My Lunchbox Has A 14.4v ESC To Run 2 Batteries? Is There Any Point?

[Grumpy pants]

Hi Chaps,

Excellent forum for gaining knowledge and insight-thank you for your help so far.

Our L.B has a 2 plug ESC so we can run 2 x 7.2 volt batteries at the same time.

The motor is a Tamiya Sport tuned, but is it really going to run any faster with 2 batteries?

In going to try it outside this afternoon, but I would appreciate your experience on this.

Many thanks.

[Falcon#5]

Is it wired in series or parallel?

If it's parallel, you'll get double the run time, but if it's series I'd be wary of trying it for the time being.

Not 100% sure if a Black Can can handle 14.4V?

I'm sure someone will confirm.

[kontemax]

No, normal motors can't handle double voltage.

I think that a Lunchbox with a 14.4 V is insane and not driveable.

I think that a very hot 7.2 motor is insane enough for the Lunchbox so a even faster one is weird in my opinion.

Max

[Percymon]

If its the Traxxas EVX-2 then you can just put a link in the second battery connector to join the black and red wires. Its not clear which battery connector it is so you need to try one, and then try the other of needbe.

Don't run a Tamiya motor on twin batteries unless they are wired in parallel - that is, still 7.2V but double capacity.

Running two packs in parallel for longer run time is probably going to ruin the drivign experience anyway - all that extra weight won't do the wheelie function or 'handling' any favours. Just run one pack at a time and bridge the other connector if needbe.

[beefmuffin]

based on this picture it looks like it was clearly wired in parallel and therefore (i) used for double battery life and (ii) supplied only 7.2v (or, 8.4v if 7-cell batteries were used... or actually the average of any two mixes of voltage) to the motor which would be fine for a brushed motor. the fact the ESC is designed to handle 14.4v indicates that it was either used previously in a double motor setup (like a clod, with motors wired inversely in series) OR the person who chose the ESC didn't understand how parallel vs series DC circuits work and got the 14.4v ESC unnecessarily. but since the terminals appear to be soldered directly to the ESC i'd bet this ESC was previously used in a double motor setup and re-purposed for the LB.

http://www.tamiyaclu...013203223_3.jpg

[dyahipfakta]

Tbh if it is a traxxas evx. Take it out and sell it they make very good money.

[Grumpy pants]

That's great info, I've attached a photo now.

The 2 batteries plugs just lead off the terminals, it is Mtronics ESC.

[Grumpy pants]

I did think it was odd, I wasn't convinced the motor could handle it or the L.B needed it either.

I've got some spare ESCs so I'll swap them over and either sell this one on or put it the Clod I have sitting waiting for some

Love!

The speed on the reply and information was superb- thank you for taking the time to reply.

[dyahipfakta]

Put it in the clod and replace the 540s with 550s or 600s that's are better suited to the voltage. I put 16.8v through 600 motors and they are fine. That would go amazingly well in a wild dagger or clod.

[mongoose1983]

I know I would not even try to turn on a truck with such set-up!

I remember back in the day the gearbox of my Midnight Pumpkin (which is the very same chassis of the Lunch Box) kind of exploded because I run it with an 8.4 battery. So I had to buy a new set of gears for my truck.

How can I ever forget that purchase took about half the money I had for that summer back in 1993...

[wolfdogstinkus]

@Mongoose, are you sure there wasn't some other problem?, such as plastic bushings in the gearbox or a siezed bearing?

I have seen mymonsterbeetleisbroken's pumpkin running a castle creations brushless system, these trucks are tough, I believe TA-mark runs his with brushless as well, TA-Mark runs everything brushless.

[dyahipfakta]

I run all my tamiya on 8.4 volts some one 9.6 for a giggle lol still no grenade gearboxes

[mongoose1983]

@Mongoose, are you sure there wasn't some other problem?, such as plastic bushings in the gearbox or a siezed bearing?

I have seen mymonsterbeetleisbroken's pumpkin running a castle creations brushless system, these trucks are tough, I believe TA-mark runs his with brushless as well, TA-Mark runs everything brushless.

I was running stock gears, and I remember my cousin handing me his splitfire 8.4v battery pack to give it a try. The thing went berserk and I was smiling, all until I heard a dry crack and the truck stopped stone cold. The main gear stripped four tooth and broke in three parts. I tell you a hard hammer hit over an anvil couldn't have caused any more damages to it!

These gearboxes are my favorites, but after that experience I know I would not fit anything funky to them. And by the way, I'm turning my Pumpkin into a Lunchbox nowadays. I plan to run it a lot, but mostly stock as I don't plan to spend extra on replacements. Just looking for some fun, you know.

[wolfdogstinkus]

were you using the plastic bushings though?

[mongoose1983]

were you using the plastic bushings though?

On that truck I was using bearings only inside the gearbox, and nylon bushings on the axle ends (where the adapters go).

Nowadays I will not use not even one bearing in my truck, only stock nylon bushings.