wagen017

This is my first year that I am going into winter with a 2m F3A electric plane. I have the impression temperatures have their effect on my lipo batteries, the internal resistance when measured cold (5 degree C, 40? F) is significantly higher then after a flight.

I would like to hear opinions about electric flight during the winter. Is it better to store lipo's and fly fuel during the winter or does it not really matter? Is there a reduction in power? I am flying a Pletty setup.

Any recommendations on storing lipos? There is a storage program on my charger which I can use. Will that take care of things? I store my lipo's in the garage where it gets cold but doesn't freeze.

Volkert

can773

My Feedback: (1)

Avoid flying in temperatures less than 10C-15C with an F3A electric model without taking precautions. If you do fly in temps lower its wise to preheat (to 40C+) your packs and reduce, or eliminate any cooling air so the packs will stay warm during the flight. An eagletree logger with a temp probe helps to identify how warm your packs are staying during flight, and then you can adjust things based on that knowledge. You can very easily over discharge packs while flying in cold weather. As long as you can keep the packs warm, you will not see any reduced performance, except maybe your own flying because your fingers are frozen!

For storage, discharge to about 3.8 V/cell and keep cool around 5C (I keep mine the refrigerator), then do a new break in (low power for 5-10 cycles) in the spring to bring them back to best performance.

wagen017

Thanks Chad for your comments. Could you comment on the break in? I haven't heard about that. Would it be like flying max. 3/4 of throttle or something similar?

If you wouldn't have a proper way of pre-heating your packs, would it be OK to do a short flight (4 minutes?) first with each pack to get them warmed up? Is the main concern too much discharging?

Volkert

can773

My Feedback: (1)

Hi Volkert

Yes break in is essentially going easy on the pack for the first few cycles, reducing the depth of discharge and peak amps. The easy way is to prop down or to just fly and practice rolls and such things for a bit

My experience is that packs mainly heat up from discharge, so by flying a short flight you wont make them very hot. Presumably if you fly in the winter you have a car nearby! The easiest way is to run your car and use the heater to warm up the batteries.

I feel that its important to get them hot prior to the flight for best performance.

Anthony-RCU

My Feedback: (2)

Hi Chad, missed you at the Nats this year.
One thing I plan on trying is a reusable heat pack from the drug store. Have to double check the specs but it heats up to 130°F for around 30 minutes. Then boil in water when you get home to reuse. Around $15 bucks. Has anyone tried one?

serious power

Hi,
One of our guys is using 12v baby bottle warmers. Work very well.
The temp is good and suit must batts.
Just google ' 12v bottle warmer'

Brian

can773

My Feedback: (1)

Hi Anthony,

I have never tried it, but I know some of the F5D (electric pylon) were using something like that to get their packs hot before flights. Since our packs are so big though I would try to heat them evenly so the inner cells get warm as well. Maybe a couple of those or Brian's idea of bottle warmers in a small insulated cooler would work well

I just leave my car running, I figure we need some global warming in this part of the world anyway so a little greenhouse gas is a good thing LOL

Steve

My Feedback: (54)

I've used those hand warmer packs in the winter time, but only inside my transmitter glove. They work great for keeping your hands warm, so I think they would also work for the batteries. I too am going with an electric for the first time this winter season and hope the electric is going to be much easier than the gassers in temps around freezing.