PitNamedGordie

iTrader: (8)

I can answer a few of these for you...

1. Yes. Lipo cells are 3.7 volts.
2. Yes. Each pack has a desigantion 2S (7.4v), 3S (11.1v), 4S (14.8v).
3. They do not need to be discharged.
4. I usually leave them about 75% charged between runs.

I'll let someone else answer the rest. Hope this helps a bit.

Rick Hohwart

We expect them in February. But with shipping and customs delays, it could be as late as March. We have not had much luck in the shipping and customs departments lately

1. Yes and no. If you have two cells that are configured in series, you will get 2x3.7V for 7.4V. This is the 2S designation. But the same two cells could be configured in parallel for 3.7V.
2. Not always. But the manufacturer will disclose the voltage which will tell you the number of cells in terms of ho to charge them.
3. You do not need to discharge them.
4. I would store them with 75% charge although I think they can be stored at full charge for a week with no problems. Just be sure that there is no way the battery can short circuit. I would also store them ourside of your vehicle disconnected from the electronics.
5. The 5000 pack is configured with 4-cells as a 2-cell pack (7.4V). The 2S2P designation means there are 2 sets of cells wired in parallel, and these two sets are wired in series.
6. The should be available in February.
7. The Pulsar 3 is a great charger. That is what I use and what we use for battery testing here at AE. If you are looking for a good combo charger for LiPo and NiMh, I would definitely consider it.

SWTour

iTrader: (9)

scarecrow,

For US - LIPO isn't what is killing 4 cell oval racing - it was CRAP NiMh batteries..and the timing of LIPO.

There are several places now that have adopted the Brushless/Lipo deal somewhat based on what ARCOR had started with their testing (And what we tested as well) using the new SLOWER B/L motors and a cased lipo pack.

Although for the 08 season we've locked into just a single brand of motor/battery for our small series, I hope once the Reedy packs are available, we'll get to do a little testing with them as well and see how they fit into the mix...

Since it appears there WILL be a Reedy3200 pack - if it proves to perform equally to the currently approved battery - it is my hope that the racers would accept it too. ( But, for now we're staying the course with the SINGLE MFG. deal)

yyhayyim

iTrader: (26)

Hi Rick: is it true that your working on a 30C 7.4V pack? Rumors have been circualting that Reedy is developing an optional "Race" Pro Lipo pack of around 5000mah 7.4v and 30C true rating...would you please be so kind to give us the truth on this...

Wild Cherry

Hey Rick ?

I want-a buy those cells !!!!

Rick Hohwart

Because the upgrades to Lipo batteries for R/C cars will be in C rating, not capacity (more capacity is avaialble now, but generally not necessary), we will be looking to increasing the C ratings in the future. There are higher C rating cells availalbe now, but as C-rating goes, up so does the cost.

So for now, 30C will have to wait.

yyhayyim

iTrader: (26)

Hmmmm...OK so we'll use the Reedy 5K 20C for abot a year, and then we'll eventually see a 25C, and in another year, a 30C? Or Maybe you'll just jump straight to a 30C pack?

Immagine: a 7500mah, 7.4V, 30C pack, w/ same dimmensions as Orion?peak racing 4800 packs, so it can still fit my Type R, and all this for just $139.99...its bringing tears to my eyes

Marcos.J

iTrader: (239)

it will bring a tear to my eye if you keep that type r that long

j/k

yyhayyim

iTrader: (26)

team majic e4/type r...same thing

PDM

As you say since the begining cells are in constant evolution, and the evolution have been the C discharge rate. The cells have become bigger and heavier for that but we have 30C (continous) discharge rating cells now. In a 5000mah pack 30C is 150 amp. Well we can weld with less

30C is the standard in model airplanes lipos, now.

What i have noticed is a drop in the price of the other less capable cells.

The 15 and 20C packs are now called light packs and are cheaper.

Rick Hohwart

To be perfectly honest, this is what is going to happen. Unlike with NiMH, the LiPo improvements will be in C rating and at a pretty high rate. So while LiPo does last longer than NiMH, your LiPo could become obsolete before it stops working.

A 20C 5000 is more than enough for any of our current applications.

Rick Hohwart

I should have said that 30C will have to wait for cars. The car market is less willing to spend the money a 30C 5000 battery will command.

And "for cars" means a cased LiPo

yyhayyim

iTrader: (26)

So can ROAR limit the C rating limit if higher C rating packs will give a racer more punch and power than a lower C rating pack? Or should this be kept open and basically every driver pays for what he can afford and pay for performance?

Rick Hohwart

Capacity and C rating limits are nearly impossible to enforce. Even IB4200s are rated at 4200mAh but are actually cloer to 4600mAh. You could limit capacity by actually testing batteries used in competiton, but it is not a practical way to enforce the rules.

I don't how you could enforce the C-rating. C-rating an capacity together determine the packs capabilities. A higher C rated pack may be worse than a lower C rating pack if the capacities vary.

What could be done is to reinstate the maximum battery price limit. Like motors, a "legal" battery might have to be submitted to ROAR and approved with a maximum MSRP of $150.00 (or $90.00 street price). Only these approved batteries would be allowed for competition (assuming they meet all other specifications). This would actually be a pretty good idea!

4wd Racer

iTrader: (8)

When you say your current Lipo could become obsolete before it stops working, I assume you mean in terms of comparison to upcoming future more powerful Lipo's packs, not in necessary terms of performance change from day one or longlivity. Like computers that works forever, right?, lol.

For the same reason an older "800Mhz Pentium 1" still works and is fine for most applications such as word & internet browsing, but is considered obsolete compared to today's 3,000+Mhz computer.

In other words a Lipo 4800/15C pack may be considered "outdated and obsolete" to future Lipo's upgrades, but if it works fine with more than enough power for your current application (i.e. 2wd off-road). It should hold it's end very well against higher end Lipo packs that offers more than usable power that you can ever dream of putting down in off-road.