ORIGINAL: LBRC

You know if your going to use Lithium Batteries you might a well learn the difference between “Parallel” and “Serries” battery packs as well as Voltage” and Milliamps Per Hour (mAh).

mAh: Or Milliamps Per Hour is simply how much current the battery can deliver over time, a larger number just means a car will run longer, it has nothing whatsoever to do with a motor or circuit boards ability to handle the battery. You could have a 15,000,000mAh battery and as long as the voltage was correct the Micro-T could handle it.

Voltage and Current: Now where talking about what your circuit board and/or motor can handle. To keep it simple the more voltage the faster your motor will turn as long as there is also enough current, but too much voltage and your circuit board will burn up, your motor can also burn up with more voltage than it was meant to handle. Voltage is eclectic potential energy not the energy itself that’s current, an easy visualization would be to think of the water coming out of the end of a hose as the “current” and the speed at which that water is moving as the “voltage.” Try pushing a brick across your driveway with a hose too little water even going very fast (hi voltage, low current) won’t move a heavy brick, even though it would move a lighter block of wood very fast, a lot of water moving very slowly (low voltage, high current) might move the brick but not very fast, you need the right amount of speed and water (voltage and current) to be useful when moving your brick.

Series and Paralle Battery Packs: If I connect two cells (individual batteries) in series negative to positive it will double the voltage but the current will stay the same, so two 3.7 volt 180mAh lithium poly cells in series will give me a 7.4 volt 180mAh LiPo battery pack. If I connect the same two cells in parallel the opposite will happen, it will double the current while the voltage stays the same, so I would get a 3.7volt 360mAh battery pack. The 7.4 volt 180mAh pack would make my car faster but it would not run as long, the 3.7 volt 360mAh pack would not be nearly as fast but would run much longer.

“C” ratings: As in a 10C lithium battery pack, this is an important number to know and will tell you why most cell phone LiPo’s and other low C rating cells don’t work in your Micro-T. “C” x Capacity (mAh) gives you your maximum discharge values. For example a 10C 180mAh battery lithium battery pack can deliver 10 x 180mAh of current without damage or 1.8 amps. Where as 10C 360mAh pack can deliver 3.6 amps of current without damage to itself.

Charging: Lithium batteries have a max charge rate of 1C so a 180mAh pack can be charged safely at no more than 0.18 amps and the 360mAh pack can be charged at no more than 0.36 amps.

Size: If a battery is too big it won’t fit in your car, you have to check it’s actual physical dimensions. Capacity (mAh) and “C” ratings are obviously related to a battery packs size, as a general rule of thumb to keep your self from looking like an idiot you should remember that the greater the “mAh” value and voltage the bigger the battery’s physical size is likely to be. So that a 7.4v 800mAh LiPo battery pack is likely to be four times larger than a 7.4v 200mAh LiPo pack. Another thing to remember is that individual LiPo cells with higher “C” ratings tend to be thicker.

With the best we have available today the largest capacity battery that can be squeezed into the stock Micro-T compartment is a 10C 250mAh LiPo cell pack, thats either a 2s 7.4v 250mAh pack for speed or a 2p 3.7v 500mAh pack for runtime, the 2s 250 you can buy the 2p you would have to make.

Advanced class: If you already understand all or most of the above, especially that bit about moving the brick, you should be able to see why a 7.4v 15C 200mAh cell might be a better all out Micro-T LiPo pack than a 7.4v 10C 250mAh pack, and you would also understand why someone racing a Micro-T on a technical 2xWL RCP track might prefer a 3.7v 2p pack over a 7.4v 2s.

jeep2003 I suggest you save up for a Duratrax Ice, not exactly cheep but it's what you want, on a budget you might look for a used Triton since a lot of Triton 1 owners are switching/upgrading to the Ice or Triton 2. A Piranha would also do but with the 18T I assume you would want or at least eventually want to charge LiPo packs too.

Stock battery: 4.8v 150mAh 4-cell NiMH, made from 4 very good high current 1/3aaa cells, if undamaged thes cells have very good current delivery for 15mm long 1/3AAA's. If you switched to a 3.7volt 2p lithium poly pack you would notice that on a smooth level surface it would be slower (1.1 volts slower to be exact), but since most lithium poly batteries can deliver much more current at any one time on a hill or surface that makes the motor work harder and draw more current the speed difference would be much less noticeable. Also after a few minutes of driving the NiMH pack will start to run down while the 2p pack is still going strong so eventually they will switch and the 2P will be faster.

To sum it up a good 3.7v LiPo pack would give you more torque and longer runtimes but absolute top speed will be slower especially on a smooth level surface during the first two minutes or so of driving.

Lets say you are racing two Micro-T’s on an oval track at WOT (wide open throttle). Off the line the 3.7v 2p LiPo would get the jump because it has more current delivery but the 4.8v NiMH would quickly catch up and pull ahead for the first two to three minutes it would establish a pretty good lead because of it’s higher voltage but after that the 2p would start catch back up as the NiMH started to run out of power (voltage x current) and eventually pass the NiMH. And after 4 or 5 minutes at WOT it would be no contest especially once the NiMH rolled to a stop while the 2p kept going, and going, and going…

If you where to repeat the race uphill the 2p would catch up in a very few seconds, if it was going downhill the NiMH would maintain its faster speed longer.

On a track like this one

the 2p would never fall behind because its greater current delivery allows it to get up to speed quicker and it’s lower voltage would make it much more controlable, only on the long straight would the NiMH start to catch up but in the turns it would quickly fall behind again and after 20 laps even on the straights it would be slower. LoL if the race was for 50 laps it would take a good driver just to finish with a 4.8v 150 or 160mAh NiMH pack.

ORIGINAL: LBRC

The charger was a decent choice but umm how to say it, the battery was not. Problem number one is that it’s 25mm wide, that’s just about 5mm to many. The good news is that with a little work you should be able to very carefully squeeze it in, it has been done before. The other thing is that the small E-Tec packs have a fairly low C rating like around 5 to 8C max if I remember right. So it can work and has been used but there where better choices, available these days. Sorry, but that's not as bad as it might sound, for example it's better than the poor souls who bought some of the low C 150's people where selling, the fit will be the major problem.

Luis1972, take the gear cover off most likely the motor pinion gear is not meshing with the slipper clutch spur gear. If so loosen the motor screws a turn or two and push it forward until the gears mesh but are not tight, then tighten the motor screws back up.