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-   -   Lithium Poly Thread (https://www.rctech.net/forum/electric-road/48970-lithium-poly-thread.html)

donoman 08-29-2004 08:25 PM

Lithium Poly Thread
 
How many of you guys run LiPo in your cars? Today I bought my first Lithium Poly pack from All Speed.com and I'm anxious to try it. In the store, feeling the weight, man this thing is SO light compared to C-cells we all use. And the packs can handle 30-45A, which is more than enough.

Also reading the instructions, I found this interesting tidbit: "Other than size, there is virtually no limit on the current capabilities of a LiPo battery. The more cells you parallel the more current you can draw. Paralleling multiple series packs increases your capacity."

This is awesome.
I wonder when LiPo's will become the norm in RC cars.

Joe Maxey 08-29-2004 08:34 PM

I have not ran them in my car but I do use a 3 cell pack in my Futaba 3PK and get awsome time on a charge (3-4 hours).

I have seen other use them in touring car but with no success. I really don't know much about them.

donoman 08-29-2004 08:36 PM

One limiting factor might be the charge rate. I've only read that you can charge LiPo's at 3A. Whereas our 3300GP's can charge at 6A.

Smalls 08-29-2004 08:39 PM

Also,

From what I understand they don't "peak" when you charge them, they need to be on a timed charge. I have heard stories of rc plane guys that have exploaded lipolly cells by not paying attention when they were charging them. Tell tale sign they will expload is when the quadruple in size durring charging.


How much are you guys paying for these... The radio use is kinda cool.

kansasracer 08-29-2004 08:48 PM

A guy ran his at our local track and it ran pretty good. He was a shop owner and said that the battery is comparable to "pro" packs (1.18+)

But he only ran it once, and he charged it with a Triton charger that only charged at like 1 amp...

But it looked really fast, he was running a 19 turn and had NO DROP FROM PEAK PUNCH...

But he said the pack cost him 125.00, and he owns a shop....

Coxy 08-29-2004 08:49 PM


Originally posted by Smalls
Also,

From what I understand they don't "peak" when you charge them, they need to be on a timed charge. I have heard stories of rc plane guys that have exploaded lipolly cells by not paying attention when they were charging them. Tell tale sign they will expload is when the quadruple in size durring charging.


How much are you guys paying for these... The radio use is kinda cool.

That use to happen to them but now they have the right charges for them. 3 stage charging systems will keep them safe. what happens at stage 3 is reduced the charge amp so it won't explode on you when it peaks. I think the Triton is the best around for charging them.

Li-Po and B/L, 1/2 hour EP finals baby, now we are talking.

Also about the charge rate, yea you just charge them the night before and they are right to go come race day.

Coxy.

Joe Maxey 08-29-2004 08:57 PM

Smalls I got my radio battery at cheaperbatteries. I think thats the web name. I paid $90.00 for the 3 cell pack and charger.

Kinitix R/C is building 10cell AAA's packs and they are awsome and super light if you would like something a little cheaper. I think Ron is getting close to 13 or 14 volts and a couple of hours of usage.

He can be reach at rcfiles.com just click on the Kinitix banner at the top and he will take care of you.


I am just about to put a 6 cell pack of lipo and a brushless in a mini-t. I hope I don't tear up to much. 26 to 28 volts.

CraigH 08-29-2004 09:08 PM

The pack they guy ran that Kansasracer is refering to is a Tanic Pack. He went .2-.3 tenths a lap faster with the Lipo then his Nimh. Here's the pack he ran Tanic rc car packs .You would only need two packs for the whole night. They can be charged at 5-6amps with the right charger. The Astroflight is a good one if you can find them for sale. The airplane and heli guys are buying them so fast the supplier cant keep up. Lipo is the future... Just wish someone would put out a good brushless to go with them.

Coxy 08-29-2004 09:11 PM

Yes thats right one cell is 3.7 volts so you only need 2 cells.

Coxy.

GundamWZero 08-29-2004 09:11 PM

Hecks yeah Lipo pack are the BOMB!!!!:D I will have to get some for the car though, got them for the electric heli........:nod:

However, I don't think they will be ROAR legal..........:(

kansasracer 08-29-2004 09:13 PM

.2-.3 tenths doesn't sound that much faster until you know that lap times on the carpet are around 9.3

so.2-.3 tenths is significant...just an FYI

BTW...thanks Craig...gonna race again soon?


Originally posted by CraigH
The pack they guy ran that Kansasracer is refering to is a Tanic Pack. He went .2-.3 tenths a lap faster with the Lipo then his Nimh. Here's the pack he ran Tanic rc car packs .You would only need two packs for the whole night. They can be charged at 5-6amps with the right charger. The Astroflight is a good one if you can find them for sale. The airplane and heli guys are buying them so fast the supplier cant keep up. Lipo is the future... Just wish someone would put out a good brushless to go with them.

GundamWZero 08-29-2004 09:14 PM


Originally posted by CraigH
The pack they guy ran that Kansasracer is refering to is a Tanic Pack. He went .2-.3 tenths a lap faster with the Lipo then his Nimh. Here's the pack he ran Tanic rc car packs .You would only need two packs for the whole night. They can be charged at 5-6amps with the right charger. The Astroflight is a good one if you can find them for sale. The airplane and heli guys are buying them so fast the supplier cant keep up. Lipo is the future... Just wish someone would put out a good brushless to go with them.

What? Stick Packs!!!!!!:eek:
oh, no that won't do at all.......we need seperate cells for saddle packs. But they are cheap....:nod:

donoman 08-29-2004 09:58 PM

How many amps are you guys charging your Kokam's? The exact pack I got was the 15C discharge rate 11.1V 2000mAh Kokam. Truth be told, I bought it for my airplane.

But I have read that there are some LiPo's with 8000mAh capacity. That is just damn awesome. I hate the rush to charge batteries at the track.

Potato 08-29-2004 10:24 PM

Re: Lithium Poly Thread
 

Originally posted by donoman

Also reading the instructions, I found this interesting tidbit: "Other than size, there is virtually no limit on the current capabilities of a LiPo battery. The more cells you parallel the more current you can draw. Paralleling multiple series packs increases your capacity."


That's sort of hype, because it's true for any battery. It's not a feature of LiPo batteries only. For example, paralleling 10 3300 mAH cells will give 33000 mAH capacity and 10x the current capability.

donoman 08-29-2004 10:56 PM

Hmm. Paralleling just any battery won't draw the same amount of current between the two batteries, which can lead to one of them getting used quicker than the next depending on the different IR's. I was under the impression that there was some distributive circuitry built into the LiPo packs to avoid this current divider situation.


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