|
|
Post by coffinsnail on May 1, 2009 21:51:50 GMT -6
Saw this in RC Heli Magazine.
Lipo Swelling Gauge
|
|
|
|
Post by Dave on May 2, 2009 8:33:33 GMT -6
Good ideal.
Dave
|
|
19000rpm
Moderator 
FIRST 30 MEMBER
Posts: 5,183
|
Post by 19000rpm on May 2, 2009 14:26:39 GMT -6
HMMMMM. If you can't see the swelling or feel the swelling accompanied by heat you really do need a set of calipers...And have them hooked up the a smoke detector, auto dial to the FD and your home fire supression system. ;D
Seriously though; you're more apt to see indications that your lipo is going bad on discharge rather than charging. Flying puts a lot more pressure on the battery than does normal charging (charging at around an amp) so test the battery by eye and feel right after flying to monitor your lipo's health.
Happy landings
|
|
BTCat
First 30 Member 
FIRST 30 MEMBER
BT Cowboys Cruiser
Posts: 2,213
|
Post by BTCat on May 2, 2009 20:06:54 GMT -6
HMMMMM. If you can't see the swelling or feel the swelling accompanied by heat you really do need a set of calipers...And have them hooked up the a smoke detector, auto dial to the FD and your home fire supression system. ;D Seriously though; you're more apt to see indications that your lipo is going bad on discharge rather than charging. Flying puts a lot more pressure on the battery than does normal charging (charging at around an amp) so test the battery by eye and feel right after flying to monitor your lipo's health. Happy landings Okay, before I ask, I will tell you I already know the Lipo I am using for my EXI 450 is too low of a c rating. It was a freebe GE Power 11.1 2200mah BUT it does not state it's discharge rate. And it does get hot when flying. My question is how hot is too hot? |
|
|
|
Post by coffinsnail on May 2, 2009 21:31:09 GMT -6
hey i just thought it was a good tip for new flyers, especially since heat does not indicate a bad battery mine is hot after a flight but has not bulged yet and seems to charge and refly just fine. but with his tip above it can be measured in 10ths or 100ths of a mm so that means youd see it on the calipers before you saw it or felt it with your eyes.
|
|
|
|
Post by lowbudget on May 2, 2009 23:05:18 GMT -6
BT can you squeeze the battery with your fingers - do you want to turn it loose just as soon as you squeeze it - if so i would say it is to small a of a C rating ;D = VIC
|
|
19000rpm
Moderator
FIRST 30 MEMBER
Posts: 5,183
|
Post by 19000rpm on May 3, 2009 7:44:14 GMT -6
Right vic, too hot to handle is too hot.
I see the GE 2200 at 2 different C's 25 & 30. A 25C should be adequate for most 450's BT, so maybe you've got a bad battery or there's something in the set up, pinion to main gear spacing, that's putting extra drag on the motor.
Have you balance checked the battery? What is the volt reading after charging?
I wasn't busting your chops coffin, I just know from experience you'll know you've got a bad pack long before it becomes a a "burning issue" without resorting to calipers.
Happy landings
|
|
rtfheli
DEALER 
FIRST 30 MEMBER
"Live to Fly"
Posts: 867
|
Post by rtfheli on May 3, 2009 9:14:25 GMT -6
I have to agree with 19000RPM, you'll know when your battery is heating up or bubbling after flying. A low discharge rating 'c' is not recommended for the larger power hungry helis. Don't go cheap on the lower 'c' ratings. IMO, a 25c discharge rate is the minimum. A lower rating will cause bubbling and heating up quick.
|
|
BTCat
First 30 Member
FIRST 30 MEMBER
BT Cowboys Cruiser
Posts: 2,213
|
Post by BTCat on May 3, 2009 11:03:47 GMT -6
I can handle the pack okay after flying, but I handle a lot of hot stuff at work. Not necessarily a good test. I'm the guy who can reach into the hot water to get my corn on the cob without tongs  I have an infrared. I'll shoot it after I fly today. I shoot it yesterday, but I forgot what it was. I think around 140*. The motor, ESC, servos, etc were cool (all less than 80* on a 77* day). I have a 25c battery on order and will probably order a couple of 25c cheapos today. My ESC starts reducing power, and eventually cuts it when the voltage reaches a certain point. It will do this after about 3 to 5 minutes, but the total voltage is usually 11.5 or so when I check it after that. I am assuming the high draw is reducing the voltage too much in flight (a lot of hovering). I have a new charger arriving tomorrow. In the meantime, I am using the cheapo Esky balancing charger at .8 amps. I checked the cells, it is cutting off at 12.59 v total with balanced voltage across each cell. I'm sure this battery is just too small or maybe going bad. But I would like a point of reference for my future knowledge. No puffing, BTW. Just for grins, I think I'll put the calipers on them before flight, after flight and during charging. Probably TMI, but what else am I going to do with my time with just one battery  I'll post the actual temp later today. |
|
|
|
Post by lowbudget on May 3, 2009 11:20:51 GMT -6
the battery is fine - it is only .01 short of the 12.60 volts ;D = VIC
|
|
BTCat
First 30 Member
FIRST 30 MEMBER
BT Cowboys Cruiser
Posts: 2,213
|
Post by BTCat on May 3, 2009 11:45:20 GMT -6
the battery is fine - it is only .01 short of the 12.60 volts ;D = VIC Now If I could just find the balance connector on the pilot |
|
|
|
Post by lowbudget on May 3, 2009 11:57:52 GMT -6
install a co-pilot on the heli ;D = VIC
|
|
BTCat
First 30 Member
FIRST 30 MEMBER
BT Cowboys Cruiser
Posts: 2,213
|
Post by BTCat on May 3, 2009 13:12:42 GMT -6
install a co-pilot on the heli ;D = VIC I think you just volenteered to finance??? ;D Okay, I didn't run this thing hard because I was too busy checking stuff between runs, but what I have is this: After 3 minutes into the first run, the ESC reduced power and then cut throttle. I checked voltage -- 11.47, temp was 104. Restarted. Got another 2 minutes. Voltage ~11.21, temp 107. Restarted. Got 1 minute before ESC shut down. Final voltage 10.97. Temp 108. All cells drained evenly. Bottom line to me is cheap battery with low C rating.... |
|
19000rpm
Moderator
FIRST 30 MEMBER
Posts: 5,183
|
Post by 19000rpm on May 3, 2009 13:29:49 GMT -6
I don't think 107 is too hot. That's not even 10 over body temp. 140's pretty warm.
There's nothing wrong with the voltages before or after flight.
I bet you can also turn the steaks on the grill with your fingers. The hottest thing I can handle is a mug of coffee. ;D
Happy landings
|
|
BTCat
First 30 Member
FIRST 30 MEMBER
BT Cowboys Cruiser
Posts: 2,213
|
Post by BTCat on May 3, 2009 13:46:03 GMT -6
I don't think 107 is too hot. That's not even 10 over body temp. 140's pretty warm. There's nothing wrong with the voltages before or after flight. I bet you can also turn the steaks on the grill with your fingers. The hottest thing I can handle is a mug of coffee. ;D Happy landings Yea, I was trying to push it when I got it to 140. No, I don't flip steaks that way. Don't want to ruin the steak ;D |
|
