PartTime

iTrader: (10)

Yes, the C rating will keep going up too. And they will get less cycles, faster and less stable just like the ni-mh's did. In case some people dont know, round cells last way longer than li-po's, cycle wise (Although playing with these 4200's I have to REALLY recconsider that last statmentand) the chemicals in lipos only last 4 or 5 yrs no matter how you treat them. Evalution I guess ?



I have 3600's at 25c and they do just fine against some smc 5000's. Those have capasity (wheres the spell check when you need it?) and c rating on me. They should end at a higher voltage for any given run. If I cant win with these packs.......It's me. They should have no problem getting me through this season and maybe next's competitively. If not then pick up the hot cell next season and give it a go? They could be as high as 6000 at 40c. On that note where do you think roar will cap the capasity at ?

DK

PartTime

iTrader: (10)

Classic Well put.

DK

rsperson

Roar doesn't need to cap them - the motor will do that. If you are limited at motor, you will just overheat and run slower if you try to over gear for batteries.

It just might get to 20 minute mains.

Uncle Cliffy

iTrader: (8)

Newb alert!

My local club track (indoor carpet) just got going here and I've thought of getting a pan car. Nobody is running them yet, but a couple guys have older cars laying around. I currently have a sedan that I'm in love with, but ever since I raced as a kid in 86, I wanted a 1/12th scale.

I haven't used NIMH much as I'm from the old NiCD days. I have a few LIPO's and so far so good. Really good! There's a big bunch of people racing 18r's at our track, including me so I already have small 2s packs and a Mamba 4200 mini motor in my tool box... All I need is a car and a reciever to try this out.

I guess bottom line for me is I like the idea of trying this as I'm just getting started in the hobby again. It doesn't make sense to me to invest in NIMH cells when everyone I know here is switching to Lipo.

Now saying that, not to derail the thread, but can anybody link me up to a good chassis that would hold a 100 X 31 X 18.5mm lipo?

trailranger

Why change the car to fit the battery? Just fit the battery to the car.

This 2S battery will fit a Linked 4-cell car.
http://www.batteryspace.com/index.as...OD&ProdID=3019

andrewdoherty

iTrader: (49)

This one also fits. Too abd the shipping is 17$. I have one exactly like this and is what I have been using to test 1 cell. I had to rewire it, but tiwasn't taht hard. plus its 25C (or so they say )

http://cgi.ebay.com/GE-power-7-4V-1800mAh-25C-Lipo-Battery-Pack-for-RC-boat_W0QQitemZ260314328764QQcmdZViewItemQQptZRadio _Control_Parts_Accessories?hash=item260314328764&_ trksid=p3286.c0.m14&_trkparms=72:570|66:2|65:12|39 :1|240:1318

Uncle Cliffy

iTrader: (8)

Baattery? Typo on the lipo.

Fred_B

iTrader: (1)

Freezing batteries won't change anything because the manufacturers will just make running changes just like NiMh. Limiting cell approvals to a yearly cycle would help because a lot of us buy one or two LiPo's at the beginning of each season. We'll have to wait for ROAR rules for this to happen.

The motors will continue to develop and get faster and the motor of the week will replace the battery of the week. There's no stopping the development or cost in racing. I spend more on tires, motors, and bodies than batteries (niMh indoors or LiPo outdoors).


For the t-bar guys, Maxamps would probably make a custom saddle pack for you if you talk to them a little. I used Maxamps cells when I tested 1 cell and 2 cell in 12th last year. May not be the cheapest pack but you won't have to rework anything except the connector if you run one.

Tubaboy

iTrader: (9)

Fred,

I believe that next year ROAR will go back to the yearly cycle on battery approvals. This year was an exception to entice companies to get them made and submitted and ready for immediate approval.

Paul

Carl Giordano

iTrader: (32)

Local Racer,

and this is not an attack towards you, but a number of us old timers in the industry get insulted when we hear that "if you care for your nickel metal cells they will last a long time". Who the hell has time to baby sit NiMH...

For the consumer who wants to "race" RC, the current providers of NiMH's are screwing us with crap products as their cells remain the weakest link. On my post above, #153, I just discarded over $1000 worth of NiMH batteries ranging from 3300-4600 (2+ year time period). The fact that I just purchased 4x 4600 packs during the summer and left them "NEW" in the box until November to build and they failed to take a charge is a disgrace. Where's the abuse in that...

When Sanyo left the market, electric racing took a downturn. Overtime, people are getting sick of having to deal with cells that fail or lack in performance unless you "take care of them". Hence the reason why fuel racing has remained popular, off-road is thriving (driving is the equalizer) and Lipo's will rule the electric on-road racing.

The fact that my Lipo wired transmitter still had 11.8v available after sitting since the summer makes life easier to focus on the aspect of racing and all thats fun with this hobby.

I went on the website for these NiMh "providers" (I won't use their name as they are only repackagers and not the manufacturers - so its not right to bash them on this forum) and "some" have a reasonable return policy. So long any cell that fails is returned with a receipt that reflects the pack was purchased within the past 30 days.

So they know that the cells deteriorate over time and will not take a charge if sitting too long at either the distributor and/or the LHS.

With Lipo's you do not have this risk...I wish ROAR's electric committee would resolve the issue for 1/12th scalers so we can be done with NiMH's once and for all. Years ago, we use to race 6-cell 1/12th scale, 4-cell introduced only because 8-minute of run time was the issue. Not to slow the cars down.

IMO: If a 2s 17.5 1/12th scale is too fast for some indoor tracks, than us racers have the option to (i) use a slower motor, (ii) drive within control...and throttle back, or (iii) turn throttle endpoints down to drive at a speed we can control and slowly build up to higher speeds.

Years ago we were forced to have to "throttle drive" to manage our battery power and finish a race. We benefited by learning throttle control and we had reserve power if/when we wanted to make a pass.

R/C racing is becoming like restrictor plate racing....and what's the fun it that....

I still fail to see how Lipo's cost more in the long term. The voltage is monitored at the start of each race, so the need to purchase a higher capacity Lipo to enhance the voltage output over the discharge curve yields marginal benefits. Today's Lipo capacity has enough mah to handle our race periods without a noticeable difference in voltage over the discharge period. Now if ROAR increases a race period to 10 minutes than mah will become an issue.

I know guys using a 1year old Lipo pack in their TC without the need to change it. They all rave about the fact they've not purchase NiMh in over a year. Sounds like they're saving money.

I'm please to hear my local track has taken a position on the use of Lipo's for 1/12th scales. The fact that I will never have to waste a dollar on NiMH's is awesome.

Apex

iTrader: (51)

Is ROAR working on a 1:12 LiPO solution right now?

Also, does anyone know if ROAR has a C rating limit on LiPO's?

SlowerOne

Poor argument, easily disproved by facts...

If people were this responsible, there would not be a single fatality on our roads. People do not buy slower road cars because they can't handle fast cars - fact. People do not know when they are about to lose control, which is why they have accidents when they run out of talent at the wrong time - fact. People do not put a piece of wood under the gas pedal to prevent them from going too fast - fact.

It is almost inconceivable that we would allow 7.4v in this class in Europe. We cannot control the people who will try something ridiculous, run out of talent, and possibly have cars flying through the air. As a responsible European Association, we have to demonstrate that we have a duty of care to our members, otherwise we can be sued.

As any psychologist will tell you, the best indicator of future behaviour is past behaviour. Humankind's track record on responsibility with speed is too poor to take a risk with our favourite hobby.

John St.Amant

iTrader: (1)

yup.. exactly .. and i dont have to babysit them..
just charge and go.. no cycling... no bs.. i love my lipos.

party_wagon

iTrader: (29)

I think a123 packs would be perfect for 4 cell cars. You could easily fit a 2s pack into a car and get your 15 minutes of run time out of it. Then drop it on the charger for 15 minutes & your back at it again.

John St.Amant

iTrader: (1)

Did you see the Killacycle ? It uses the a123 cells.. Im totally impressed.
I wonder if i would need a new charger too ?