Topic: Issue charging an 11.1v Lipo (Read 5415 times)

goBulawayo · « **on:** May 25, 2013, 08:04:15 pm »

Hi All, I am having an issue charging my 11.1v lipo, 2200mah - I have just placed it on charge for tomorrow and after only about half an hour it has said full but the counter on the bottom right of my charger screen (LiPro Balance charger) only showed about 514mah, it used to go right up to around 2200 (actually a bit more probably closer to 2300) - Any thoughts on what the issue might be please

It did this to me a couple of weeks back and I just thought maybe it still had charge in it but when I ran my Perkasa, it barely lasted 5/8 minutes before my alarm went off. I used to get a good 15 odd minutes out of the same battery.

Many thanks Wayne

Bill D203 · « **Reply #1 on:** May 25, 2013, 08:08:27 pm »

In short
RIP LIPO. Maybe time to buy another.

goBulawayo · « **Reply #2 on:** May 25, 2013, 08:10:42 pm »

Crumbs I hope not only used it about 8 times - Thanks Wayne

Bill D203 · « **Reply #3 on:** May 25, 2013, 08:12:49 pm »

Try takeing out and running it down then give it a very slow charge say max 500 ma . This may help it. Best of luck.

kmmbcwebmaster · « **Reply #4 on:** May 25, 2013, 08:13:40 pm »

Try using a cycle charge if still the same then affraid it is RIP for your lipo

goBulawayo · « **Reply #5 on:** May 25, 2013, 08:15:28 pm »

Right whats a cycle charge please, don't recall seeing that in the charger handbook

Bill D203, thanks I will try a slow charge after running tomorrow

Wayne

kmmbcwebmaster · « **Reply #6 on:** May 25, 2013, 08:23:56 pm »

If your lipo charger is the computer type you should have either a cycle option which slowly discharges the battery to almost zero then slow recharges or could have a discharge option but will have to set to recharge yourself

goBulawayo · « **Reply #7 on:** May 25, 2013, 08:32:00 pm »

Ah thanks, is has a discharge option and then I can re-charge it

Wayne

kmmbcwebmaster · « **Reply #8 on:** May 25, 2013, 08:41:03 pm »

Lipo are a little like nimh batterys if you just keep topping them up then sooner or later they stop holding full charge .so its worth taking the time to cycle charge the battery about once a month to keep them in good order

goBulawayo · « **Reply #9 on:** May 25, 2013, 08:52:56 pm »

Thanks kmmbcwebmaster - I will set it up to cycle charge

Regards

Wayne

kmmbcwebmaster · « **Reply #10 on:** May 25, 2013, 09:01:21 pm »

Your welcome

Ron

goBulawayo · « **Reply #11 on:** May 25, 2013, 09:55:07 pm »

Another question if I may, can I stop a charge half way through and then restart it later? I have a 5500mah battery on charge at the mo and its only at 1500 odd, I don't want to leave it unattended over night - Will restart it tomorrow

Thanks

Wayne

AlisterL · « **Reply #12 on:** May 25, 2013, 11:43:12 pm »

Quote from: kmmbcwebmaster on May 25, 2013, 08:41:03 pm

Lipo are a little like nimh batterys if you just keep topping them up then sooner or later they stop holding full charge .so its worth taking the time to cycle charge the battery about once a month to keep them in good order

Respectfully, I disagree with this - unless the battery in question is not being reset to storage voltage after each charge or use. LiPos are not subject to the "memory effect" - but we should all be aware that they do typically sustain fewer charge/discharge cycles than other chemistries - but the chemistries do degrade over time, like any battery. A LiPo should not be left either fully charged or discharged as those states will affect the chemistry of the battery. A LiPo left at storage voltage will last months without attention and can readily be used following a full charge without any other preparation.

If I may also comment on charging at a low rate, in my opinion this is unlikely to make a difference and if it does it I would be even more concerned about the battery - as that would imply that the chemistry is failing at 'C' values. I'm not aware of any LiPo that is NOT made to be charged at it's 'C' rating - and this is also true for LiPo/LiFe tx packs that are rated at low multiples of 'C' for discharge.

Wayne, you should physically inspect the battery - if it is bulging or bloated on any of the cells this would be an indicator that it has failed. Likewise if it has been physically damaged at all (battered, bent, poked, dented) then this could be a cause of the problems you are seeing. Also, when the battery is charging you should check it's temperature. Charging at 'C' should not cause it any stress and it might get only a little warm. If it is hot when charging at 'C' or when in use then these are signs of failure and you should stop using the battery.

It may be that you you got a dud - it does happen.

With regard to restarting the charge yes you can - presumably you are using a computerised charger - this will just read the current battery voltage and charge to full based on the # of cells and the 'C' rating you specify. Leaving a battery for a short time in any state of charge (as long as it's between the min. and max. voltages) is very unlikely to cause harm.

Regards,

Alister.

grasshopper · « **Reply #13 on:** May 26, 2013, 01:50:26 am »

Could you be more specific about your charging regime?

A good LiPo charger should have a facility to balance charge your battery, where it compares the voltages of each cell in the battery and charges them so they all reach their maximum voltage together. Although it isn't necessary to do it every time, a periodic cycling and balance helps to prevent this situation.

Another scenario is that the connections in the battery are suspect - I have had the situation where the tab of one of the cells has been badly soldered causing a bad connection which then overheated in use and melted

derekwarner · « **Reply #14 on:** May 26, 2013, 02:17:27 am »

as grasshopper says..... "I have had the situation where the tab of one of the cells has been badly soldered causing a bad connection" .......knowing little about the black art of electrons

...I thought all of these pre assembled cell sets had fuse welded tabs between each respective cell........
I understood this fuse welded construction was intended specifically to handle the high current draw & hence potential temperature increase..............

........Derek

colin · « **Reply #15 on:** May 26, 2013, 06:11:32 am »

Not sure what has happened posted a reply last night but has not appeared . I have had exactly the same with a same rated battery, a blue coloured one warning LED unit shows charge req then only 5 min on charge till full then short run time. Wonder if thee is a bad batch out there as this was a new battery only charged twice before.
Regards
Colin

goBulawayo · « **Reply #16 on:** May 26, 2013, 09:00:12 am »

Hi All, thanks for the replies - I have had a look over the battery, no swelling on the cells or any visible damage, i have tried to be very careful with the battery to prevent any damage knowing that it can cause issues. I have charged the battery about 8 /10 times, one of those, around charge 8 was a discharge then recharge and this is when it started playing up as it only charged to about half the mah (according to the counter on the charger, an imax B6). Does not get hot when charging either.

As to the charging regime, I ran the battery as acquired when I bought it, left it roughly two weeks then charged it and used it, this repeated over about another 6/8 weeks then charged it a week before I was due to go boating, read somewhere it should not be left full charged with out being used so discharged it, and storage charged it, a week later used it and it did not run very long about 10 min when ususally 15 odd, two weeks later charged again and the troubles started only about 5 min run time, charged on the car whilst at the marina, again only charged up to about half the stated mah and ran less than 5 min.

Will see now later this morning what happens when I run the boat.

I did put my 7.2v lipo on charge last night as well, it is a 5200mah battery, after 160 minutes the charger told me 'time' I am guessing at is not set to charge longer at this stage the counter read about 1500mah. Anyway this morning it went on charge for about 20min and then told me full, counter was at about 100mah-
When I get home I will set this on discharge too then onto a store charge as I won't be using it for another 2/3 weeks.

Colin, my lipo is one of the turnigy blue ones as well

Wayne

grasshopper · « **Reply #17 on:** May 26, 2013, 12:16:18 pm »

Turnigy blue ones, same as hobby king ones just different labels...there aren't that many factories producing batteries in china, just lots of different agents selling them under their own name.

Derek, taken quite a few batteries apart, (mostly RC car packs) a lot of them have a small elongated H shaped pcb in them with the copper lands forming a bridge to put two cells in series, the tags from the individual cell is wrapped round the pcb and soldered into place. Don't assume that they are all welded- the model market demands low prices and so some of the gear you buy is not that fantastic despite the advertising claims - look at the comments about 'Chinese amps' on the other thread.......some cells have even had different C ratings stamped on them within the same battery, and it's usually the lower rated one in the pack that died...

Still sounds like one cell is not charging correctly, connect power lead and balance lead to your Imax, try charging it again at a low ( 1/2 c rate) and when charging press the second button from right, it should give you an individual cell voltage reading, if there's a difference of 0.5 volts or more, switch off and balance charge at 1c rate, if that doesn't help replace the battery.

Gazza · « **Reply #18 on:** May 26, 2013, 06:55:44 pm »

As a Model plane and car buff been using LIPO for years so

PLEASE DO NOT FLATEN to zero volts if you do Bin it because that's it your Li-Po or Li-Fi battery will be DEAD
the cause may be a number of things but best is to put it in a boat or what ever and run it until you see it going slow then wait till its cool
YOU can start- stop charging any Li-Po pack as there not like Nimhs or nicads and do not get hot while charging if they do Switch off and throw out side straight the way

Now the puffing cells . . . well its ok but get ready to bin it as if its in a boat or car this MAY happen and the same apply's if there hot as well

( never ever charge any battery lipo NiCad nimh etc while hot / warm ) always wait till cool
so charging a LiPo its easy make sure you have a LIPO charger and set it to balance charge always the best as this charge's each cell to the correct voltage which is 4.20volt per cell so each cell when charged has 4.20 volt in and set the Amperage as per battery by that I mean if your battery is a 3cell 2200mah then set the charger to 11.1 volt 3cell and the amps to 2.2amp this is known as charging at 1C eg

1800mah charge at 1.8amp
2000mah charge at 2.0 amp
3000mah charge at 3amp
5000mah charge at 5amp

This is known as 1c when they say you can charge at 2c then double the charge so a 2000mah can be charged at 2c it can be charged at 4amps BUT only if it says it on the PACK
Check out picture below

It says at bottom 5c fast charge and only 25c ?
I will only charge my Li-Po's at 1c no matter what it says on the pack . . why well they last longer my plane set I have had for over a year and still running all because I treat them with respect and never let them go low on voltage they do NOT HAVE A MEMORY effect like nicads or nimhs and best is to part charge using your LIPO charger I store mine with a little in so part charge.
If you did this to nicads or nimhs after 3 months they would be flat and you need to cycle them but a Li-Po or Li-Fe will still have a charge and you DO NOT HAVE TO cycle them . . EVER
WHATS 25c
C rating is the power or punch it can handle so if your boat / car / plane has a warm battery then the MOTOR is pulling a few amps and needs a bigger C rating but what does the Crating mean in lay mans terms

Well best way to describe it is a bucket of water ?
Now drill a hole at the top the water spills out and reaches say 3 inch away from the bucket in a small arch this is 20c
Now drill a hole at the middle water spills out and reaches say 8 inch away from the bucket in a large arch this is 30c
Now drill a hole at the bottom water spills out and reaches say 24 inch away from the bucket in a straight line this is 50c
Its down to preassure in the bucket and how much water.
But in the Li-Po case it can give you more power and PUNCH so always get any Li-Po with the biggest C rating as this can handle your needs in this case. . POWER and a cooler Li-Po
So in conclusion
if buying any Li-Po or Li-Fe in soft case or hard case ( model car ) get the best you can afford in C rating the Mah is the run time basically so a 2000mah runs for 10 minutes then a 4000mah will run for 20 minutes and a 6000mah will run for 30 minutes and the charge time is in effect the same so 2000mah is around an hour and 6000mah is around say 2hr charge time that's the draw back and the C rating well that's the punch or stamina like a stallion and a pony or enigizer bunny more staying power LOL

Hope that helps

Oh yea one last thing invest in one of these it tells you the state of your indavadual cell in the pack so if you have say a 6cell pack it can see each cells voltage as can be seen on the left of the picture numbered 1 to 6 to indicate the cell in question a led indicate the cell number

goBulawayo · « **Reply #19 on:** May 26, 2013, 07:30:42 pm »

Brilliant, thanks Gazza -

I ran the battery in the perkasa today got about 10-15 minutes mostly at full or near full speed, charged it at the marina and it got to just over 2200mah as it used to - Ran it again got more like 10 min out of it, again at full speed - Now I won't be using it for 2/3 weeks I take it I need to storage charge it tonight/tomorrow?

many thanks for the help guys

Wayne

Gazza · « **Reply #20 on:** May 26, 2013, 08:00:52 pm »

Wait till there cool again and say a 10 minute charge store away and they will be fine

They when you come to use again just charge as my above post

essex2visuvesi · « **Reply #21 on:** May 27, 2013, 05:55:22 am »

A brilliant well written post there Gazza, glad you stayed

To follow on from that post a little not re charging
A good quality charger will improve run times and the battery life. Some of the Chinese clone chargers are imprecise and this can effect battery life and runtimes.
A good entry level charger is the iMax B6*
http://hobbyking.com/hobbyking/store/__6478__IMAX_B6_AC_Charger_Discharger_1_6_Cells_GENUINE_.html
This will suffice for pretty much all your charging needs as it can handle Pb, NiCd, Nimh, LiPo and LiFe batteries (I have even charged a full sized car battery on it)

*Other chargers by other manufacturers and resellers are available

goBulawayo · « **Reply #22 on:** May 27, 2013, 06:21:04 am »

Hi essex2visuvesi, the imax B6 is the charger I have any idea how to tell if its a clone or the genuine one?

Regards

Wayne

Gazza · « **Reply #23 on:** May 27, 2013, 10:12:18 am »

Well as I Fly planes a lot and waiting for the cells to charge is a pain so I got one of these
If you are going to use your boat for a day and not got many battery's then this is what you need with this baby I can fly . . chat .. have a coffee and still have battery's waiting for me

I can Charge 4 battery's of any configuration NiCad's- NiMh – LiPo- Pb etc. well worth it

and to help charge I use one of these its a car jump start pack with built in inverter and its own 12v 40ah battery

essex2visuvesi · « **Reply #24 on:** May 27, 2013, 10:17:50 am »

Quick check is the hologram sticker on the back

otherwise this is a side by side comparison videohttp://www.youtube.com/watch?v=kziSFSQvxr4

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Author Topic: Issue charging an 11.1v Lipo (Read 5415 times)