Batteries and heat

[LEM]

I am curious/concerned about the current heat wave (115 in Las Vegas yesterday) and the effects on batteries. Obviously, don't leave them in your car or sitting in the sun. But, what about when flying?

I fly and electric heli (Axe CP) and have cut some vent holes in the canopy. However, even on cool days the battery and motor get pretty warm at the end of my hovering attempts as the battery gets low. I am currently flying only the NiMH (?) that were included.

Is there a concern about the batteries getting too hot when used in the extreme heat? Can this cause fire? What about LiPo's I know they tend to be a little more volatile?

Sure would hate to have my heli burst into flames just as I get a solid hover going.

What about the motor? Is the heat sink adequate?

Thanks

[vapochilled]

Any current carrying/using device will rise X above ambient.

The higher the ambient, the quicker the rise, that said, if a product is rated at say 170 degrees, and you start at 50, you have more headroom than say starting at 115!
So yes, it is a concern, and one you are right to think about. I tend to avoid flying in the heat of the day, aim for morning or late afternoon flying. It's more comfortable to you as well,lol
few people monitor their system temps, but it would not hurt to get a thermometer and check whats what with your motor and cells, leave a longer cool down between flights and try and keep the whole shabang out of the sun when not flying.

[LEM]

Thanks Vapochilled

That's pretty much what I was thinking. I just had a couple good flights (a relative term since I am still working on hovering so "good" means no crashes and flight means 1-36 inches off the ground) in about 97 degree temps. With about 1/2 hour in the A/C in between.

I have heard nasty stories about overheated LiPo cells. So I think I'll hold off on buying/using them until the ambient temp comes down a bit. That way I'll have a better safety buffer.