tim.moland

I purchased a Trex 600 electric used. It came with four used lipos. After setting everything up on my DX7, I test flew it for the first time. A fully charged battery only lasted about thirty seconds until the motor started to spool down like the battery was low. I thought a had forgot to charge that battery, so i tried another one i knew was fully charged. It ended with the same result. I have used all four batteries and have got the same result. The batteries all check between 4.13 volts per cell and 4.17 volts per cell after the 30 second flight. I have consulted the esc manual thinking the cutoff voltage was set real high but everything seems to be set correct according to the beeps when the battery is connected. I am fairly new to esc and lipos, so any input will help. Help, I just want to fly!!

USHobbySupply

what batteries are you using? What is the cell count and mah?

tim.moland

All four batteries are 6S. Two are air thunder 5000MaH. The other two are Flightpower 5350MaH. As I said before, all four batteries are used and came with the helicopter. I have no idea what condition they are in, but I have a hard time believing all four batteries would yield the same results while flying.

USHobbySupply

well, one thing is all batteries could have been abused and are not putting out the power anymore. Its possible, but as you mentioned, probably unlikely.

Did you query the seller to see if they had this issue?

As the 6s batteries are quite expensive, its a hard pill to swallow if you have to get another battery.

I get about 6-8 minutes on my trex600, with a 6s5000mah.

Maybe there is excessive drag in the driveline? Maybe the esc is overheating and cutting out? How hot is the esc when the 30seconds are done?

tim.moland

The helicopter was sold through a hobby shop so i didnt have direct contact with the seller. I did however buy a Trex500 from the same individual and have had excellent results, so i don't think he ripped me off(hopefully). I have not checked the temp on the esc. That was another possibility I thought of, but I was not sure how hot it should be. I think the manual says it will shut down if it reaches 85 degrees, but that seemed real low to me. Either way, replacing an esc or a battery are expensive. I was wondering if there was a programming error on my part, cause the helicopter flew before i bought it.

OldScaleGuy

My Feedback: (2)

Sure sounds like a battery problem.
You live in a well popluted area, have you got a friend in the area that has a 6S you can try in your 600? That would prove whether it is your packs or some other problem.

KCinNC

i would check the volts per cell after flying...just to see if they are in the same ballpark....could have a bad cell

USHobbySupply

I think the 85 degrees referenced Centigrade, not Fahrenheit. 85c would be close to 200 degrees F (off the top of my head). Does it get too hot to touch or hold for 3 seconds?

Rafael23cc

My Feedback: (6)

Tim:

Are you in contact with the heli pilots in the Wichita area? There is a wealth of knowledge in your city that you could be benefiting from.

If you need help contacting some people let me know.

Rafael

tim.moland

I checked two of the four batteries after flying them. One pack showed 4.17 volts per cell. The other showed 4.13 volts per cell. Thats still a good charge isn't it, or did I figure wrong.

tim.moland

I have yet to make it to the field to fly it again. Ill get back to you on the temp. of the esc. I will ask to borrow a battery from the other guy that flies a 600E at my field, or have him try my battery in his bird. Thanks for the info guys.

baurwin

did u program the esc when u set it up on ur tx? maybe the voltage cutoff is not set right??

i had the same thing happen on my 450 when i first got it, it was in the programming. i reprogrammed the esc and all was good.

tim.moland

Ok, I double checked the ESC, it is programed right. The cutoff point is programmed at 2.9 volts. I did some hovering this morning and took some additional data from each of the batteries. I flew all four batteries again. The speed controller was warm on all flights but I had no trouble holding on to it, so it wasn't overheating.
BATTERY#1 (FLIGHTPOWER EVOLITE 5350MaH) FULLY CHARGED 25.2 VOLTS TOTAL FLIGHT TIME: 30 SECS.
CELL#1 4.2 CELL#2 4.2 CELL#3 4.2 CELL#4 4.2 CELL#5 4.2 CELL#6 4.2
DISCHARGED 24.62 VOLTS
CELL#1 4.09 CELL#2 47.10 CELL#3 4.08 CELL#4 4.10 CELL#5 4.10 CELL#6 4.11

BATTERY#2(FLIGHTPOWER EVOLITE 5350MaH) FULLY CHARGED 25.19 VOLTS TOTAL FLIGHT TIME: 35 SECS.
CELL#1 4.18 CELL#2 4.18 CELL#3 4.19 CELL#4 4.19 CELL#5 4.19 CELL#6 4.18
DISCHARGED 24.62 VOLTS
CELL#1 4.10 CELL#2 4.10 CELL#3 4.11 CELL#4 4.10 CELL#5 4.11 CELL#6 4.10

BATTERY#3 (AIR THUNDER 5000MaH) FULLY CHARGED 25.24 VOLTS TOTAL FLIGHT TIME: 42 SECS.
CELL#1 4.19 CELL#2 4.19 CELL#3 4.19 CELL#4 4.18 CELL#5 4.18 CELL#6 4.19
DISCHARGED 24.45 VOLTS
CELL#1 4.09 CELL#2 4.07 CELL#3 4.09 CELL#4 4.06 CELL#5 4.07 CELL#6 4.07

BATTERY#4(AIR THUNDER 5000MaH) FULLY CHARGED 25.19 VOLTS TOTAL FLIGHT TIME: 60 SECS.
CELL#1 4.19 CELL#2 4.18 CELL#3 4.19 CELL#4 4.19 CELL#5 4.19 CELL#6 4.19
DISCHARGED 24.32 VLOTS
CELL#1 4.06 CELL#2 4.04 CELL#3 4.05 CELL#4 4.04 CELL#5 4.06 CELL#6 4.06

That all being said, all the batteries seem to have good cells in them. Is there any other way a battery could still have good voltage but have a bad capacity? Am I going about this wrong?

OldScaleGuy

My Feedback: (2)

I have seen that on one other occasion. The battery (just one in this case) seemed to charge fine, hold voltage but just did not have enough to maintain flight for any period of time. It was a 3S in the 2000mah range. It has been some time ago so the details are a bit vague. Not being an electronics expert by any means, I still don't know why it didn't work, it just didn't. A good battery in the same heli and it flew fine.

KCinNC

hope you get it figured out man...that is too awesome of a heli to be able to fly it for only 30 seconds at a time

tim.moland

Thanks guys. I will post again when I figure it out.

Rafael23cc

My Feedback: (6)

Did you read my last post? Do you have help trying to figure this out, or do you want to do it by yourself? It is one thing to come here and ask for help, but it is very different to have another pilot right in front of you.

Rafael

bionicbone

I too only have a little experience in this area but I believe you are correct, it is possible for the battery voltage to drop extremely low as soon as you try to draw a load from it and then shoot back up when the load is removed. Although having 4 batteries all in the same condition would be more than bad luck (
You should always measure battery voltage under load, I have in the past attached a LED cell volt meter to the back of my heli so I can hover in and check the voltage.

Steve Collins

My Feedback: (8)

Three of my 4 Air Thunder 6S 5000ma batteries have also done this. The fourth one seems fine. I also have a ThunderPower 6s 5000ma that has never done this.