Discussion - Bloating Ewatts Li Poly cells from Taiwa

[Flying Fritz]

I have recently purchased 3 different cells for Taiwa in Australia. All have been charged on a Mega charger via a Mega balancer. All are showing signs of bloating.
Tong tests show all within 20c conditions.
I had to resend the email 3 times before I got a reply and the first one indicated they had sent information to their "technicans" and a second suggested I contact a dealer they nominated. The dealer indicated he had similar problems with the product and he sells them but no longer uses them.
His contact with them was "operator error" and we are not realy intersted in fixing the problem.
Has any one had a similar problem with dealers and apart from not dealing with them does anyone have a suggestion on how to get their attention?

[Kahnx]

I have heard similar and repeated reports about Ewatts batteries - I certainly wont be buying any.

Kahn

[ben_fry2003]

Hi,

I have had good experiences with Taiwa (wattsuprc.com.au), I have an eWatts lipo pack 2s 7.4v 800Mah I use with my eSky lama heli. I have charged it with the esky balancing charger 4/5 times without any performance loss in flight or puffing/heating during charging.

Are you sure the balancing connector on the battery is compatible with the balancing socket on your Mega balanced? This different wiring of the plug from the battery and the balancing socket could be causing overcharging of the individual cells which would causing puffing of the packs. It is unusual to find so many failed packs from a vendor (non ebay seller anyway).

I notice there are a number of balancer adaptors cables on the wattsuprc site and I have seen a few discussions on rcgroups on this issue.

Usual dislclaimer, I am not affiliated with wattsuprc but I have purchased from them 3 or 4 times without any problems.

Cheers,
Ben

[pldaniels]

Hi guys,

As a reseller of lipo packs, I can tell you now that there was indeed a batch of cells that came out of some factories between December and March which suffered bloating - a lot of brands were affected (including my own). The actual cause was tracked down to be due to excessive moisture in the process causing more gas than usual to build up in the cells.

Your reseller should accept a photo of the bloated cell and provide a replacement (even UnitedHobbies is doing this).

Regards,
Paul.

[ozace]

from my experience with wattsup and battery packs :( you are on your own.

My 6s trex 600 pack lasted 4 gentle cycles (not uncommon in the original combos) .

[Extreme_RC]

Whats the actual charger you are using?? I cannot seem to find it anywhere in a search. It could very well be a charge issue, but until we can actually see what it is you are using there is no way one can give an honest appraisal.

I would be happy to check the charger and packs for you if you send them down.

The two times I have had an obvious bad battery I have replaced it immediately then checked the cells, sent photos to the factory, and had them replaced.

As for Taiwa, well lets just say you are not alone with the response you have recieved, have heard it many times...

[pldaniels]

As Extreme_RC says.... all cell makers can have a bad day - what matters is how they respond to obvious defects that occasionally crop up.

Paul

[WOOSHKA]

I have 3 of these packs 2 are 1000 mah and one is a 1700 mah all three started to swell about 1-2 weeks after i first started using them one of the 1000 mah ones has done it and all i have done is balance charge it and do a motor test run in my gws tiger moth ,
there is also a small thread on archeli with the same complaint , my son has bought some and they have done exactly the same thing ,
I just dont bother with these cheep packs anymore , i just stick with flightpower, polyquest and dont have anymore problems

[Extreme_RC]

There are cost effective and then there are cheap :D There are two main issues as I see it, Firstly, the biggest killer of cheaper cells is over discharging them, Chinese cells are more likely to gas up if you overdischarge them while under a reasonable load.

The Korean cells are more able to take this, doesnt mean they survive it any better, just means they dont gas up under the skin as much. I have done it to test it and the results are exactly as I describe. With that said, gassy cells, IE a cell that you can feel a small amount of air inside the skin are still quite usable unless they have been pushed so far they collapse internally and read 0 volts.

The second big problem is age and how long they have been on the shelf. The company in question has been advertising their 4s1300 packs on special for almost 12 months now, who knows how long the packs have been on the shelf before the sale started!

This is why I make a big point of having small orders arriving every month or two, I am out of 1300 packs right now aswell as 2200, they are due to arrive next week, the last lot arrived mid May. Most distributors cannot do this, they need to buy 20 grands worth of stock and have it on hand.

Whenever ppl start clearing out large inventories of lipos at very low prices you should be wary, is it worth saving 30% on the price of a battery thats almost 12 months old and has a dozen cycles in it before it refuses to hold its voltage under a mild load?? :(

[pldaniels]

Wooshka,

Definately report it to the supplier - it's a (cell) factory defect - cell packers (TP/FP/PQ included, if it happens to them ever) should replace them.

Paul.

[WOOSHKA]

Hi Paul, i havent bothered because of the stories you read about getting warranty on lipo,s and the suplliers seem to always blame them user or the charger i use an e staion bc5 charger or the hyperion balancer as i have learned from experience what some cheep chargers can do.
I would'nt mind if i had abused them if they swelled but the 1700 one did one flight in my slinger and like i said the other 2 are used in a gws piper cub and a tm
Also like Extremerc said they just appear to feel like they have some gas under the skin - they dont look anything like they do when you overcharge them
I have had them for over 12 months now so i dont like my chances of warranty, doesnt worry me to much i don't get stressed that easily, just put it down to experience.
Richard

[pldaniels]

Wooshka,

Agreed, a lot of the time the suppliers will palm off things like that. The main reason I pushed to have them replaced though is because there is a well known factory fault with the cells produced during that period of time (as apposed to being a random fault). I had all the bloaties in my stock replaced along with all the customers who sent me an email/photo of their bloated pack. More weight to the whole situation was/is that even UnitedHobbies is offering a "email + photo" replacement system too.

Good luck :)

Paul.

[pldaniels]

Okay, someone needs to feed me more coffee - I see that your packs are ~12 months old, okay, that's a bit of a different situation, however anything that was purchased January~March (including some packs still sitting on supplier shelves... getting old...) that suffers to bloating should be covered by the factory replacements.

[WOOSHKA]

I may check my receipts - cant hurt to try
Richard

[Flying Fritz]

It would appear the bloating Li poly is quite an issue. I wanted to find out if other people have had a similar experience with both batteries and service from Taiwa.
I currently have far older li polys that were charged via the old system prior to the availability of balancers. They are still going strong. I am also running some cheapies for bidproduct 300ma 15c pulling 4.7 amps static after around 30 cycles and no problems.
The service left a lot to be desired. I had to send the e mail 3 times to get a response and then a big duck shoving exercise to an unsuspecting agent.
I will not be spending any of my money with them from now on.
Paul. I recently purchased one of your new lost model alarms and it has already earned its keep. Try finding a 22 inch model in an avo orchard. We would have walked past it had it not been for the noise.
Thanks for your responses

[Flying Fritz]

Hi Extreme RC
I miss read the thread and had not replied to your question,
Charger is a gold Mega power and uses a 633dl chip It was purchased from efly power
http://shop.eflypower.com/shop/views.asp?hw_id=847
I use it as well as my Schulze 6330 D in combination with a Mega LCB5 balancer.
Would please flick me your web adddress so I can have a peak.
Thanks
Ray

[pldaniels]

Paul. I recently purchased one of your new lost model alarms and it has already earned its keep. Try finding a 22 inch model in an avo orchard. We would have walked past it had it not been for the noise.


That's what I like to hear (and I'm sure you were glad to hear it too :D )

Paul.

[Tweeky]

I'm another that has a puffy ewatts Lipo. I got about 10 charges out of it before it started to puff. I use a balance charger to charge all of my Lipos. I have TP Lipos that have had about 40+ charges and are still going strong. I guess it's the old saying "you get what you pay for".

[Flying Fritz]

The one problem I have with the whole this is that ewatts are not at the cheaper end of the market. The rest of their gear appears to be OK.

[Extreme_RC]

Hi Ray,
The charger you have is one of the family of swallows, and there have been numerous cases of the swallow charger overcharging packs, I measured two badly puffed packs at another importers place, very expensive batteries, and they measured 5v / 4.2v / 5v per cell! charged on a faulty swallow advance. It would appear that the basic sj propo LBC balancer does not stop this from happening.

Of course your charger may be fine and doing what it is supposed to, how many other packs are you currently charging besides these 3 in question?
You can reach me at www.extremerc.com.au.
Mark.

[ben weir]

Hey mark,
as you know i use swallow ac/dc charger and lbc6 balancer.what should the balance cells read when charge is finished?

[Extreme_RC]

Charged cells are 4.2v Ben, from memory the tolerance is up to 4.25v per cell, but most of the good chargers out there will not exceed 4.21v per cell, and the hyperion chargers usually stop at 4.19v.

The DN charger stops at 4.21v max on each cell and they settle to 4.19-4.2v, but then it has 4 chargers built in so it is not a serial balancer burning off power like all these external balancers are (mine included on the EOS1210i I use for the bigger stuff)

Your charger is working correctly though right? There are thousands of swallows out there and those 5 or 6 cell balancers, and not a huge number of reported failures, but there are enough failures for us to know about them. One guy at my club has had 2 swallow advance chargers pack up on him in 12 months. Others have been using the same charger for 18 months.

[ben weir]

Mark,
My batts all balance vey well and all cells finish evenly well within the range you
just described.I just seem to here more about chargers failing.Sorry for cutting in on your thread Ray,when it come to batterys and the like Mark is the go to man for all your questions.

Cheers Ben

[skyfox]

I deal with taiwa quite a bit, and they provided excellent service. (i've not returned anything yet).
I have 2 of the 3S 2200mah packs, 1 has puffed a little - like its just got a little gas under the top, the other has none. My friend who got 2 at the same time as me also has this issue. In operation, they seem to have no change in internal resistance or capacity (yet). Actually they are very powerful packs in use.
I have not yet reported the puffing this to taiwa. My father has one of the 1300mah packs, which puffed up so much it wont fit in his f-16. Another mate had a pack puff up before use?

I'll contact taiwa to see what they have to say.

I have recently lost a p-38 from cheap ESC's. I'm over saving $20 on a plane. From this experience I guess I'll have to use more expensive batteries in the future too.

PS these packs are still infinitely better than some crap lion brand ones I purchased in Perth about 12 months ago - it lasted about 3 flights.

[sbs]

Hi - I'm new to this forum, EP helicopters and lipos. Reasonable experience on planes.

I've got a trex 450 s cf with about 20 hovering flights on it bought from Wattsup, powered by three ewatts 3s 2200 lipos, one with 13 flights, all OK.

However, the DN Power charger I bought packed up within about 5 charges - sent it back to Wattsup and they replaced it with no problem. They also offered to replace the trex 450 s tail drive gear that fell apart before I figured out that the problem was generic and bought a metal drive gear instead. I've found they sometimes don't respond to email, they've been pretty good on the phone (they normally seem to answer after 2pm?).

[Flying Fritz]

Hi mark,
I am currently using Ace power 11.1v 1050ma, a couple of Dual sky 7.4v 620ma
and two cheapies from a company called bid product
http://www.bidproduct.com/part/Product_view_LIPO%20BATTERY_7.html
all have been cycled in the 30's and no sign of bloating.
I a still using the taiwa 1300 11.1v and power seems OK but I am concerned should it fail in flight as it is in a baby hotliner.
Ray

[Extreme_RC]

You can work out the general age of your batteries in question and where they came from by the label thats on them. They originally started selling packs with Electric Power labels on them, then they changed to Ewatts labels that looked similar in red and black text on white.

The factory stopped supplying them late last year so they went to another cheaper factory (so I am told) and that is the current label of black/yellow/white with red text across the middle.

Anything with Electric Power on it is going to be very old, anything with the red and white Ewatts label will be quite old, we all know what the battery experts have said about old lipo's, plenty of info on the forum.

[ben weir]

E Watts battery
Just purchased e watts batt, the new 25c/50c 2200mah pack,and i'm very disapointed with it, it clearly is not as powerful as it is stated on the label.I hate things that are labeled one thing and do another!Seems it might be a ploy by E watts to sell more batteries even though the batteries are still not that cheap :(
Ben

[pldaniels]

Personally speaking, I consider 'burst' ratings to be primarily meaningless on top of the fact that 'C' ratings are entirely baseless and pure pot-luck.

We really need to get a push from manufacturers to provide cell resistance figures (DC and say 1kHz impedence rating), from the internal-resistance figures we can actually make meaningful comparisons. Of course, I doubt they'll ever consider doing that as it takes away their ability to slap on thumb-sucked 'C' ratings.

Paul

[Flying Fritz]

Paul,
I agree with you. A couple of my cheapies up and some times a little beyond the "C" rating and they are surviving. The batteries that started this thread have been used within the "C" rating and are increasing in girth. As you say its pot luck.

Ray

[wiz310]

Maybe an inline resistance choke to slightly below max C rating. there you go Paul.another brilliant idea for ya. :D

[Extreme_RC]

Alot has to do with where the batteries come from too, there are way too many repacking houses in China and even more small offices in large buildings acting as factories/brandnames and selling all manner of products.

While certainly not wanting to talk up my own batteries, I think the last 8 months or so of user feedback can attest to the quality of the cells being used. In fact I can supply cycle life graphs and Ir tests for my cells as my Engineer records all this data for me to ensure consistency with the cells from batch to batch.

[wiz310]

Is there such an animal as a 7.4V 4C2S pack?. would run into about 1300Ma I imagine.

[pldaniels]

wiz310,

Inline current limiting... could be interesting, though difficult to manage effectively, best way would be to hook it into the throttle channel and reduce the throttle until a safe level is reached again. The -hard- part is how to program the unit, though an easier solution is to just release fixed clamp/choke units, ie, 10A, 20A, 50A etc.

Paul.

[wiz310]

Thats what I had in mind as well...... inline choke units slightly below Max c ratings. one would imagine it wouldn't be to hard to incorporate into the top of a lipo..... a protection system for the battery, individually mounted to each battery.

[pldaniels]

Getting off topic here a bit - perhaps we should move this talk to my vendor thread?

While there are already lipo cell protection chips, including current limiting etc, the trouble we face is that we cannot restrict the power directly without causing some bad effects to the receivers/servos/etc. Best method is to rig the limiter to the throttle and pull it down progressively until the load is back under the limit.

Paul.

[wiz310]

Hmmmm..... thinking cap on now. Yup, getting off topic..... consider this new topic moved to your thread now. :D

[rcozstyle]

Hi Guys

I use my emeter and read what static amps my motor is using , then decide on a battery where those amps are within 50-75% of the c rating.

[wiz310]

Nah, to easy and doesn't include a salable item. :D

[Extreme_RC]

Checking static amps is a must, but you have to correlate it with voltage, as amp draw can vary wildly in large or more demanding setups with only .5v increase at the battery.

My own opinion when setting up a system is that the cells must be stable within the 3.4-3.65v range under full load, 3.5v per cell being the ideal load voltage and a very good indication of true C rating. Most good packs will hold 3.4v at 15-16c static, the really good packs will hold 3.6v+ at this level.

These figures are based on a pack thats had a good dozen cycles to settle it, all brand new packs show high voltage for the first couple of cycles, most settle very quickly to their true levels under load. (from my observations only, and what I have seen others report coincides with this).

[tocano]

I also have 2 ewatts lipo, 7.2 volts 2 cell 850 mah and 11.1 volts 3 cell 1000mah. They worked well for few months then I didn't use them for around 6 months with almost full charge.
When I tried to use them after the idle time, they didn't charge and the balancer kept flashing indicating the lipo had problem.
Tried to charge them without balancer at .1A but still didn't work.
They bloated too.

Are ewatts lipo of the same quality with the unitedhobbies?

I don't fly every week. I need lipos that store well.

[bidlynd]

Hey Tocano,

Can you see any markings/numbers on your lipos, you may have to remove the heat shrink wrap. The faulty Unitedhobbies lipos were labelled 7A to 7E.

You shouldn't store your lipos at full charge, try one of Paul Daniels normalisers http://pldaniels.com/rcshop/frame.php?vp=PLD-LN3S-01

[tocano]

Hi bidlynd,

The lipos are ewatts from taiwa.
They look puff. I just read that some people put them in refrigerator to remove the puff. But mine I think have gone beyond that.
The voltage are well beyond 3 volts so they haven't gone too low but no longer charge.

[femur]

gday all had my lama for about 2 months now purchased from tiawa,same thing happened to me the esky charger buned out and the esky battery i was charging at the time puffed,i emailed them they said the would contact their supplier and get back to me, after reading the posts here i dont expect one soon, any sugestions on how to aproach tiawa on this issue.well anyway i borrowed an esky charger from a mate,now he needs it back i bought a swallow acdc charger and lcb-6c balancer none of the plugs suplied with will fit my battery does anyone here now what plug i should be using.i have a mate that got it working for me by cutting some plastic from one of the plugs and moving one of the pins i am still a bit worried about using it like this can anyone help me with this or direct me to a thread or info on the pinouts of this balancer any help apreceiated cheers James

[tocano]

Femur,

the balancer adapter is depend on what lipo you are going to use. If you are going for taiwa lipos then you can by the adapter from :
http://shop.eflypower.com/shop/views.asp?hw_id=1170
I got mine from them but for 5s balancer (charge up to 5s).

If you are going for top of the range lipos like poly quest, hyperion etc then:
http://www.aircraft-world.com/shopdisplayproducts.asp?id=34&cat=battery+%2D+CHARGERS+and+ACCESSORIES
You can also get other type of adaptors from them. Aircraft world is very helpful so you can email them if you have any questions.

[femur]

gday tocano thanks for the info are you using the swallow charger also,i think what my mate did with the leads is fine as the balancer recognises the battery and flashes 1 flash per second i guess if it was wired wrong it would give me the error code 4 flashes per second,the charger starts charging when i start it,should be ok i think just i bit worried that it might be wrong,given that if the leads that my mate modified for meworks he should be able to work one out for another type of battery?? i sort of understand that the battery has 3 pins one for 1 cell one for the other cell and a balance is this right do you now, i think it is, still not sure how they balance and charge would be nice and easy if i could work it out without waiting for my plugs to arrive thanks again James