CARLOSHUGGINS

Hi.... I have 4 battery packs and 3 of them when I plug it into the balnacing charger after 30 seconds or so the charger stars to blink both leds.... this according to the manual and the charger's stickers means a charging error... how can avoid this??? how can I troubleshoot the charger or the batteries to see what is wrong... the batteries ar all new it have been charged like 16 times only.... I don´t think the battery life is that short.... any help would be apreciate it....

Wolfpackin

What batteries?
Which charger?
How long are your flights?

CARLOSHUGGINS

Charger: 2-3 Cel 7.4-11.1V LiPo Balancing Charger
Batteries: 7.4 800mAh 2 Cell LiPo
Flying time: around 20 min

Need some other info???

Wolfpackin

If you mean you fly for 20 minutes per battery then you have destroyed them.
I would check the total voltage and voltage per cell with a meter.
My guess is they have been run to low, a death sentance for a lipo.
If you have not overdischarged the batteries then it could be a defective charger.

Druss

I doubt that he's actually flying for 20 minutes, he might be out with the battery connected for that long but actual flight time is probably half that.

Do check the batteries though, get a voltage meter and check the total voltage and the voltage of each cell. Each cell should be between 3v and 4.2v.

ThinAir

Each cell should show the same voltage, though, right? That's the importance of having a good "balancing" charger. What would be an acceptable difference between the two cells, and associated probems if the cells weren't reasonably balanced? I would imagine imbalanced power to the dual motors leading to torque differences, thus more difficult heli control. But could there be potential damage to the battery or other elec components if the voltage was too imbalanced?

I can turn on a light switch, and I know how to measure/test the cells with a volt meter, but couldn't tell you the difference between a volt and an amp, lol.

Druss

You want to keep the cells balanced so that no one cell fails while the others don't . You would still get the same total voltage so there would be no imbalance of power out of the battery but continued use and unbalanced charging would eventually kill a cell.

For instance, say you charged the battery but the balance was off. the cells of the batteries are in series so you add the voltages of the individual cells to get the total voltage. So you could have one cell at 4.5v another at 4.2v and the third at 3.9v... this would give a total charge of 12.6 volts. So you use the battery and discharge until you reach the 9v minimum, in that case though the first cell is at 3.3v, the second at 3v and the third at 2.7v. You have now damaged the third cell and it may puff. You may also have damaged the first cell by overcharging to 4.5v instead of the 4.2v maximum.

This type of unbalancing occurs because not all cells charge and discharge at the same rate, matched cells are very important but sometimes, especially with low quality batteries, the manufacturer does not have the quality control (or just doesn't care) to make sure all the cells are matched closely. If you get unmatched cells and use a poor charger then the imbalance keeps getting worse until you damage the battery beyond repair.

ThinAir

Druss, thanks. Good explanation! If they're not perfect it looks like the balance between the cells should be within about 0.1v or so. Are balancing chargers capable of achieving that, or better? Do you always put a meter to the cells to check them after charging? I wonder if they sat on the shelf for a while (2 weeks, 2 months, longer?) if the cells would "discharge" at a different rate and you should check, or recharge, them again before using them.

I've checked mine and they looked good, but that's with an old meter with a needle that reads nowhere near that precise. (Or is it just my eyes, lol.) I see another upgrade coming, a digital meter. This hobby gets you from all directions, but worth it.

wkmc

Check your 12v source is at full capacity as this can cause the leds to flash as the the source voltage drops.

UTM

The only way I can see him overdischarging a battery like that is if you were to leave it plugged in after the flight was over. I always fly my helis (CX2,Falcon40) until the skids touch the ground and won't lift any more. I am always in the 3.4-3.45v range when this occurs. I am at +-750 above sea level. Balancing is an issue as described above. If the cells are too far off you could potentially damage one cell and not the others. I use the Eflight C505 balance charger and it will always balance my cells perfectly. I'm at 4.20 per cell at the end of charge on all my packs. Well actually my original CX2 pack will only charge to 4.19 per cell. It's my oldest pack but still the cells are balanced. So to answer your question a good balance charger can accomplish perfect balance every time. I tested the charges of my CX2 packs when I first got this charger. I charged them up with the stock eflight balance charger and then plugged them up to the C505 and found that the stock charger did not do a good job balancing. I found the difference was on line with .02-.03v difference in cells. The exact numbers of the two packs I tested were 4.37, 4.39 and 4.36, 4.38 when completely charged on stock charger. The C505 proceeded to put them to 4.20v per cell in short order. I would recommend getting a good charger. They can be expensive I know but consider it an investment in the hobby. Besides it will eventually pay for itself through extending battery life.

GundamWZero

I have the E-Flight 3-cell Li-Po charger, but whe I try to charge the battery the red LED stays flashing. When I rad the fault it says that the battery is not connected, but it is
!! Can anyone help with this?

jp473

Most likely a loose wire. This has happened several times to me. Get a volt meter and check each lead at the tip of the plug. If you find a lead that is not getting a reading you have 2 potions. Get another battery or boldly go where only the few have gone before and take the battery apart. Not recomended for the average person. Re-solder the connection. Do Not Do This unless you are completely comfortable with it and have an emergency plan in place should something go wrong? Don’t mean to scare you but these batteries can go boom.