Lipo - a tad swollen

[DebianDog]

I've got a 450se with a stock align 11.1v and a true power lipo with the same specs. I'm charging these lipos with a triton jr charger. I plug the battery into the triton (deans connectors on both batteries) and the charger detects the battery and it charges. The align battery usually takes about 30-45 mins to charge then the charger beeps when it's done. The True power battery takes about 10 mins and it lasts less than 2 mins.

IMO both my batteries cannot be used after just about 5 flights and I need to find out if they really cannot be used/repaired/brought back and what probably caused the problem and finally what are the best batteries IYO for my rex.

Detail of problems:
On the Align lipo, it just suddenly stopped working. I realized this when after a normal flight (usually hovering as I'm a novice) I plugged the batt into the triton to recharge and it couldn't recognize the battery. Plugged the battery into the esc after and not an beep was heard. I never over discharged the battery. The connectors are good and strong but I'm not sure about cold solder etc. Please advise.

On the True power lipo, I realized I began to have problems when I charged the battery one day and it became a tad swollen. The usable time on that battery is just under 2 mins and it charges in about 10 mins. Could this battery be brought back by any means.

Basically I need to know if either of these batteries can be salvaged. I live in Trinidad and I just cannot go to my hobby store and buy new ones and both my birds are down. New batteries means waiting about 4 days for them to get here after ordering online. Most importantly I need to know if I'm doing something wrong so that I do not damage other batteries.

I'd really appreciate some advice here and thanks for reading all of the above.

[DebianDog]

No mention of a balancer?

[Rickinferno]

where is the original post? Seems like he needs to get a balancer and charger that shows how much goes back in the lipo...

Rick

[peterob]

Looks familiar (http://www.helifreak.com/viewtopic.php?t=35207).

[DebianDog]

where is the original post? Seems like he needs to get a balancer and charger that shows how much goes back in the lipo...

Rick

He did not want to post in public so he PM'ed me about it. :dontknow

[peterob]

Short version of the manual page is: the charger doesn't detect voltage and capacity, you have to set it each charge.

It defaults to 350mah (no idea what voltage), so 45 minutes would only put back 260 or so mAh. The cells were probably way under voltage after 5 flights.

[Rickinferno]

I think peterob just explained what happend to the lipo"s.

Rick

[Jermo]

where is the original post? Seems like he needs to get a balancer and charger that shows how much goes back in the lipo...

Rick

He did not want to post in public so he PM'ed me about it. :dontknow

ROFL... check the lipo forum, Trinheli has at least 3 threads running for this.. :D

[Gary JP4]

One can only speculated where you stand or why this happened with the information given. If your friend is not going to participate in the discussion then it will be hard to pin down what really happened and how to avoid it next time. Also, since you mention puffing in the title probably both, or the one(s) that are puffed are toast. I have one that puffs a little every time I fly it. Its capacity is reduced and I can fly for 5 minutes with it. This would not be possible without a balancer.

But, lets speculate anyway on what could have happened?

Background:

Overcharge = possibly ruin cells, cause imbalance, catch on fire, explode. Fire spreads through burning liquid spuing all around for several feet.

Over discharge = ruin cells, puffing, cause imbalance, less chance of fire but possible with a high discharge rate like a Short

I plug the battery into the triton (deans connectors on both batteries) and the charger detects the battery and it charges.

This is the first problem, charging through the Deans means no balancer. All or one cell(s) could have been over charged. Maybe you could over charge the whole pack by being in the wrong mode like Nicad. More likly one or more cells could have been overcharged even if the charger was set up and working properly because no balancer was used. Since the charger is looking at the total voltage in series when plugged into the Deans connector it can't tell what individual cells are doing without using a balancer. One cell can be overcharged (voltage too high) and the others two low resulting it a total voltage that is normal. This is the "out of balance" condition and could have resulted from over discharging in flight. If the battery was not fully charged and then flown this could have caused the over discharge even with short flight times. Starting from an over discharged condition is more likely to cause cell imbalance. This is a vicious cycle. So, it is important to start with a fully charged and balanced pack. The only way you can assure this is with a good charger and balancer that shows voltage while charging and when finished and amp hours (mahs) put back into the pack.

To see where you stand at this point I would charge both batteries using a balancer and then discharge using your charger at 1.0 amp and a balancer down to 3.0v per cell. That is a cycle (you usualy do the discharge portion with a flight). I would cycle 2 or 3 times to get the packs into balance and see what the capacity is when balanced. Note the mah's on discharge and charge. They should come up in following cycles if this is going to work. If the charger does not recognize a pack it is probably because it is overdischarged (under 3.0v per cell). The charger will not recognize a pack if it is under some voltage threshold (I think 3.0v per cell on your JR). So if the pack is under 9.0v that charger will not take it. Given your level of knowledge about Lipos I wouldn't suggest trying to recover that batterie(s) yourself but, a pack can be recovered from low voltage by manual charging with approximately 12v for a minute or two until the pack comes up above 9.0v and then the charger will recognize it. Some chargers have a function for this like the Cellpro 4s They call it battery recovery mode.

You need to get a crash course in Lipos and get a balancer. This was an expensive lesson. IF any good can come of it, it might be to peak your interist in learning about Lipos. The leason is not over yet. Even better than adding a balancer to the JR would be to get a balance charger like the Cellpro 4S or e-station BC-6. They call the Cellpro plug and play and walk away. That may be an exaggeration but it is more true then with most chargers.

The concept of flying a short flight and then charging and noting mah's used and then adjusting flight time untill you achive 80% usage of the capacity in mah's is based on starting with a fully charged and balanced pack. If you overdischarge it on the first filght and don't use a balancer for charging it back up you can get screwed pretty quickly. You have quickly violated most every good rule of thumb on Lipo use and care.

Summery: Use a balancer with the Triton or get a balance charger. Always use a balancer. These packs may be toast but, if you were starting with a new battery charge it using a balance charger, fly a short flight like 3 minutes, charge it again and note mah's put back in. If it is less then 80% fly it a little longer until you are using about 80% of the packs capacity. With a 2100 mah pack 80% is 1680 mah so that is what you are shooting for using during flight and putting back into the pack.

This might seem overly complicated but it is the same as timming a nitro flight using fuel so you don't run out of gas. Just that with Lipo's you don't know when you ran out of gas because it doesn't quit. You have to charge it back up to see how close you came to running out of gas and you can't run Lipo's untill they are dead and then just charge them back up.