Harleysr1

New to electric flight and bought a profile 3D Cap232 "no name" and came with no name ESC and motor. Built the plane, On my first battery a 11.1 volt 1500 Mah 3 cell Apogee the instruction say the battery it is about 50% charged to I used it out of the package to set throws Etc with no problem. I Put the battery on my hobbico battery charger that says in will charge Lipo's and 2 seconds after I hooked it up the alarm sounds "full charge". So now I am think I have a problem But is it my battery of the charger. I put the battery back in the Cap 232 and will I hit the throttle and she runs right now until it will not spin the motor. Tells me battery is dead, So to confirm I hooked it up in the ParkZone Typhoon and same thing dead battery. So I went to the hobby store bought a new battery and E-flites Lipo charger, Get home charger the battery I think it took about 30-40 minutes to charge. Took it to the feild and flew it, Charged the battery and flew it, Then charged it again, this time it only took about 15 minutes to sound fully charged. BUT now that battery also sound the alarm fully charged and it is dead as dead gets. I thought I read in the instructions to the ESC that the 3 motor to ESC leads can be hooked up any way unless the motor runs in reverse then switch any 2 leads which I did.... can this ESC have a problem and damaging my batteries? "sorry so long!!!

Joe

jdetray

Hi Joe-

You may have discharged your lipos too far. A lipo that is over-discharged (that is, discharged to too low a voltage) may be damaged, so most chargers check the pack voltage, and if it is too low, the charger won't charge the pack.

"Lipo-friendly" ESCs are available with a low voltage cutoff (LVC) that reduces or cuts off power to the motor before the lipo voltage drops too low. Your ESC may have the LVC set too low (or it may have no LVC at all), allowing the lipos to be over-discharged.

[link=http://www.rcgroups.com/forums/showthread.php?t=209187]Read this discussion thread for more information.[/link]

If you plan to stay with electric flight and especially if you plan to use lipos, it is strongly recommended that you have a meter that allows you to measure the voltage of your battery packs. Even better is a so-called wattmeter that measures both voltage and current.

- Jeff

exeter_acres

My Feedback: (2)

agreed...sounds like you over discharged them...

what is the voltage of the packs after flight?

Harleysr1

Jeff Thanks for the reply. I dont know alot about the ESC as I cant find the paperwork on it. I did read the ESC sheet with the Parkzone Typhoon that I bought and it taked about the LVC. How do I know what to set the LVC to? or at what volts are too low on Lipos' I know I checked the volts on the battery and it was way down around 2.5 volts. Are you telling me that the (2) batteries I got are trash? or is there a charger that will charge them if they get too low? I am not ready to give up on the electrics right yet. I did buy a E-flight Ultimate with a E-flite 400 outrunner and E-flites 20amp ESC. Do these wattmeters cut off the battery before it gets too low? Thanks again

Joe

Harleysr1

2.5 volts is what the battery is checking now

Joe

exeter_acres

My Feedback: (2)

for a 3 CELL???????


You killed it... the pack should really never go below 9v (3v per cell)
either use a timer, a lipo alarm, or the absolute second that you feel a loss in power... land...

you cannot run Lipo's down like that...

get a bucket, put some water in it. mix in a bunch of salt and give your batteries a bath and throw them away......

Harleysr1

Boy it didnt take very long of a flight to get them to that voltage. If the ESC has a LVC then It would shut the motor down at a specific voltage correct? and 3volts per cell is the lowest I would want to voltage to drop to? These Wattmeters mount on the plane and sound a becon that tells you to when the voltage gets low? Do Lipo's get better longer life after they have been charged/discharged a few times?

Thanks
Joe

jdetray

Hi Joe-

Yes, 3V per cell is the recommended minimum for lipos. Going below that usually means the batteries are damaged. If they are just slightly below 3V per cell, they can sometimes be recovered, but at 2.5V for an entire 3-cell pack, I doubt there is much hope.

The wattmeters are not airborne devices. They are for measuring voltage and current on the ground.

Small warning devices are available that fit in a plane and signal you with light or sound when your battery voltage gets too low. But most people instead use ESCs with the correct LVC for their type of battery. That's the easiest way to do it. When the ESC detects that battery voltage getting low, it cuts or reduces power to the motor but maintains power for the receiver and servos, so you can land the plane.

Lipos generally do not get better with age, although at least one manufacturer (Thunder Power) recommends not pushing them to their maximum specification for the first few flights.

If your flight times are shorter than you expected, it could be that your power system is drawing too much current for those particular batteries. The solution might be larger batteries or ones with a higher "C" rating. This is one good reason to purchase a wattmeter -- so you will know how much current your power system draws and can then select batteries accordingly.

By the way, a wattmeter looks like this:



- Jeff