Help! - Battery Holder Melting

shrewdPanther46
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Re: Help! - Battery Holder Melting

Post by shrewdPanther46 »

While I am running the vehicle, the plastic near the springs of the battery case are melting(the side where the negative terminals of the batteries go). So yes, it's connected to the motor. I am 100% sure there is no internal short.
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Re: Help! - Battery Holder Melting

Post by shrewdPanther46 »

Sorry for double posting.
I can post some pics next time we practice because I think we disposed of the ones that were melted.
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Re: Help! - Battery Holder Melting

Post by retired1 »

Your motor must have some markings on it. That will help to determine Its amperage.

For a 550 size motor at 6 volts, you will have about 2.5 amps NO load and up to about 15 amps loaded. Stall amperage can be as much as 125 Amps. If you do not have reasonable gears, you probably are reaching near stall current for a short period of time. Your battery box will not stand that. Your buggy should instantly take off very fast or spin the wheels or not turn (stall). Somewhere in between.

If your wire sizes are small, this will generate heat in the wire and run the load up further.

I have the same battery setup that you do and do not have that problem. My problem is that the poor contacts will regularly not make contact, This required putting some brass inserts in to make sure that it made contact.
Also cut the wire from the battery box and soldered in much larger wire.

If you believe that the steel springs are not carrying the load, but are heating like a toaster, You might want to try cutting some fairly thin 1" wide brass stock (from a big box store) about 1/2" tall and slide that between the adjacent contacts. Should take 4, 2 on each end with no contact between strips.
I have never done this, so do not know what problems that it might cause like burning your motor up.
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Re: Help! - Battery Holder Melting

Post by shrewdPanther46 »

retired1 wrote:Your motor must have some markings on it. That will help to determine Its amperage.

For a 550 size motor at 6 volts, you will have about 2.5 amps NO load and up to about 15 amps loaded. Stall amperage can be as much as 125 Amps. If you do not have reasonable gears, you probably are reaching near stall current for a short period of time. Your battery box will not stand that. Your buggy should instantly take off very fast or spin the wheels or not turn (stall). Somewhere in between.

If your wire sizes are small, this will generate heat in the wire and run the load up further.

I have the same battery setup that you do and do not have that problem. My problem is that the poor contacts will regularly not make contact, This required putting some brass inserts in to make sure that it made contact.
Also cut the wire from the battery box and soldered in much larger wire.

If you believe that the steel springs are not carrying the load, but are heating like a toaster, You might want to try cutting some fairly thin 1" wide brass stock (from a big box store) about 1/2" tall and slide that between the adjacent contacts. Should take 4, 2 on each end with no contact between strips.
I have never done this, so do not know what problems that it might cause like burning your motor up.
I really appreciate how kind and helpful you have been to me. I just have one doubt. Could the motor draw a lot of current from the batteries because the car is too heavy and the vehicle doesn't have enough torque? Do you think that simply gearing lower would be a solution to the issue (or getting a motor with more turns)?
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Re: Help! - Battery Holder Melting

Post by dmis »

Both ideas you mentioned could be possible solutions. A motor draws more current when the motion of the shaft is resisted, and the most when the shaft is stalled so it cannot move. So yes, if the vehicle is too heavy and the motor is stalling, that will cause it to draw too much current.

Small wires will generate heat, and therefore reduce the current to the motor making it less powerful. But if your wires are not what are burning up, too small wires is not your problem. Small wires will have a higher resistance than lower gauge wires, so less current will flow out of the battery and less heat will be generated in the battery.

Another small thing that could help: clean the spring contacts. Dirty contacts will have a higher resistance, causing more power to be dissipated in the battery case than would be if the contacts were clean.

If this issue continues, it may be easier to just buy a pre-made battery pack where internal connections would be sufficient for the rated current and you wouldn't have to worry about this issue.
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Re: Help! - Battery Holder Melting

Post by shrewdPanther46 »

Solved the issue today. Just not enough torque. Everything working well for now... thanks guys!
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Re: Help! - Battery Holder Melting

Post by PotatoBoi »

Help!
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Re: Help! - Battery Holder Melting

Post by Snarknado »

PotatoBoi wrote:Help!
What exactly is the issue?
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Re: Help! - Battery Holder Melting

Post by Almandine »

An easy solution to this problem is to place the battery in water, let the water boil, and power your buggy via steam power.
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Re: Help! - Battery Holder Melting

Post by 35368 »

shrewdPanther46 wrote:When I place my five, 1.2V Nimh in a typical plastic AA battery holder (series), the plastic starts melting. I think this is because the springs in the case can't handle the current from the batteries and that is converted to thermal energy and everything is melting, although I am not really sure. I do know that this is not a result of the typical short-circuiting error. Can anyone please give me a solution to this issue, and any possible battery cases/holders that would work?



Thanks!
I have the same problem!!! my springs on one side get all burnt out. What you do is put squares of foil on the burnt springs then it works perfect. If it doesnt work for you tell me there are other solutions

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