R/C Batteries

[treegump]

I just received an rc truck that uses a 7.4V battery. I have another truck that uses a 6V battery. Can I use the 6V battery in the 7.4V vehicle?

I know that if I were to use the 7.4 in the 6 vehicle I take the chance of frying the motor and components, but I can’t find the opposite.

Also, I’m purchasing an adapter to use a 5200mah 7.4 battery in the 7.4. It’s the same voltage, so it shouldn’t hurt it, right?

The largest battery was a 7.4v purchased for an RC truck that was a sham (received not the product that I was led to believe). The green is a larger mah 6V for my 6V truck. The blue is the stock 7.4v that came with the sham’s alternative.

 

[ak diesel driver]

I think you'll be fine I run 20v batteries in my 18 volt tools with an adapter made for doing so.

 

[treegump]

But, if you ran the 18v batteries in a 20v tool, do you think it'd still be alright?

 

[Duvall]

You have 2 batteries made from different materials.

The 2 cell lipo is a nominal 7.4 volts. Each cell is 4.2 volts fully charged and 3.0 volts completely discharged
The green pack is probably NiMH (nickel metal hydride) 1.2-1.5 volts fully charged per cell and .9 volts completely discharged

Depending on the electronics in the truck it may not run at all on the 6.0 volt battery. If the internal electronics are designed for lipo cells, it should shut off at a safe lipo voltage that is above the charged voltage of the 6.0 volt pack. It wouldn't run long if at all and it wouldn't be fast because of the current capabilities of the battery. Look at the wire size.
Lipos are sensitive to their respective fully charged and discharged voltages. If they go out of their range, bad things can happen. Typically over discharging will just ruin the battery and it wont charge anymore. Overcharging can have devastating results including serious hot fires. (look up lipo fire on youtube).

I can't exactly tell what cells are in the blue pack. Its 500mAh so its not going to do much either way.


There are also different chargers for Lipos vs Nimh batteries some do both, but not all. Please do some reading on these batteries for your safety and the safety of your family. Improper Lipo charging has been known to burn down garages and houses.

 

[jrsavoie]

Check Nethers Batteries in Ohio. I have been sending him my batteries to be rebuilt. I have not been disappointed yet

 

[Will L.]

On DC (batteries as opposed to AC like your house) yes you can run lower voltage batteries. As the 7.2 looses power while operating the r/c toy, it’s voltage drops. The device electronics will be built to not have damage from too low of voltage. The electric motors simply turn slower so like only pushing the gas pedal 80% instead of 100%.

Like mentioned above, the electronics may not function if power is too low- but it wont damage anything.

 

[treegump]

Here is a closer photo of the blue battery which came with the rc truck. Also, the battery charger for the large limo battery-which i haven’t unwrapped because I didn’t know if I could use the batteries. And also purchased battery charging containers.

 

[treegump]

@Duvall - So...do you think it'd be safe to run my 5200 mah Lipo 7.4V battery in the vehicle that came with the 500mah 7.4V battery? I purchased some Dean plug to JST plug adapters, so I am able to connect the battery to the vehicle. I just don't want to fry anything.

I will keep the 6v's with the 6v truck and the 7.4 with the 7.4 trucks. I will not try cross-using them.

 

[Duvall]

As far as the voltage goes you should have no problems. I don't see how you get a battery that size into anything that uses such a small battery.

The only issue I see is the low voltage cutoff point of the electronics in the truck. Of course its going to take a long time to drain a 5200mAh battery in something that's designed for a 500mAh battery.

 

[Will L.]

Yeah, if you can fit it- wow what a run time.
mah is milli amp hours. So the big one is simply going to operate just over ten times as long.

long run batteries are the key to fun.
When younger kid had the power wheels truck (red chevy of course) and their expensive 6v battery died-out came some plastic with the sawmill and in went the 12v deep cycle tractor battery. Went from put around a couple hours then charge to him drifting and donuts 2-3 hours everyday and only charging once a week! Mama didn’t like seeing her younger one sitting on the hood steering behind his back with a rock on the throttle. Like I told her- I would have stopped him but I couldn’t quit laughing. Better battery = more fun and better skills

 

[treegump]

As soon as I was looking at these cheap RC's, that was the first thing I looked into. The 2 biggest complaints were run time and weak drivetrain parts. There are replacement parts available, and so I started looking up batteries.

I'll let you know how I manage to fit the larger batteries in.