Why did this happen?

[Metallicats33]

okay, i'm still a bit confused about current draw on batteries. Correct me if this is wrong: for lipos it's the ''C'' rating x the mah / 1000 correct? example: my lipo is 4500mah and rated at 28C so that's 4.5 x 28 = 126 amps... right? well this is my problem, how do I find out what a nimh pack can deliver? reason being is I was running a mamba max with a 9000kv motor rated at 100 amps max. the lipo handled it with no problem but my 7cell 4600mah nimh did not deliver the same amount of power and started to smoke I thought maybe the pack was bad so I tried another and I had the same loss of power so I stopped right away. Why did my nimh fry? was the amp draw to high for that battery? is so why? Sorry if any of these questions sound dumb but I'll never learn if I don't ask.

 

[bishiman]

I am no expert on this but I would say that the current draw from that motor was too much for that nimh battery. I would assume that you would need to have a battery with a amp draw that matches the motor draw or has a higher rating. I think it overloaded thta battery and it fried, but I am not positive.

 

[Metallicats33]

that's what i'm assuming also, but how do I know what my Nimh's can deliver? I see nothing on the packs and the net has not ben freindly

 

[bishiman]

I was looking at batterys online and in the ads it said how high of an amp draw it could handle, example a 8.4v nimh 7 cell battery was rated at a max of 40 amps. Did you try looking up the specs on you battery?

 

[Metallicats33]

I was looking at batterys online and in the ads it said how high of an amp draw it could handle, example a 8.4v nimh 7 cell battery was rated at a max of 40 amps. Did you try looking up the specs on you battery?

I did, but I couldn't find anything. I have a duratrax DXT 7cell 4600mah. If the one you were looking at was rated at 40 amps i'm sure mine is somewhere close to that. I bet my system was demanding close to 100 with my setup, that's probably why it got so hot. Side note: the battery is still good! the tab at the back just got so hot it melted the plastic end. I looked over all the cells and didn't see any damage so I charged it and got a full run in my slash today... thank's for the info Bishiman

 

[bishiman]

Not a problem.
When I was young and stupid I put more powerfull motors in electric cars and never upgraded batteries and fried a few. At least your battery still works. I just ordered a 8.4v 4600mah for my Rustler xl-5 because the one that came with it sucks(I did buy it used). Hope to get better results with the new battery.