LIPOLY
 

i dont know much about these, i know there supposed to be dangerouse, i have an ice charger that can charge lipo, will these work with my gtx car speed controler, is there anythiing else i need to know about these? i know they have been using these in planes for a while so maybe you guys can tell me some things about them, are they notorius as people say?

RE: LIPOLY
 

If not charged correctly, i.e. with a charger not specifically designed for Lithium, they can burst into flames and have been known to do so during charging. They are used quite extensively in electric planes but have limitations as to discharge rate so you need to make sure you have a "pack" that can discharge at a great enough rate for your car. You simply order packs that have enough cells wired in series to provide you with the voltage you need, 3.7V/cell. Your speed controller should be able to handle it (assuming the pack provides a voltage in the proper range) as it regulates voltage, it doesn't really know what kind of battery it's connected to. Check out the car forum, I'm sure there are a lot of helpful people there that can give you specific information for your car.

RE: LIPOLY
 

They are safe if you use the right kind of charger and you treat them with respect. They are no more dangerous to be around than a prop spinning at 10000rpms. The key is only charging them at a 1amp/hr. They pack quite a bit of output and they are VERY light for the power they provide which is the main reason they are great for model airplanes. However each cell is sealed in a very thin foil wrapper. What is inside is somewhat pyrophoric and burns VERY hot if it ignites. As long as you dont bang the battery and expose the lithium inside AND you charge them corectly they are pretty doggone safe. You just have to folow the safety recommendations they come with the battery like charging in a container with a lod that can contain the fire IF it should ignite. I have several of them for my foamies and I have had no problems at all. Thats the gist of it, Im sure you will get some more scientific explainations.

I dont know about a car. I would pack it in foam and in a manner that there is no way the foil can be torn open during a rough ride. The gain is the lighter weight, I cant see them being practical for a car unless the weight is critical...

RE: LIPOLY
 

thanks, we have posted in the car forum, and nobody has a straight answer. im using a brushed motor so the discharge rate from what i understand is well within the limits of the lipos, it is a thunderpack 7.4v 4200mah pack that i was looking to get. i race in stock class and these batteries are about 1/2 the weight of the nimh so it would be huge in stock racing. when you say dont bang the battery can you be more specific, if i go over a jump, are they that unstable that i have to worry, what happens if a plane has a bad landing, will that destroy the battery?

RE: LIPOLY
 

The battery cells are individually wrapped in aluminum type foil. Each cell is 3.7 volts. It will tear about as easily as a capri sun fruit drink container. If you tear the foil the battery must immediately be destroyed per the directions if it doesnt ignite. I think you soak it in salt water to "kill" the battery and stop any threat of a chemical reaction. I have dropped mine on the concrete accidentally and they were ok but it didnt land on a corner and dent any part of the calls. I wouldnt use it if you altered the shape of the cell from an impact. Also you can check the battery to see if it is getting hot during charge and use. Mine are always slightly warm but not even close to hot at the end of a flight. When charging they are completely cool to very very slightly warm using a 1 amp charge rate. I have seen one very slightly torn in a crash and it smouldered a little from the tear. Once they ignite they burn fast at about 2000 degrees from what I understand. They will burn through the bed of your truck, its an extremely hot fire. SOme of the thunder power packs can discharge at about 13 amps with a burst of up to 18 amps momentary discharge.