Battery upgrades...???...

Keono · #1 12-17-2006, 11:40 PM

1/3AAA 150MmAH 4.8V.... sound famaliar? it should, it's the Micro-T's battery pack, stock. Here's the thing though... 1/3AAA batteries can go up to 180mAH... the problem is, I have NO IDEA where to get a 180mAH 1/3AAA battery. www.cheapbatterypacks.com doesn't have 'em. nor does anywhere else I look. are they rare? I don't know.

OK, let me run this by you guys. 1/2AAA is a 250mAH (average) if you look at the sides of the Micro T, you could essentially cut a hole in either side of the battery compartment, making room for the 4 cell 1/2AAA 250mAH battery. you could then, easily cover it up with some black electrical tape, or what-have you, to make it "look good".

If you don't care about looks all too much, maybe you could (you being ME) take 2/3AAA 350mAH 4 cell battery and have the battery sticking out the sides a bit. I checked the dimensions, it won't interfere with the tires... but it will be CLOSE... like... 2 or 3 mm space between the battery's and tires. that's with the wire.

so, tell me what you guys think of that idea... maybe we can get these little buggers to run longer than 10 mins.

RCdabbler · #2 12-18-2006, 07:35 PM

More than the dimensions look at the weight that you will be adding also.
I'm not saying it wont work I'm just saying facture the weight in also.

In a vehicle this small weight has a bit more impact on overall vehicle handling.

I'm still waiting to read the reports of 2 celled LI-PO's being used and if the stock electronics can handle them.I suppose someone could make a failsafe for it.Either a simple fuse or a voltage limiting circuit but what is the safe threshold of the stock receiver & ESC & servo units?

Or you could just use a 1 celled high MAH LI-PO battery and have massive runtime but with a reduced voltage/speed.But it would most likely be lighter than stock batteries.

http://www.bphobbies.com/view.asp?id=A0320104

http://www.bphobbies.com/view.asp?id=A2416227

Keono · #3 12-19-2006, 01:01 AM

I've already added ALOT of weights to my micro-t because it weighs too little to get traction on hardwood floors. I have a second body that I totally weighed down. I've added about 1.5 ounces of metal. it's kind of hard to see in the picture, but it's weighed evenly on both sides. you can increase traction one of four ways... change the material of the tires, change the floor, change gravity (lol) or change weight of the car. the weight on the body makes the car get a crapton better traction, and I wanted to add even more weight with the new battery, but it's pointless now that I realize all I'd be doing in increasing the mAH, when I really want to increase the voltage. I had a minor brain fart! anyway, That link you showed me with the 1/4AAA battery size may prove VERY usefull. if I put two of the 6V 80mAH stips in paralell I can get the 6V and a 160mAH I could change the weights back to normal on the body. I'm not sure where I'd stick the two strips of batteries though... I just gotta figure out a way to make the shocks STRONGER... maybe a cut up Bic pen........

hehe, any ideas?

OH! one more thing! I wish I could remember what forum I was on, I did a search on www.altavista.com for "Micro-T Li-Po" and found a forum that people claim to have used a 7.4v li-po battery that's used in helicopters, something like, aero, or something... but it works allegedly, and I didn't see anything about it burning out the reciever/esc.

I wouldn't try it yet though, since a new receiver/esc costs 29 bucks!

RCdabbler · #4 12-19-2006, 05:46 AM

I thought you might like the links.
I looked around on TinyRC for batts but the site is set up way to weird to easily find all the batts they have so I just posted those links.

I've been running mine on the carpet only and it has good enough traction although I'd like foam tires for the carpet which I'm sure will be coming soon.

As more and more info comes out on these trucks we'll know what it can handle.I'd love to have LI-PO's in it running 7.4V and with a longer run time.

potentiality · #5 12-19-2006, 09:52 AM

Quote:

you can increase traction one of four ways... change the material of the tires, change the floor, change gravity (lol) or change weight of the car.

Number 1.

Change the setup of your car. It is still adjustable you know. Adding weight isn't the best way by any means to gain traction.

Keono · #6 12-19-2006, 03:10 PM

adding weight is the ONLY way to gain traction without changing the tire composition (there is no different tire materials available) and there's no way I'm sanding my hardwood floors to get traction for an 80 dollar rc car, lol. and as for changing gravity... well... that's a little beyond my capabilities, ROFL! I read someone's post about putting WD40 on the tires overnight, but that destroys the rubber of the tires, and once a little dust gets to the tires, and it's no longer sticky, I'm back to square one (U_U)... and as for the Micro-T being adjustable... it's really not... the stock pieces are pretty specific as to where stuff goes... sad... sad but true...

dj6666969 · #7 12-25-2006, 03:28 AM

http://www.one18th.com/forums/showthread.php?t=42758

Namuna · #8 12-26-2006, 12:51 AM

The 'aero' you're referring to is probably the Air Hogs "Aero Ace" and it's a biplane, not a helicopter.

It runs on a 130mah Lipo battery and you can actually buy the batteries themselves from IndoorFlyer (they're based in the UK, but shipping is actually very reasonable to the US):
http://www.indoorflyer.co.uk/index.a...&productid=117

Myself, I had previously bought a 5pack bundle of 160mah Lipos that I wanted use on my Bits/ZZs, but they turned out to be too big...But they're actually PERFECT for the Micro-T!

Keono · #9 01-02-2007, 09:42 PM

can someone please explain this diagram to me? I've not made any battery packs before made of lithium ion cells. and the 3,000 degree fire kinda scares me. I would understand if the battery+ and battery - were the only "intake" places, but what is the "commons" soldering point for? I know that the circuit is an auto draw-stop (sort-of) and an auto fill stop so it can't fill more than 7.8v (I think) and no less draw that 6v. But the whole Commons thing totally throws me out of whack. please help?

LBRC · #10 01-03-2007, 02:23 AM

Common, Adjective, belonging to or shared by two or more.

The best safety advice when using lithium’s I can give is to invest in a good hobby class lithium charger, then read the directions and pay attention to what you are doing. For example the Duratrax Ice, or Triton, they come with built in protection circuits.

Over discharging is seldom a problem if you follow two simple directions:
1. When the car starts to slow down stop what you are doing, turn off the car, unplug the battery and charge it.

2. When you are done driving, turn off the car, unplug the battery, charge it, then leave it disconnected until you are ready to use it.

Lithium Do Not’s
Do not continue driving the car with a low battery.
Do not turn of the car, let the battery recover some of its voltage then drain it again.
Do not store the car with the battery connected.
An especially do not leave the car turned on when not in use.

Keono · #11 01-05-2007, 10:10 AM

Thanks LBRC, I appreciate the help. I've been using Li-Po flatpacks for quite some time now in my airplane, and my Mini-T with a brushless motor, but I've always bought the packs. I've never MADE a pack. and that is what I was asking about, is what the "commons" connection point is for on the protection chip. I know what the word, common, means, what I don't understand was why there would be a common connection to the board. why not just keep the batteries in series? or does Li-Po need to charge in parallel? That's what I was asking, I should have been more clear. I simply do not understand why you need to make another common soldering point on the board with the positive of one battery and the negative of another.

LBRC · #12 01-05-2007, 03:24 PM

That type of circuit usually monitors each batteries individual voltage which is why it needs to be connected to each one separately. If either cell's voltage is ever too low or too high it acts like a fuse or switch and turns the pack off, buy opening the output, so that the pack can no longer be charged or discharged.

Keono · #13 01-08-2007, 01:14 AM

oh. damn. that would suck. what a waste of a li-po. I guess if it was operating a more expensive car or something, and you didn't want it to catch fire or something. who-knows. thanks man, you just saved me about 30 bucks in shipping/li-po cells.

FYI www.atomicmods.com is planning on coming out with a chassis in stainless, professional done (not these e-bay hackjobers), real soon. he's already released some professional (and cheap mind you) upper arms for the front/rear and steering arms in stainless. all laser cut and what not. real cool work he's done. cheap too. it's on e-bay at the moment I think.

http://cgi.ebay.com/micro-t-upgrade-...em270075416004

is his link for the steering arms

ONE MORE THING!
I jsut realized... we're all hopping up our Micro-T's with brushless/aluminum/stainless/ and whatnot... here's the thing.
are we all just making micro bullets or what? lol it goes fast enough as it is...
what will happen if it weighs a full pound and a half after all the upgrades and it's going a full 15 MPH into someone's foot? ROFL. anyway, something to think on. I'm still gonna hop mine up BIG time

Clutchbob · #14 01-11-2007, 10:04 PM

The diagram is very misleading. If the black lines represent connections, they would be putting shorts across the cells!!
Many multicell packs include a balance plug. these simply bring out the interconnections between the individual cells. A three cell pack would then have four wires, the outside wires usually being the overall voltage in series and adjacent wires the voltage of the individual cells. A few of the new Lipo chargers can make use of this plug to balance each cell during charging. Manufacturers also make balancing adapters.
Balanced cells are critical in Lipo packs. Repeated use can unbalance cells and can allow for overcharging or overdischarging of an individual cell.
I recommend that if you are building your own batteries that you provide a way to balance in this way. It's very easy to then charge each cell individually, if you don't have a balancer, fully charge each cell with a single cell Lipo charger one at a time every so often. You should do this with a newly built pack before you charge in series the first time as well.
A voltage check will confirm which wires are the individual cells when you're not sure of the plug configuration of a prebuilt pack.
Be carefull building packs, NEVER short cells.

Keono · #15 01-12-2007, 12:51 AM

Shorting cells is an instant mistake. If nothing happens, you're lucky. If you only lose your hand, you're lucky. If your house burns down, well... you shorted a lipo battery. I shorted a lipo battery (fully charged) out of curiosity out on the pavement, and it scortched the pavement. I had LONG lead wires, so the ohm resistance may have made it less, I dont know, and don't want to find out.