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Did cold batteries cause this problem? What now?

Joined
May 17, 2019
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Hey all. When I went to insert my battery for my first and only flight, I noticed it was a tad difficult to insert. I did get it to push all the way in and flew for a while.
When I tried to lower my landing gear, only one descended while the other stayed up. I flipped the button again and the lowered one went up about a quarter of the way and stopped. I caught the drone and stopped the motors. I tried to insert the other battery but it was difficult too.
I realized I had kept my setup in my truck for a couple of nights when the temp got to freezing. Did THAT cause the batteries to swell? Will they return to normal? Are they shot? I now have a drone with one gear up and one down with two batteries I am afraid to try to insert. Do you think a new battery fully charged will fix it?
Thanks for any ideas.
Ken....NC
 
Has the swelling gone down in a warm environment (house)? If not, I would not use these batteries because they could swell even more when flying. Then you're stuck!
As far as landing gear issue, turn on your Controller and H, lay the H upside down, then flip you gear switch up and down position. This will put the landing gear in the right position. Do this without propellers attached, and with a non swollen battery
 
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Can you post photos of the batteries? Is the plastic case deformed by cell expansion? I’m curious since I have not seen LiPo batteries exposed to freezing temps for an extended period of time.
 
Can you post photos of the batteries? Is the plastic case deformed by cell expansion? I’m curious since I have not seen LiPo batteries exposed to freezing temps for an extended period of time.
I'll see if I can get photos on here. Best place to buy a battery? I should have known better!
 
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It's a chemical reaction causing the swelling, I've heard of some who put batteries in a very cold environment/ freezer and discussed on this forum, to slow down degradation, once swollen there's no miracle cure to shrink them, it could be just a case of bad luck, the charging/storage regime is important, but it could still happen, we all just give it our best shot.
 
It's a chemical reaction causing the swelling, I've heard of some who put batteries in a very cold environment/ freezer and discussed on this forum, to slow down degradation, once swollen there's no miracle cure to shrink them, it could be just a case of bad luck, the charging/storage regime is important, but it could still happen, we all just give it our best shot.
Where are you buying your batteries?
 
I find the H very susceptible to cold batteries, if left in my Jeep on a cold night I warm them for a couple hours before flight. I find you can't just warm them for 15 minutes until the case is warm; I set them in a box on the floorboard with the heater blowing on them, I find 1-2 hours sufficient to warm them properly. I can get a 15 minute flight with a warm battery on a 40*f day while a cold battery will climb out then immediately warn low battery. On cold days I take off and hover for a minute or two while monitoring voltage, if it drops off rapidly I land immediately. If the batteries are warm enough the voltage will hold and continue to what is usually a long flight. I use both Yuneec and Ultra X batteries.
 
Hey all. When I went to insert my battery for my first and only flight, I noticed it was a tad difficult to insert. I did get it to push all the way in and flew for a while.
When I tried to lower my landing gear, only one descended while the other stayed up. I flipped the button again and the lowered one went up about a quarter of the way and stopped. I caught the drone and stopped the motors. I tried to insert the other battery but it was difficult too.
I realized I had kept my setup in my truck for a couple of nights when the temp got to freezing. Did THAT cause the batteries to swell? Will they return to normal? Are they shot? I now have a drone with one gear up and one down with two batteries I am afraid to try to insert. Do you think a new battery fully charged will fix it?
Thanks for any ideas.
Ken....NC
It's never a good idea to store batteries in freezing temperatures and then fly without warming up those batteries slowly and carefully. LIPO batteries are very susceptible to coldness and will result with shortened flight times which, in the extreme, can be as short as just seconds. However, I've not heard of freezing batteries to swell but that doesn't surprise me...if a battery is stressed in any way, anything can happen even swelling. Note that a battery may swell further when it's in the battery bay and thus prove impossible to extract without disassembling the aircraft.

Any battery that has swelled must be treated with caution even if that swelling has subsequently gone down. To me, a swollen battery is a dead battery that should be disposed of...it's not just about the likelihood of your aircraft crashing in a ball of flames: There is a heightened risk of it catching fire in your house and injuring (or worse) your family.
 
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If you're not going to be using the batteries within a week to a month you should store them with about 60% charge. This is because Yuneec's batteries are not smart batteries so they won't discharge slowly with time. I believe the swelling is from the change in environment causing a fully charged battery to essentially "overcharge" without being plugged in (I may be wrong, don't quote me). I use to keep one battery fully charged in case of a last minute project (which didn't happen for several months) but that battery now has cell issues and is swollen but the others that I've kept around 60% are just fine. I'd say that since there was such a drastic drop in temperature on the batteries that you've had a similar effect even though you probably didn't let them set fully charged for months.
 
As far as landing gear issue, turn on your Controller and H, lay the H upside down, then flip you gear switch up and down position. This will put the landing gear in the right position. Do this without propellers attached, and with a non swollen battery
I had a similar issue that did not resolve by attempting to cycle the gear with the H upside down. The solution was to pull the offending gear and its motor out of the body (2 screws) and using a 9v battery to activate the gear motor. No problem since. I think the little gear motor can get over extended into a part of the mechanism that doesn't move freely.
 

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