Charging Circuit?

Delorean Freak · #1 03-07-2004, 01:20 AM

Hey everyone...

I was tinkering with my Xmod today, and I was wondering, would it be possible to implement a charging circuit right into the car, so the batteries wouldn't have to be taken out? I think this'd be a really neat upgrade for anyone to do... I remember reading about someone who did this, but I really don't remember who it was... Also, if this is possible, can it be done with a 5 or 6 cell?

One last thing:

If one were to add a 5th cell, does it have to be AAA, or can it be a AA as well?

Thanks guys,
D Freek

striker289 · #2 03-07-2004, 10:15 AM

ahh u can try but there might be lots of smoke and i dont htink its wise to mix battery types

RC 2NR · #3 03-07-2004, 02:18 PM

I don't know why it's that hard to take the batteries out.

You could put a 3-way switch on the leads going into the ESC. Then you'd wire a connector to the third position which would act as the charging position.

Jshwaa · #4 03-07-2004, 11:38 PM

Quote:

I was tinkering with my Xmod today, and I was wondering, would it be possible to implement a charging circuit right into the car, so the batteries wouldn't have to be taken out? I think this'd be a really neat upgrade for anyone to do... I remember reading about someone who did this, but I really don't remember who it was... Also, if this is possible, can it be done with a 5 or 6 cell?

Applying a charger to your cells without taking them out is very feasible. As a matter of fact, with my setup, it's the way to do it.

As you can see the cells are wired into the car permanently.

I'd imagine if you had a charger the same as mine, from THIS SITE it'd work just as well. This charger charges the cells to a 90% of a specific voltage at about 1A, and then asymtotes the current to virtually 0A as it reaches its full charge. So theoretically, it is impossible to overcharge your cells. Check the site out for more info. I see no reason why this charger wouldn't work for any cell/s.

Another way you could go would be to permanently wire in a plug that you would plug your charger directly into. If installed right, you wouldn't ever have to take your body off unless you needed to do modifications or repairs. I figured that the spring loaded hooks would do the trick, so I went with those.

Delorean Freak · #5 03-10-2004, 12:23 AM

That Xmod scares me... Can you even consider it an Xmod anymore? Anyway, it seems like a good Idea, I just don't really have the know-how to put something like that together... I guess I'll just have to charge the 4 AAA batteries, then the one AA battery separetly... What a waste of time..

Jshwaa · #6 03-10-2004, 08:39 AM

Quote:

Can you even consider it an Xmod anymore?

Considering all there is to CHANGE on an xmod, yes, it is still very much an xmod. The only all-out-changes I made were in the motor and batteries. Everything else was more of an ADDITION rather than changing to something else(i.e. FET's, regulator, thicker wire, etc.)

There are people changing just about ALL of the electronics AND the hardware.....in which case, NO, I wouldn't consider it an xmod anymore. Especially if whatever you do makes you unable to put an xmod body on with the same fit as stock. I mean, if you put my body on, with the hood, you can't even tell the difference. Now that's what you call a sleeper. Shhhh, don't wake him up.

Delorean Freak · #7 03-10-2004, 02:56 PM

That's one way to justify it...

Anyway, that thing is hot dude! What is it's maximum speed?

Jshwaa · #8 03-10-2004, 09:05 PM

I just put my order in, for a tamiya speed checker, today. I have a HobbyTown USA in my neighborhood and I had them order one and they're gonna give me a call when it arrives. I will promptly capture a picture or video of the speed. I'm dying to find out myself.

Delorean Freak · #9 03-11-2004, 03:42 PM

Sweet... Can it compete with a Mini-Z I hope?
Probably a dumb question, it'll probably destroy a Mini in a competition...

Jshwaa · #10 03-11-2004, 05:05 PM

Quote:

Sweet... Can it compete with a Mini-Z I hope?

Uh, yea, it can compete with a mini-z for sure. If it wasn't for the xmods' wheelbase and steering problems, it might even compete with RS4's.

97Supra · #11 03-18-2004, 10:00 PM

Jshwaa so you can charge all four of your cells at the same time without any problems?

Jshwaa · #12 03-18-2004, 10:02 PM

Yea, I have to provide a 25V input to my charger, but I charge the cells at 16.8V and it takes several hours to reach full charge.

jon.jon · #13 03-31-2004, 02:06 PM

Quote:

Originally posted by Jshwaa
Yea, I have to provide a 25V input to my charger, but I charge the cells at 16.8V and it takes several hours to reach full charge.

Im not trying to be rude in no kind of way but why would you want to do this to your Xmod? If you think about it its like having a RC car in the 90s when you didnt have no choice but to wait 5 or 6 hours for your battery to charge, at least then you still could change out your battery pack to give you longer run time in your case you cant. What Im trying to ask is why permanently install batteries to have to wait several hours to play for 15-20 minutes compared to having changable rechargable batteries, 30 min. to 1 hr charge time play for 15-20 min change dead batteries out with fresh ones or charge your dead batteries for 30 min. to 1 hr.for faster charge time longer play time. Like someone recently told me

Quote:

time is of the essence

I may be lost but what are the benefits of this?

striker289 · #14 03-31-2004, 03:08 PM

he isnt planing to drive it alot i think his many abjective is speed but with the lithiums like dta u cant take them off without cuting the zipties so its to much of a hassel to swap

Jshwaa · #15 03-31-2004, 07:18 PM

Quote:

Im not trying to be rude in no kind of way but why would you want to do this to your Xmod?

It's simple really. Because it makes my xmod faster than yours.

Quote:

If you think about it its like having a RC car in the 90s when you didnt have no choice but to wait 5 or 6 hours for your battery to charge, at least then you still could change out your battery pack to give you longer run time in your case you cant.

I'm not sure what you're talking about there. The 90's had li-ions and chargers for them as well. And the decade we fall in doesn't change the fact that charge time depends on the rate of current flow that you induce on the cells for a given period of time. I built my charger myself and the budget is what determined how fast the charger would charge 4 li-ions. For a $7 li-ion charger, I'm not complaining.

My situation is the case of homemade engineering with wire ties, which might look cheesy and is a pain to physically change cells, but it is very light compared to the stock battery holder. I charge the cells inside the car and my intention has never been to play with my xmod for several hours at a time, more than it's been to just have a kick ass faster-than-fast xmod for not that much money. I mean we're talking about buying $1.75 motors and doing everything yourself, including developing a way to bring more than 9V to the motor without frying electronics. To tell you the truth, if I could go faster, I'd wait 3 hours longer each time. Think about what dragster teams go through. They rebuild whole motors and drive-trains for 3 seconds worth of glory. Don't get me wrong, I'm open to suggestions. Show me a faster way and I'll be on it.