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bphalf8
08-22-2005, 10:09 PM
I ordered 2 nimh sport batteries from united rc and for some reason they have both gone bad on me. One wont charge past 9.6 and the other one actually blew up in my car. Do you think that there is something wrong w/ my mamba25 or did I get faulty batteries? My mamba25 and motor both run cool, but the batteries always run hot. Any ideas?


Thanks, Chris

BitHed
08-23-2005, 02:01 AM
...UNITED could probably address this much better than me but are you using the same size wiring? You dont have a blockage somewhere? And how was the car speed when the batteries were good? Fast? I am thinking that if the motor and esc are cool then the power from the batteries isnt going to where it should and backing up against itself...

...One COULD consider a bad batch of batteries but to have problems with TWO packs at about the same rate of usage makes me feel there might be a bug in your car...

...When you say one 'blew-up' what do yu mean? Fire and smoke and brimstone and melatge? KEWL!! :cool:

plain_simple
08-23-2005, 12:21 PM
i agree with BitHed.. if the pack melted at first charge then it could be a bad batt batch but when you did run them and recharged and everything was ok then there's got to be something wrong with the wiring... thats bad man... check all the wiring and see if you dont have a short-cut of any kind or wires touching each other along the wiring (could easily happend if you used electric tape instead of heatshrink), for the motor to run cool theres got to be something wrong there and i dont think its the ESC

bphalf8
08-25-2005, 01:17 AM
All my wiring looks ok....I did use heatshrink. Talked to the guys from united rc and they jus said to send it in.....bad thing is I threw it away....I did take pictures though :)

UNITED_RC
09-01-2005, 05:07 PM
And we are sending you a free replacement, dont forget to mention that part.

URC

WeatherB
10-03-2005, 03:35 AM
Off topic but I had the same problem with my battery pack... I charged it up and heard some weird ticking coming from one side of the pack so I placed it on the floor and went to take a shower came back and found...

UNITED_RC
10-03-2005, 01:37 PM
That issue is different. Your pack looks like it had a short somewhere in the build process.

I would contact the builder and ask them to replace it.

URC

EphiDelt490
10-03-2005, 02:19 PM
Ouch, yeah what he ^ said ;)...

WeatherB
10-03-2005, 02:49 PM
That issue is different. Your pack looks like it had a short somewhere in the build process.

I would contact the builder and ask them to replace it.

URC

hahah, that would be difficult as I was the builder. :)

Are you certain it was a short? I'm sure I built it correctly. Took many hours too. Worked fine for 4 or 5 charges

Hawk
10-03-2005, 03:10 PM
You are lucky, you could have been carrying it in your pocket like that one guy posted. :cool:

WeatherB
10-03-2005, 03:21 PM
I had it right next to my ear when I was listening for the clicking noises. It got hot enough to actually melt the glue holding the sells together. INSANE! Thank god no damange to my Mini Inferno

DAMN! I thought LiPoly batteries were dangerous. No more crappy cells for me.

UNITED_RC
10-03-2005, 04:10 PM
hahah, that would be difficult as I was the builder. :)

Are you certain it was a short? I'm sure I built it correctly. Took many hours too. Worked fine for 4 or 5 charges

Well, I could not 100% confirm that it was a short from the pics that you have posted, but here is why i "think" that it was a short:

1. The pack did not have a cell that was "blown apart" like the previouse pics (thread starter)

2. It looks like the a tab/cell over-heated and melted the wrap.

I would trash the cells in the pack, and rebuild one from some other cells.

URC

WeatherB
10-03-2005, 04:26 PM
Thanks. I should just purchase a pack from you.

How much is shipping to Canada?

UNITED_RC
10-03-2005, 06:29 PM
Thanks. I should just purchase a pack from you.

How much is shipping to Canada?


For up to (2) packs, $5.00.

URC