HobbyCity Lipo Warranty - Important Information!
 

I originally ordered a pair of Zippy lipos for my E-Revo a few months ago and was very satisfied. I decided to get another pair, and they just arrived today. I tested the voltages of all cells and they were a slightly out of balance (about 20-30mv max), but I figured it was no big deal and they just needed a full charge/balance cycle.

So I charge/balance the packs and then much to my dismay one of the cells only went up to 4.09V, while all the other cells were 4.20V. So I try to cycle them one time on the charger and at the end of the second charge/balance the one cell is still 4.09V

So now I know one of the cells is bad. No big deal, I'll send it back and get a replacement. I fill out the RMA form on the HC site and it spits out an automated RMA number and an address to return the lipo to. But then I took a look at the specific page about lipo warranty info. Here it is:

HobbyKing® Lithium Polymer Battery Warranty Policy.

Due to the complexity and delicate nature of Lithium Polymer Batteries, please note the following points prior to making a claim.

Please keep the following in mind before making a claim;
We check all battery pack voltages prior to shipping. It is a simple process and takes us 3 seconds per pack. Doing so assures us that the battery is fit for use, is within the voltage range and has no shorting.
This process does not remove slightly unbalanced packs.

1) You can only make a claim for 'Under voltage' the same day the parcel arrives and prior to the lipoly pack being charged or cycled. 'Under Voltage' means that 1 or more of the cells in you pack has a voltage lower than 3v per cell. After the battery has been cycled or used, no claim for 'under voltage' can be made.

2) We do not replace burnt batteries. All batteries are checked prior to shipping, if a short on the balance connector was to happen, it would happen prior to shipping. Burnt batteries are also impossible to examine, therefore they are not warranted.

3) We do not warrant crash damage, of any kind. If your pack shows signs of an impact or trauma, we will not replace it.

4) Never disassemble your pack. Regardless of your skill level, expertise or qualifications. We will never replace a disassembled or 'inspected' pack.

5) Rapid Capacity Loss. Should your pack fall well short of it's stated capacity, please indicate to us how you achieved capacity claim. We will test packs for charge and discharge values. Should the battery have severe capacity loss, we will test each cell for maximum and minimum voltage charge as well as I/O. This can indicate to us if the pack has been over-discharged. Packs which are over-discharged will not be replaced.

6) Because of the complexity and nature of these batteries, all packs must be returned to our Hong Kong office. Packs sent to any of our warranty agents, will be rejected.

7) Packs which have a cell voltage difference of less than .245v per cell cannot be replaced. Please balance your packs if your packs appears to be unbalanced.

8) Should you be too concerned about sending the parcel back to us due to safety reasons. We will not warrant the pack. Purchasing any battery from hobbycity.com, constitutes an agreement to this warranty policy.
Each battery brand has it's own warranty time limit. Our standard Lipoly warranty limit is 30 days, unless otherwise stated in the product listing.

I think this is ridiculous. How am I supposed to know there is a bad cell until I charge the pack and see the cell isn't going up to 4.20V?!?!?!? Also, a tolerance of 0.245V difference between cells is unacceptable. And their low cell policy only covers cells below 3V. Again, totally bogus. It's basically impossible to have a lipo pack covered by HC on warranty.

So now I can either send them my pack and have them tell me it's not covered and make me pay shipping both ways, or buy a brand new pack and pay shipping again. I guess that's the price you pay for not dealing with a LHS. I still like the Zippy packs and I know there will be bad packs here and there, but the HC lipo warranty policy leaves a lot to be desired. Looks like my Zippy packs just got a little more expensive...

leave it on the balancer until they are all the same, then charge up again, i had one 5s pack do that to me but it was off .2 to begin with, see if it will come up higher once they are all matched

Hmm... I'm not sure how to do that. I set the charger to balance charge mode and it just ends with the cells still unbalanced. How can I force it to keep balancing? It's an iCharger 106B+ if that is any help.

I have a feeling they do this on a 'sometimes' basis... i received an order once where on one of the packs, the balance lead wasn't even wired properly, and the balance plug was made useless...

is there any other way to check cell voltages without using that balance plug???



sucks to hear bout your pack man - hopefully you get it sorted... i'd just send em an email and ask someone there about it and see what they have to say... if you send it back, and they do find it faulty (that one cell still wont take a full charge) i cant see why they wouldnt replace it for ya man... maybe ask them exactly that?

I'm going to try, but I doubt I'll get anywhere. According to them my pack is fine since the cells are less than 0.245V out of balance. On top of that I charged the pack so that voided any chance of a return.

I'm not upset that I got a bad pack, I still think Zippy are good packs, no product has 100% quality control, especially lipos which are prone to QC issues. It's the HC return policy I'm mad about. And now this puts doubt in my mind, if I do order another pack what if that one is bad? There's no way to know without charging it, but charging it voids any chance of a return. It's a catch 22 situation. When I first placed orders at HC my main worry was that returns would take a long time to ship back and forth. Now I wouldn't care if it took a month or two, I would be happy to have a replacement at all.

is that what is catching you out? i remember having to read that one twice when i was reading it when i returned mine...

I'd tell em their 0.245v rule is BS, and they need to give a damn good explanation as to why it even exists... surely they would have some flexibility in it for certain situations such as yours... and surely when they get the cells there and cannot balance the pack themselves, they would refund it.... right?

Yes, the fact that I cycled the battery and the fact that the cells are less than 0.245V out of balance. Also, they say "under voltage" is only considered for less than 3V.

I admit to being a little compulsive about always balancing my cells, and for me I like to be within 10mV, and hopefully closer to 5mV or less. Am I just way to OCD about that? What is the consensus (or maybe lack of consensus?) on how close cells should be balanced?

OCD = obsessive compulsive??

nah, i would think so - all my cells are within .03 max (mostly all within .01) of each other, and i'd be worried if they were any greater... but only cause i dont know any different...

i'd also like to know everyones general idea on it...

I'm going to try, but here's the problem: "Purchasing any battery from hobbycity.com, constitutes an agreement to this warranty policy." So even though the warranty policy is bogus, you have to agree to it if you want to buy the batteries. Notice how when you check-out you have to click the little box that says "I agree to all terms and conditions" So even though I think the restrictions are ridiculous I have no recourse, since I agreed to them.

ahhhh - i never really actually thought about that one... you'll have to let us know how you go man - i got my fingers crossed for you =)

It's possible that I'm just too picky about the balancing, but I don't think so. With my first pair of Zippy packs I can do a full hard run down to the LVC (3.2V per cell) and the cells would be all within 3-5mA of eachother. We'll have to see what others think is an acceptable range for balancing cells.

you do relize that even IF they warrenty it, you have to pay shipping to them, and the shipping back...

I only had to cover my shipping to them.. They covered it back - but that being said, it certainly wasn't express!

If they dont want to warranty the battery file a credit card dispute . If they want to play hardball you can too.

I would highlight this when you do correspond with them. The pack should heat up after - x time/amps used, shortening the life of the pack. This might be tricky because they stated severe capacity loss, which is open to interpretation.

Good luck.

Dude, sorry to hear of your Lipo misfortune. I hope you get it sorted out.
Do you have a seperate balancer like a "Blinky" or something ?
Try cycling it again but when charging use a much lower amp level going back in ?
I doubt very seriously they can tell weither you cycled your pack if you send it back, just drop the voltage back down to what it came with 3.85 per cell prior to returning.

They only reject cycled packs that are claiming under voltage as I read it. And I do agree, how would they know if it's been cycled?

Yes I do understand that, I've been saying from the start I didn't think they'd warranty it

You guys do make a lot of good points. Like I said before the main thing that gets you is you have to agree to all the terms and warranty requirements by default. I could argue all day with them but in the end I agreed to the terms.

EDIT: I wanted to mention that by my own stupidity I told them (in the RMA form) that I had cycled the battery. I didn't look at the lipo warranty info until after sending the form, again my own fault. But it's like how else was I supposed to prove the pack had a bad cell? It's that catch 22 situation again. Gotta charge to prove the need for a return, but charging voids any chance to return. If I told them I didn't cycle the pack they would ask how do I know there is a bad cell.

Oh well, I'm going to do a few cycles later tonight on lower current and see if I can get the one cell to balance up. I can set my iCharger to the most accurate balancing along with enabling trickle balancing, so it will take a long time but hopefully will give some improvements. I would be happy if it even got within 30mA of the other cells.

It looks like the only chance for a warranty is to check and have a cell under 3 v on the day of delivery. Hobbycity might be overwhelmed with "bad" batteries that are returned that are simply out of balance. This is what appears is wrong with your pack. No amount of cycling will bring it into balance, even a "balancing charge" may not do it.

I don't consider myself to have OCD about cell balance, but when I do balance packs they are within 0-5mv tested over a few hrs. Your pack should just be balanced first, and then test it out to see if anythig is wrong with it. It might just be a mismatched pack or have one cell with a higher self-discharge rate than it's siblings.

I don't have a separate charger and balancer, so when I say "cycling" the pack, it is being balance charged (on the most accurate mode with trickle balancing at the end), then it discharges down to about 3.4V per cell, then the cycle repeats.

I did this 3 times yesterday and actually got the cell to balance. I still think the one cell is always going to drain lower, but I have yet to test the pack. Any of my other packs balance up perfectly with one balance charge, while this pack took 4 cycles on the slowest, most accurate balancing mode. The weird thing is that both the suspected bad cell and good cell have the same internal resistance (2 milliohms when fully charged).

Glad the pack came around for you Jason,hope it holds ?

I had a cell that was pretty low compared the rest on my recent order, I have a seperate balancer and it took 4 hrs for it to level out and it ran fine today. Need to charge it now and see where their all at ?

My friends and I are having problems with the balance plugs being crap on the Turnigy and Flightmax 4s packs. I had to replace 5 so far this last few weeks for friends and 1 of my own. Anyone else having this problem ?

I've had one cell on a 5s pack be lower than the rest as well. I just put the leads of 1M ohm resistor (or any really high value) in the balance tap of the suspect cell and clip my charger leads directly to each resistor lead. Then, I set my charger for 1s and charge at 0.5A. Every 100mAh or so, I stop the charge, let sit for a minute or two, and check the balance. If I have a high cell, I do the same, but discharge instead. This is faster than the measly 100mA balance rate of my balancers, but you have to be very careful not to touch the leads together at any time.

As far as connector quality, I haven't had an issue yet. However, I always make myself some balance connector caps so that dirt/debris doesn't foul up the connector when running.

It'll will be interesting to see how the cell behaves after being discharged. I hope it stays in balance, but I have a feeling it will have the tendency to drain lower than the other cells. Only time will tell.

Our balance tab problems have ben w/brand new unused packs.

I just looked up the Hobby City battery warranty myself.

I was charging my Zippy 5S, 5000mah, 30C batteries for the first time. I had 2 cells come up to 4.13 and the others were full, balance charges. I have it on the blinky now and then I will charge it at a lower amp rate.

Is that to much of a difference?

Personally I think anything more than 10mV difference is too much out of balance. So that would be having most cells at 4.20V and one or more other cells at 4.19V. Even a cell at 4.19V bugs me, and I want all my cells balanced to within 5mV or less.

Of course HC says it's acceptable for cells to be up to 245mV out of balance, which is ridiculous IMO. It would be nice if we could get some official recommendations from lipo manufacturers on what is acceptable as far as cell balancing.

I got the 4.09V cell to go back into balance by putting my charger into the slowest most accurate balance mode. BrianG also suggest just charging the individual cell as a 1s pack using the main charger leads directly into the balance taps of the low cell using some high-value resistors (see his post for more details). Hopefully you'll be able to get your cells back in balance too!

So the balance will be more accurate when balance charging at .5A instead of 5A?

After being on the blinky for a while (4) cells are 4.07 and the 5th. is 4.08. I'll balance charge it tomorrow.

Not sure about "more accurate", but it will balance easier. If you are charging a 5Ah pack at 1C, that's 5A. Most balancers bleed off excess charge at a rate of 100mA-300mA. Normally this is fine for packs that are slightly imabalance. But a highly imbalanced pack may reach 4.2v/cell before the balancer has a chance to do its job.

Look at it another way: You are charging a 4s pack at 5A with a balancer capable of 100mA discharge rate. Let's say one cell is high, which means the balancer will bleed 100mA off the cell as it is getting the 5A charge, which results in a net charge level of 4.9A (5A-0.1A). Depending on how bad the imbalance is, that high cell could exceed 4.2v before the others catch up.

Yeah.

Ok, since you guys are on the lipo topic... heres some "good" info from someone with a "little" lipo experience...

First off, so not expect to have alot of lipo sucess if you are using a stand alone, non charger thru balance (aka blinky). 1st off you have no over charge saftey in place for the individual cells with this balancer, only for the whole pack. So if you have a single cell failure the charger can continue to overcharge the other cells... Puff puff pop. AHHHHHH my house is on fire!!! My beautiful elvis plate collection is gone, why God, why!!!

A charge thru balancer (such as the hyperion lba10) is much safer, as it will interrupt the charge if any 1 cell goes over or under voltage. Still not the best option, but can be had cheap used as it is "old tech", and will work with some of the older lipo chargers. Also, some of the older lipo chargers (astro 109 stands out to me) are a bit weird in how they accomplish the cc/cv charge. A newer charger with all of the bells and whistles is a good investment, IMO. Especially the models that can be updated.

Now an internal balancer charger (suchas the hyperion 6 and 7 series) are the best, as the charge rate will be automatically adjusted if the cells are going well out of balance. I have personally noted this when building mixed cell packs for myself, and then charging them up, if the cells are well out of balance the charger will do .3 amp, regardless of what setting is selected. Plus you get all kinds of nifty info about the cells, and pack, etc.

Also with zippy lipos, you get what you pay for... They are cheap for a reason, so either toss the offending pack, or live with it. I could see complaining if you bought a thunderpower pack, but HC is not making much on these packs, and I can see why their warranty info reads that way.

Heres a little cheap charger that is actually 4 seperate chargers in one box. This charger is good for 2amps max, and charges thru the balance tap. So it will charge the cells individually till they are all full, and thus, balanced. I paid 26 bucks plus shipping and this is a great charger if you have a well out of balance pack, or are putting some cells together that are in various levels of charge.

http://www.hobbycity.com/hobbycity/s...Charge_Capable

Not trying to be a dick, but that is how it is... I have fooled with almost everything out there, and this little charger beats out any stand alone balancer option for up to 4s. You can even run 2 different capacity mah 2s packs on this charger at the same time. Or a 3s and 1s, or 4 1s cells if you like (would have to make a custom adapter to do that).

I see the point you are making but I can't fully agree. Whether it's a $20 Zippy or $300 Polyquest, HC saying that the cells only need to be within 245mV of eachother is too big of a range. I wasn't complaining about the Zippy packs at all, it's the lipo warranty policy I don't like, and that applies to all the packs they carry, from the cheapest to most expensive. Also, I think HC is probably making plenty on the packs, they couldn't sell them so cheap unless they are also buying them cheap. The profit margin may be lower, but they most likely make up for it in volume. Honestly it would be interesting to see the true profit margins on all packs, from the most expensive brands to cheapest budget Zippy.

I still think the Zippy are great packs, it's the HC lipo warranty that is concerning. If anything, the HC warranty has made me more likely to buy Zippy. At least if I get a bad pack (and now given that returns are pretty much out of the question) I'll be out less money than if I ordered a Polyquest. Of course the other choice is to buy at LHS or US online retailers, which I am also seriously considering now.

EDIT: Also wanted to note that it's interesting to see that the last 2 people to review the same packs I got from HC gave them 1 star saying they were really screwed up and one even said one of their cells would only charge to 3.7V. Also interesting to note this comes at a time when HC only have 2 left in stock. Is it possible we got the "bottom of the barrel" so to speak, the ones that they had passed up before for better balanced packs, and now they are moving them out and getting new stock? Who knows? It will be interesting to follow the reviews on these packs (Zippy 2s 5000mah 30C in case you missed it) once they get more in stock.

Not being arguementive but I've found that with my charger/balancer Venom Pro that with a 5amp setting the charger finishes the charge /balance process much faster and with a higher finishing amperage IE 0.4 volts. When I set the charge rate at 2.5amps the charger takes much longer at the last part of the charge by finishing at 0.1 and really is much more thorough at balancing each cell. You can see the way is bleeds off the higher cells voltage while the lower ones are catching up.
What I've elected to start doing is I'll charge my packs at 5amps to acquire 75% charge and then drop the charge voltage down to 2.5 and let it finish that way (I can change charge rate while charging) it finishes more precisely.
I also use my seperate balancer prior and after charging, ben doing that for years and have had great luck with Lipos.

This kinda fun because I was just talking to a relative of mine who lived in Hong Kong about this very subject & they said that the idea of warranty & returns isn`t a concept they understand their.

The battery came back to 4.2, 4.2, 4.2, 4.2, and 4.19.

Awesome! Maybe after a few more discharge and balance/charge cycles it will get all the way up to 4.20. Either way at least it's within 10mV. Now the main thing we need to look out for is how well our suspected problem cells stay in balance with the other cells after putting them through some runs.

This looks more like a to-be-balanced pack rather than a bad cell.

I did experienced a bad cell that can never be charged to 4.2V, it stops at 4.07V while all other cells reaches 4.20V no matter how I charge it. I tried charge the bad cell individually through the balance tag, it maitained 4.07V and generate heat. This is a sign that the cell is destroyed, it refuses to convert electric energy into chemical form, but into heat. You know good lipo never heat up when charged.