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-   -   HobbyCity Lipo Warranty - Important Information! (https://www.rc-monster.com/forum/showthread.php?t=23715)

simplechamp 09.27.2009 04:51 AM

Quote:

Originally Posted by lincpimp (Post 323488)
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.

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.

Bondonutz 09.27.2009 07:46 AM

Quote:

Originally Posted by KaztheMinotaur (Post 323484)
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 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.

Erevocanuck 09.27.2009 07:56 AM

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.

KaztheMinotaur 09.27.2009 08:26 AM

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

simplechamp 09.27.2009 10:23 PM

Quote:

Originally Posted by KaztheMinotaur (Post 323528)
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.

himalaya 10.02.2009 09:56 AM

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.


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