Brant-Thanks. If anybody else can also describe their luck tuning with chassis stiffness, please make a post. Fatboy Joe-Thanks.
New Toys. Lithium Polymer Battery (LiPo, LiPoly) Scorpion Charger
I just received my new 3200 mA-h Lithium Polymer Battery from FMAdirect.com
. Here are some basic observations.
The pack consists of two 3200 mA-h cells connected in series and laying one on top of the other. This type of battery requires special Handling and wiring. If you look at the attached photo you can see some of the special wiring. At the right rear of the car is a standard Deans Ultra Plug. This is for Discharge Only not for Charging.
Also at the right rear is a 3 pin connector that goes to the battery. This is used to charge each cell separately so that no overcharge occurs to one cell.
The battery has a harness that connects to the speed control input of the receiver. The speed control then connects to the battery female plug. This circuit is use to prevent over discharge of the battery. The speed control is cutoff before overdischarge can occur. The Orion LiPo cell will probably not come with this feature but will have a better case and higher capacity (4800mA-h).
The battery requires a special charger, of those available at this time the scorpion 1-10 amp charger seems the best for RC due to the ability to fast charge the pack at slightly more than 5 amps.
Generally if you screw up charging with the wrong type of charger or charging mode, the battery explodes and catches fire. I saw a nice picture of this on the Web along with about 30 incident reports. The flame engulfed the entire pit space. For this reason a dedicated charger that can only charge this type of battery is recommended.
This battery is different from Nicads and NiMH in that the two electrodes are laminated together with a polymer film. This means that the battery requires no thick metal cylindrical case to hold the eloctrodes in intimate contact with the conductive film. The battery is thus very light for its capacity. This 3,200 mA-h battery should come in a few ounces lighter than a NiMh. I'll weigh it later.
I will probably remove a foot or so of lead wire from the battery in the future. I need to get some of this big black shrink wrap first. The battery just fits the Losi JRXS tray but it does not slide in easy due to a big bulge from lead wires on the back end of the battery. The case is supposed to be somewhat delicate, so this is not the ideal situation.
Note that I don't actually run these tires and also they are on the wrong side due to recent R&R. Also the four posts that we discussed above are under the four button heads screws attached to the little side ears on the top plate. You can see one of the posts by the receiver.