Lipos

[Garry Pollard]

Hi Lads

A bit of help required. Just bought a couple of lipos, Loong max Tipple 4s 20c 4000mah. These are stated as 5C. How fast cant they be charged? and how fast do you recomend them to be charged

Thanks

Garry

[Bruce Richards]

Theoretically you can charge them in 12 minutes but you would need a charger capable of charging at 20A and 350W. I would recommend charging at 1C (4A) for an hour.

[Tim Mackey]

I have charged some 2s packs of these at the full 10A ( 2000mahr packs ) and they seemed fine...but Bruce has hit the sharp wire thing right on its flattened head - IE: unless you have the charger capable of doing 5C you are stuck at lower charge rates

Edited By Timbo - Administrator on 27/11/2009 21:09:46

[Dave Bran]

Sorry, but explain to me the logic in buying 5C rated batteries and then only ever using 1C charge rate as per ordinary (and cheaper) cells................No, I thought not.............................

 

I trialled these cells as soon as they became available by buying some of the small sizes (so nothing to lose) and of course applying proper precautions to the charge process.

 

I ramped up the charge rate from 1C in steps to the full 5C.

 

So far no issues at all, not the slightest sign of stress.

 

I have since transferred all my purchases to this type.

 

As a precautionary measure I charge at 1C for the first charge and whenever there is no reason for faster,  but regularly run at 3C when out purely because this is fast enough for my purposes most of the time.  I'm in the "lots of smaller" rather than "a very few larger" camp, since I don't tend to fly long duration anyway.

 

In principle, I suspect most people would only need the higher charge rates while out at the field/event?

 

As Bruce says though, you are far more likely to be limited by your charger.

[Garry Pollard]

Thanks for the comments lads. Wasnt sure which way to jump, but do now. I normally charge at 1C and have a good enough stock of lipos to continue doing that, and in any case I dont think I have a charger which will charge them at 5C

To go to your point Dave. The reason they were bought at 5C was because the company who supply them seem to have gone onto 5C lipos now and are very cheap compared with other suppliers. The price I paid was under £70 for two 4s 4000mah 5C lipos and that included postage, so I feel my logic in buying these explains itself

Thanks lads

Garry

[Tim Mackey]

And I'll bet a few bob it was Giant Cod huh

I too found the price of them ( Tipple ) was very comparable to older 1xC charge rate packs, and bought mine for the same reason...its all he had !

[nasa_steve]

Posted by Dave Bran on 27/11/2009 18:50:31:

Sorry, but explain to me the logic in buying 5C rated batteries and then only ever using 1C charge rate as per ordinary (and cheaper) cells................No, I thought not.............................

 .

 

 well the logic goes like this the 5c cells will have a much longer service life than the 1c cells we've been moaning for the past 5 years about the longevity of cells and the fact that some if used near their c rating have only lasted for as little as 20 cycles. so the manufacturers have answered this with cells that will be capable of lasting in theory much longer than the cells we have been using to date. the side effect to this is cells that are capable of being charged at 5c.

      so the question is do you want 1c or 5c cells????

steve

[Garry Pollard]

You would win your bet Timbo, the only problem that he runs out of stock very fast, and at that price I am not supprised. Seems they have changed over all stock to 5C

garry

[Dave Bran]

Time passes, products improve.

 

Since transferring all my purchases to Loong-Max when they first became available, I have despite lots and lots of strenuous use only had one cell fail capacity, very recently, and a cell that was 18 months old at least, and had been pushed very hard for lots of cycles.

 

I have pulled the leads off a couple, my own stupid fault, but not helped by the stiff wiring used on the short balance lead - now improved by use of flexible silicon insulation on the later ones.

 

Garry, I was not questioning the purchase, but the well meaning but seemingly blanket advice to charge a 5C cell at only 1C as a routine, as I believe its unnecessary to hamper yourself with long charge times on the Tipple 5C cells in the belief that you are doing the cells good. If you have the time, fine, if you don't, well it seems to me from my experiences anyway that there is no penalty lurking to strike.

 

Head above parapet, please knock.........but I do have over 60 Loong-Max 1C and over 20 Tipple type 5C in use now, being used several times weekly, then maybe depending on size being left for a week plus, then used several times in a day, several times a week again. I do not treat cells lightly.

 

I don't believe GC have changed their stock over per se as yet, it's just their batch purchase process or more likely the factory batch production in action.

 

By contrast, my JP Twister cells (pale green sleeved ones) have been MUCH less reliable ( I have 25 plus of them left, too, though their numbers are dwindling as I will not be buying any more).

[Garry Pollard]

Hi Dave

I must say old habits take a long time to change, and I have been charging at 1C for so long it becomes second nature, but as I buy more 5C lipos this will change. 80 lipos is a fair amount to own, how many models have you and how many flights a week do you manage. When I have a session I normally get in 12 to 14 flights but due to a member of this forum I am able to charge up at the field with a genny powering 2 chargers.

Thanks for the info

Garry

[Dusty]

I got 2 of the 5s packs 20c from GC, wow they rated 20c but pushing some mega power!

 

model- Sebart sukhoi 50

 

motor: dymond 5054

 

esc: turnigy 80A plush using sperate 8A Ubec

 

prop: 16x10

 

The watts were peaking at 1200 and drawing 50 amps, nothing is HOT, 6s power for a 5s setup... even changing throttle inputs at 40-50% batt cap the current etc is holding as good as a fresh charged batt (charged normaly not at 5c)...

 

VFM!

 

Dymond motor

 

tried on 6s put amp were high meaning would have to prop down making it not practical for the model but keeping the torque with a bigger prop using 5s is a bonus keeping me lighter for my AUW but the power is awesome!!

[Dave Bran]

Posted by Garry Pollard on 28/11/2009 20:39:57:

Hi Dave

I must say old habits take a long time to change, and I have been charging at 1C for so long it becomes second nature, but as I buy more 5C lipos this will change. 80 lipos is a fair amount to own, how many models have you and how many flights a week do you manage. When I have a session I normally get in 12 to 14 flights but due to a member of this forum I am able to charge up at the field with a genny powering 2 chargers.

Thanks for the info

Garry

 

 You would not believe how many...........planes and helis........ and I also own or maintain around 30 cars/buggies/truggies and four boats.  All models are gear fitted and useable (Not counting three planes being built currently, a Dynamic Soarer based on modified commercial EPP cores but rest OD, an OD fast EP pusher delta wing, and a Beaufighter)

 

Many are quite small (suddenly remembers another 7 micro planes and four micro Helis and three Silverlit stingrays!!).

 

I design my own as well as I like the unusual and the unlikely, for example I have a hybrid MPX Fox with a wing from a "Fik" kids chuck glider, quite powerful EP............flies well!!!  An OD Canard, too.

 

I run an after school RC club twice weekly (I'm not a teacher, BTW), and fly myself for my own pleasure on average three times week on top of school club days. Since I "do" Slope and Helis and Planes, only wet or other extreme discomfort ultimately stops me.......and with the school connection, there are always the two halls out of school hours!!!...............number of flights???....NO idea!!! I did manage nine straight days when I flew during this summer.

 

For at least half of every week I am only ten mins drive from one of my (two) power flying clubs, so I can have a.m and p.m sessions with differing carfuls if I want.............

 

I don't usually charge at the field, but the higher C rating cells come in handy some lunchtimes!!  I carry a lead-acid car battery.

[nigel sheffield]

I have 3 tipples and they seem very good 2 800mah 2 cell 1 1000mah 2 cell, I fly them i esky heli and 2m powered glider and charge at 2c generaly, but after gliding i paralel charge them to save messing about, but yesterday one cell wasnot connected properly and took no charge untill I pushed it in accidentaly after realising balance charge was strugling and so I basically connected an 3.77v charged cell to two paraleled cell charged at  4.2v and then the balance started working better, at which point I thought better unplug everything and check what was going on. the cells were way out oof balance the worst being the one that was not plugged in, it was at 3.98v and 4.2v and i thought it looked slightly swelled, but after leaving over night in the garage and carefully balance charging the next day all the batteries seem fine so I think these cells can stand some abuse, I wonder how many amps went into the cell to get it from 3.77 to 3.98v in the space of about 10 seconds  it took me to realize and unplug them?

[Tom Foreman]

Dusty, you sure that wasn't a 6s1p pack, 1200W out of a 5s1p pack would be pulling nearer 60A with very little voltage sag, if any. If its true I'm going to have to get me some of them packs!

 

Tom

[nigel sheffield]

Just though I'd share my further experience with loongmax tipples, made a huge mistake today first time ever I blame it on being overtired as not had much sleep for about 3 weeks. I pluged 3 loongmax tipples and 1 turnigy nano 2 cells in paralell total mah 3800mah and set to charge at 3amps. went back a bit later to check and cells were at 4.56v each, charger was still set at 3cell a123 and was still putting in 3amps! I imediately stopped charging and set about discharging them, however the cells were stone cold no swelling had occured and still work perfectly, had these been normal lipos there would have been a fire!

These lipos seem to be much more stable then the old ones and thank god they are!

another lesson learnt, don't charge lipos when overtired! and check check check settings!

 

[Andrew Smith 5]

 am still a bit confused say  i have a 2200 3s lipo that will charge at 2c do i enter 4400 in the capacity and leave at 11.1v instead of 2200 to charge at 1c. And will the charger shut off when pack is charged/full at 2200. charger I use is ansman deluxe

 

Andy

[Garry Pollard]

That is how I read it Andrew but I still charge at 1c as Timbo suggested. He knows more about it than I do therefore I take notice of what he advises. There are a lot of lipos that you can charge at 5c but only if your charger will give out enough, and most wont. You ask if the charger will cut out when charging at 2c. Yes it will

Garry

[Andrew Smith 5]

Used lipos for quite a few years all 3s 11.1 just different capacties so to clarify to charge at 2c you would double the capacity, 3c triple the capacity but voltage the same 11.1v and the charger knocks off when full and not the capacity you entered, final point is the capacity you enter  actually is how fast it puts the charge in and not capacity of the pack?

 I have never tried it and probably wont as people said can reduce pack life.

[Stephen Grigg]

Little confused here.I charge with an Ultimat 16,1 battery at a time.On a 3S 2200, ordinary battery Overland I charge at 2.2amps.Normally takes over an hour,is this correct and where does the 2c rating come from in comparison.

[Andrew Smith 5]

Thats same battery im using and thats what i charge at about same time too. hopefully we will figure it out soon.

[Frank Skilbeck]

Posted by Andrew Smith 5 on 10/01/2011 22:30:53:

Used lipos for quite a few years all 3s 11.1 just different capacties so to clarify to charge at 2c you would double the capacity, 3c triple the capacity but voltage the same 11.1v and the charger knocks off when full and not the capacity you entered, final point is the capacity you enter  actually is how fast it puts the charge in and not capacity of the pack?

 I have never tried it and probably wont as people said can reduce pack life.

 Andrew there are a couple of types of chargers on the market, some ask you to enter the battery capacity and others ask you to put in the charge rate you want. I have had both, the older one was the one that you entered the battery capacity and it would then charge at 1C until the battery was either fully charged or it cut off when it reached the total mah, this was like a safety feature of that charger. In theory if you had a 1,000 mah battery rated for charging at 2C you could enter 2,000 mah capacity and it would then charge it up at 2,000 ma until it was full, it would have been like putting a half empty 2,000 mah pack on charge. The earlier lipo chemistry or manufacturing method meant that trying to charge at more than 1C would cause a reduction in cell life, but the technology has improved (and they've got cheaper) so as long as you stay below the manufacturers recommendations you should have no problems.

[Stephen Grigg]

Hope so Andrew

[Pete B]

Yes, that's right, Stephen. To charge a 2200mah battery at 1C, you charge at 2.2A. This has been the norm for most Li-Po's until recently since batteries capable of being charged at a faster rate than 1C have become available. If the battery is capable of taking a higher charge rate, it will be clearly marked with the C rating.

In this example, to charge at 2C rate, you'd set the charger to 4.4A.

This is why some people are querying the 5C rate - not because it is too fast - but more because many people will not have a charger capable of 5 x 2.2A i.e 11A.

I have an Accucell 6 which has a maximum charge rate of 5A, so I wouldn't be able to charge that pack at more than 2C.

 

Pete

[Bravedan]

Word of caution here.

 

 (I have loads of Tipple LiPos of various sizes, from when they first became available, and I do now really mean LOADS, go way back to my previous posts from Nov 2009 and imagine the time delay effect!!).

 

Most LiPo capable chargers I have ever come into contact with, right from the earliest days, and that's a LOT now too, have had effectively three "settings":-

 

1. The cell count (1S, 2S, 3S, etc) if in manual mode or they pick this up from the balancing lead automatically, this of course being the nominal voltage of the pack  (3.7v, 7.4v, 11.1v, etc)

 

2. The Cell capacity measured in mAh (examples.......300mAh, 800mAh, 2300mAh, 3300mAh). This with the stated "C" rating gives the normal max current to be allowed to flow. (examples 2300mAh is 2.3 A for an hour for 1C, 4.6A for 30 mins for 2C, 800mAh is 0.8A for an hour for 1C, 1.6A for 30 mins for 2C, 3.2A for 4C)

 

3. The maximum current that you are going the allow the charger to flow into the battery at any time if it can (Examples..........0.5A, 1.5A, 5A, etc).

 

 

Now for some personal views based on that experience............

 

1. If your charger does not balance (or you are, for reasons best known to yourself, running without the balance in use) then charging at higher C rates is inadvisable. The charger, without the balance lead to tell individual cells voltages, will not be able to measure, so will work on the overall voltage alone, obviously less accurately, as for example one cell could be low, the charger possibly trying to force more into the others to compensate.

 

2. I have not met the charger type that blurs max current applied with capacity, and to be honest, I don't want to!!!

 

3. If your charger has capacity AND current settings, DON'T set the capacity up above the stated pack level!!!!

 

4. From considerable experience in use, Tipple "5C" batteries are robustly made, deliver high current rates, and give good service.   I usually charge my Tipples as a routine to approx 3C, purely because this is fast enough for me, only using 5C when in a hurry.  Yes, over time and a lot of use I have "lost" a very very few Tipples, but at a rate far less than the previous Loong-Max from the same manufacturer, and for their day THEY were in turn amongst the best.

 

[Andrew Smith 5]

Thanks for the advice