MAC-9-

Thanks for those of you who take pity on us newbies. My question is, The manual says to use a 7.2v Ni-Cd battery (on the apache 24), can Iuse an Ni-Mh with 3300 mAh, and is there an mAh that is to powerful that might damage the electronics?

Thanks againin advance.

rcguy1411

i belive it is the voltage that fries the electronics the higher milli amp rating is just more capacity (larger fuel tank ) so you will get longer run time with a 3300 milli amp vs a 1800 milly amp as long as you stay at 7.2 volts

pompebled

Hi Mac,

Better keep all questions related to youe Apache in one thread, to avoid scattering the information.

As the Apache is a RTR, running it with more mAh batteries will increase the runtime and the heat build up in motor and ESC.
You can add brushtab cooling to the motor to keep it cooler and add watercooling to the ESC.

If you run the stock boat on a bigger capacity battery, check frequently if things don't get too hot, once you open the hatch and things smell funny, you've crossed the line.

Regards, Jan.

mfr02

At a given voltage, the motor can only take what it is designed to take in the way of current.  The bigger A/H capacity just lets it take it for longer.  While running, it is dissipating power, which causes heat build-up.  If it can't get rid of this heat, it gets hotter over time, so if it was only intended to run for X minutes before being given the chance to cool down during recharging, the larger capacity MIGHT cause overheating if it runs for X*2 minutes without having a cooling session.

toklat

you need to upgrade the esc

Doc.316

I agree mfr02. Totally. Ni-mi does have higher "internal resistance" which should limit current some...but for example (ie) I have a dumas trojan with 12V dumas motors....non water cooled...(now this is a scale boat but it should work the same)...when running 1200 mah nicads it would run for about 20-30 min and the motors didn't get that hot...(the speed control is a switch so wasn't a problem)...but when I put the 4500 mah packs in...it would run for about 2 hours!...wow I thought I had a good thing going....but the heat did build up in the motors and after about an hour and a half....(or so) of adding fuel to the fire (so to speak) the motors got really hot....

So I personally believe ...you could add the bigger packs...then after the normal run time for the boat you could come in...smoke a cig....look at the "hot chicks" on the beach....or if you have kids and a wife er...do something with them.....and then when things cooled off (lol... or when they heated up) ....go run iit some more..

You would just have to have the boat have some cooling off periods in between runs....

Steve

Ghost in the shell

7.2v is 7.2v, doesn't matter if its from a nickel cadmium battery or a nickel - metal hydride battery. all the higher number on the mah does is increase run time. (a 1500mah battery will run twice as long as a 750mah battery. the main difference between ni-cd and ni-mh packs is the lack of cadmium, which is just a bit toxic.

sunworksco

I went from NiCads to NiMh to Lipos and now to LiFe batteries.
The LiFes are bullet-proof.
Regards,
John