 50Celsius or 120Fahrenheit the optimum non-dangerous temperature for the LiPo to keep at.

shadow102

iTrader: (21)

A couple of us are experimenting with heating the lipo's at our local track. Being one of the back of thepack guys I can still feel a difference the pack is punchier and faster over the entire run. I haven't seen the heat pad method yet but two of us have the $8 desk lamps from walmart that use the 40w bulb and just heat the pack with that. Although the perfect solution is MuchMore racing sells a battery warming tray for I think about $35

Lazer Guy

iTrader: (1)

Question
I'm not looking to get the most volt's out of my new TP 4900's I just want them to last as long as possible.
Last winter I checked the temp when I got to the track.
My old lipo's were 65*, after charging they were 70*, after 10 min. practicing they were 90* running with MM 4600kv in 10.5 class.
This year I've been using 12+ hour Mega warmer's(you get 10 for $10) I put one in my box when I leave the house, when I get to the track my lipo's are 90*, I keep them at 90* all day long.

Does this sound like the best way to get the most life out of my lipo's ???? or am I over babying them ???
Thanks Guys

Adam?

I've got the tray, and it's pretty mediocre to be honest. Also, since most people put weights on their packs somewhere, they almost never fit in the tray.

CarbonJoe

Also why you don't want to store them inside your car in the midday sun.

ottoman

iTrader: (13)

Yea that MIGHT get them above 32 degrees around here during the winter season

Dragonfire

iTrader: (1)

I have tested heated and cold lipos and you get around 0.3v average difference at 20amps. I use a back warmer as they have adjustable temp. Just get some form of contact thermometer to work out what you need (mine works great at 6) you are set to go. Just chuck it in after its charged.