Well I lost my Me262 after takeoff today...had flown it four times and on the fifth flight put my standard Admiral 5000 in it and checked the charge...read 100%....had balanced charged in the night before....right after takeoff power rolled back quickly and I tried to bring it back to field but was too low and tipped stalled it..........I had the same thing happen to me last week with my F18...fortunately I got that one back....The battery charged fine, indicated 100%, all cells looked fine....battery was two years old.....is this common for a lipo to just give out like this?....checked battery after crash and it seemed ok....
-
-
Knowing what the IR of the cells will tell a lot.
Warbird Charlie
HSD Skyraider FlightLine OV-10 FMS 1400: P-40B, P-51, F4U, F6F, T-28, P-40E, Pitts, 1700 F4U & F7F, FOX glider Freewing A-6, T-33, P-51 Dynam ME-262, Waco TF Giant P-47; ESM F7F-3 LX PBJ-1 EFL CZ T-28, C-150, 1500 P-51 & FW-190 -
First thought is: Inability to deliver demanded current. LiPos lose ability to deliver current before they lose significant capacity. I normally see this at 3 to 3.5 years.
One case of it means you just can't use it for an EDF any more. It might give up to 2 years more service at half the current demand.
Each flying season I do battery tests. I put them in the highest demand plane appropriate to the battery and check how long (on the ground) they will deliver full throttle.
***********
It could also be solder joint going bad or the connectors between the ESC and connector. I've also melted down a 4mm banana bullet in flight once (the bullet, not the solder, arced to slag) and melted the solder joint on an EC5 once.
Same test as above and feel to see if the wires/connections are getting hot. Warm is OK when pulling 100 amps... but it should never be too hot to hold.
*************
On loss of power GET THE NOSE DOWN.
Pull throttle back.
Try 1/2 throttle. If its LVC due to inability to deliver current, that's appx 1/4 current and should give thrust for maintaining flight, possibly a slow climb.FF gliders and rubber power since 1966, CL 1970-1990, RC since 1975.
current planes from 1/2 oz to 22 lbsComment
-
Same thing just happened to me. Got my plane down OK. I checked the IR and it was at 50! The battery is only 2 years old. I have others that are this old and are only at about 28-30. It pays to keep an eye on that IR. Once they reach 30 they seem to go down hill fast. DocComment
Comment