patternflyer1

My Feedback: (11)

GO BACK TO NIMH ALREADY!!!!!!!!

Obviously your LVC was set too low.
You ruined it, just like many of us have.
It's not the batteries fault.

This being said, anyone had experience with the 5s 5000's?
I'm getting ready to purchase some Flight power 5s 5350's but the Maxamps 5000's are tempting.
But the Flight Power warranty is really good, and I've been flying them for quite some time, so I'm just not sure which way to go.

I will be running them in a pattern plane on a Axi 5330/F3A in a 10s config..

Thanks,

Chris

JAM MaxAmps

patternflyer1, I can only ask that you give us a try at MaxAmps. I can honestly say I think you'll like the results. If you have any questions just ask. You can reach me here, by PM, or by e-mail at [email protected].

Jason

hurricane-fibers

I don't know if anybody else has had any probs with the maxamps lipo's
But I have, I have just ordered 3 more cells (5000).
I called and they won't do anything about the others I just got from them.
I have ran my rigger only twice the third time it just quit out in the middle of the pond,
well I got it back to shore and checked everything out and nothing worked.
Tried new esc , receiver , bec , motor still nothing.
So I hooked the battery up to the charger and nothing. then I noticed the + wire had just fell out.
After calling to order 3 new cells thinking it was just fluke I then decided to take the pack apart to find out what happened.
Well was I in for a shock on all 3 cells the + tabs are off right at the covering for the battery and the tape was burned like it was shorting out so I can't even solder then back up.
Man what a waste of 200 bucks for 2 runs about 5 to 7 minutes long just for testing.
They are sending me 3 new cells and I am worried about them doing the same thing.(witch I have to pay for)
I am running a 24 inch rigger with X431 prop 540 feigao (10L 2498KV) I am only pulling around 40 amps
So if any body wants to buy them from me I will be glad to get rid of them I think I will just go back to Thunder power I have had no probs with there batteries
an I might have to spend a bit more but at least I don't have to worry about the tabs just falling off the cells.
If just touched what was left of the tab sticking out of the cell it just fell off like it was made of ashes it was that fragile
Just my two cents worth

If you would like to see pics of them check out my other post.
http://www.rcuniverse.com/forum/m_62...tm.htm#6288979

JAM MaxAmps

I happento be in Spokane and will check on this in the morning.

Jason
Maxamps
[email protected]
www.maxamps.com

patternflyer1

My Feedback: (11)

After looking at your pics in your other thread, your tabs are sorta copper colored, and silver.. All the tabs I have seen on TP and FP packs are silver. Seems to me like yours may have got hot for some reason. Maybe having to change props because it was too fast with the maxamps pack vs the tp pack had something to do with the pack wiring getting hot. Maybe a short somehow.. The tabs being brittle the way you are describing, leads me to believe it was a short..
Just a thought.
I'd also like to see pics of the solder on the wires.

Have you tried any of the hotter packs besides the maxamps? How about the Fp's or Tp extremes?
The hotter packs will pull more amps than the older Tps.. Therefore why you needed to change the prop..
In my pattern planes, I have to change throttle curves if I am to try a different rated pack.

Don't get me wrong, coulda been a bad solder joint creating heat.

I'm sure if you were to talk directly to Jason, and send him those 3 cells and the wiring, he would be in a better position to tell you what may have happened.

Good luck with your new three.

Chris

JAM MaxAmps

It would be fine to send them to me but the only problem is that he was buying loose cells and making his own packs. Now not know how he's soldering them together, temp, solder, and so on will. It be tuff to determine the problem. I see that heat is an issue with his set-up, otherwise he wouldn't have glued balsa spacers inbetween the cells. It's 6:45 AM right now in Spokane, We'll review this today while I'm out here.


Jason

patternflyer1

My Feedback: (11)

Oh, wow. Well that's a different story. I didn't realize that.

As I said, looks to me like a short..

Chris

hurricane-fibers

heat is not issue I put balsa in all my packs just in case I don't like it when anything gets hot.
This setup is in a rigger hydro and there is almost no room and no air flow to cool things down so I like the old saying better to be safe then sorry.
my thunderpower packs get about as warm as a cup of coffee, if you want them to last you dont let them get warm.
An as you can see its right at the joint were the tabs are going into the cells.
In my other thred I say what I am useing to solder them I am an only useing a 30-60 watt soldergun for them when I called the gent told me you guys use a 100 watt for soldering.
if there is any other info you would like just ask and I will let you know.

patternflyer1

My Feedback: (11)

Not trying to argue here, don't take me wrong. Just offering up suggestions as I know how frustrating these things can be.

First you said, there is almost no cooling in your boat.. I see this as a problem in itself. All lipos need airflow. Just like an aircooled motorcycle does.
And you said you older tps got warm as a cup of coffee. Well, with the same setup, your higher c rated packs will get quite a bit hotter than the older packs. Especially with that boat. They look pretty fast!! But actually, they are supposed to get fairly warm. Temps should be in a range of 85 to a 100 for best usage.. But can get much warmer.. So maybe you were ok on heat.. I wasn't there.

As for using a smaller solder gun, I've found that that is not as good for me.. I like the 100w also. You don't have to heat the part you are soldering to for as long. Therefore doing less heat related damage to it. I have actually melted the tab out of a Deans Ultra connector before with a smaller gun. Never even close since switching to the big one. As a total guess this may be where the problem was. It may not appear to have been overheated while soldering, but it may have been. What kind of solder did you use??

Just things to think about. As I say, I'm in no way trying to stir the pot here..

Got any video of that thing????

Chris

JAM MaxAmps

Guys we don't use a solder gun to weld the tabs together. They are welded together with a special machine that places two to three rows of weld across the tab itself. This inturn reduces the heat applied to the tap.


Jason

patternflyer1

My Feedback: (11)

This is the only way I have seen them done by all manufacturers so far. I don't build my own, I leave that up to the pro's..

C

hurricane-fibers

Well as for the lipo my old TP are only half the size of the maxamps one's so the lipo's will not have to work as hard as the TP one's do.
As for the soldering of the tabs it was only on there for less then 3 to 2 seconds I heat and solder the wire first befor I join it to the tabs this way there is almost no heat buildup on the tabs.
I will have video of the rigger this week end and the testing of the new cells.
Also for cooling I have a brushless bike that the lipo is totaly cover and closed in and I push this thing to its limit and the lipo never gets warm and thats because I use a lipo the is 3 times what the amps
the bike needs.
This little sucker will do close to 45 mph I pass cars with it on one of are main streets the speedlimit there is 50km.

JAM MaxAmps

It's real simple, what this all breaks down to is that your putting to much heat to the tab to close to the cell. If your going to continue making your own packs I would suggest placing a heat sink in the form of a forcep (sorry if spelled wrong) across the tab so that you are only soldering the end of the tabs together. This will take the heat into the forcep and not the seal where the tab enters the cell. Like I stated this is only a suggestion, but it has worked for me in the past.

Jason

hurricane-fibers

Ok well to start with, what this boils down to is that you can't admit it when you have a defective product.
It is plane as day to see where the problem with the cells is.
Any body can see it in the pics I posted.
I sure as hell can tell you I never put to much heat to the tabs.
If I did put to much heat to the cells then why is the burn marks inside the cell and why would the nickel tabs just disintegrate?
Do you know what kind of heat it takes to melt nickel (1453 C) thats what it takes to melt it.
Now the melting point of copper is (1083 C) so don't hand me this ----- that I had to much heat from a soldering iron and thats what made them breakdown.
Now there is no way in hell I can get that kind of heat from a 30 to 60 watt soldering iron
A 30 to 60 watt soldering iron produces max around (426.66 C) and that would be a real good one not a cheapy.
You should know more and understand a bit more about metals befor you jump the gun and say what did it.
Hey heres something for you to try, lets see you make a cell do the same thing as what happend to my cells I bet you can't do it with a 30 to 60 watt soldering iron.
If you can then I will eat my words I want to see a video to prove it.

But I guess I don't know how to solder anything, or know what I am doing.
But I work for Ontario Hydro nuclear powerplant making there sensors and monitoring boards witch I solder all day long and I have never had one fail yet.
I also run my own business and have for over 16 years and let me tell you I would never try to find ways to blame the customer that they did something wrong.
I would do some checking and also testing to try and find the problem first, insted of well you did this and you did that and so on.

Hurricane

JAM MaxAmps

You chose to purchase loose cells and make them into full packs yourself. In doing so you take full responsibility for how that pack is constucted and how it performs. We can not be held accountable for any problems that may occur when an individual purchases and decides to try and make their own packs. Our in shop welding system has welded thousands of packs with no trouble and has proven that it is by far the best way to weld the tabs together at this time. You can sit and bad mouth us all you want and say how you work here and do this until your blue in the face. It still, no matter what you do or say comes down to............................

You made this pack yourself and you are the only one who has had this problem. Which means "your" welding system has failed. And with all of the other posts from others here, it's safe to say that everyone agrees with us.


We Cannot Warranty the loose cells. When loose cells are purchased the buyer takes full responsibility at the time of purchase.

If you'd like feel free to sign up at MaxAmps.com and purchase our packs already made. They all come with a 30 day return policy and a 3yr/300 cycle warranty can also be purchased. This way you'll know the pack was made right from the start.

Case Closed

Jason


_____________________________

Jason
MaxAmps Marketing Manager/Tech Support

patternflyer1

My Feedback: (11)

My thinking on this would lead me to believe that if it were the battery at fault, one of the cells would be bad. No possible way would all three have the same problem and you were lucky enough to buy all three. I would think that it was caused by either soldering and too much heat transferred to the cell from the tab, or a wire came loose and shorted all three out.
Anyway, sorry about your luck, hopefully your new cells work out for ya.

Besh wishes.

C

hurricane-fibers

If it was from solding then tell me why just the positvie tabs are the only ones that did this ?
When you build 3 cell pack you solder 2 out of the 3 positive tabs to the negatives.
When didn't they do the same then, they would have had the same amount of heat as all the others?

Old Sloppy

LVC ? What makes you think he has one? I did not read that in his post..(I must have missed that part)

Harry S.

patternflyer1

My Feedback: (11)

Been a while on this thread so I don't remember if I read that. But what's the difference? If he had a low voltage cutoff set wrong, or none at all, it would still drain the battery too much if you ran it too much.. Maybe I'm not clear on what you're asking.

C