mac853

In the case i had asked this question before, unfortunately nobody answer me.
Could anybody help me to choose, at least give me the advise for this "strange" situation.
There are allowing LIPO and NIMH running together, but with different voltage and motor power.
But i don't know which kind is better for me, even not sure if LIPO is the good choice with these kind of race rules, then i guess we have no weight limits:

KV, Voltage, RPM

6200 (6.5), 4.8 v(4cells NIMH), 29760

4600 (7.5), 6.0 v(5cells NIMH), 27600

4000 (11.5), 7.4 v(Lipo), 29600

Just give me a little opinion to make a choice, please.

Best regards

Drifting101

iTrader: (8)

If i were u i would go with 11.5 and lipo

mac853

In the case i just own 4200 sho batteries, since there you insisting to convince me using LIPOs?

Then, which 1 of LIPOs run well in spec races?

I am miss something, not only 11.5, even 4000kv is accepted.

How about if i try LRP 10.5 stock spec, any good?

I am not sure if Orion 10.5 has just 4000 or higher, could naybody confirm this, please?

irgo

Well as i wear both of this technology, it all depend :
Do you race or no
if you do race Use Nimh for now,
if you do not just race, you'd better use Nimh,
if you are just having fun and wanna feel the best technology
youd better Used Lithium Technology

There is more of This Lithium Technology
Lithium-ion , Lithium Polymer (LIPO), Lithum Manganese.
Yet LIPO and LiManga is better in capacity
and Lithium-ion is easy to do overcharge.
you should coose between them, since you decide for an expirience.

Other than that is Lithium Capacity,
wich is depend on your technology Engine (ESC and MotorDrive)
since you had this stock brushless tech, i quote 'LRP 10.5'
For Lithium 4600mah capacity it has been quite better than
Nimh 4600mah, since you are wearing Brushless, wich is Super efficient,
and Lithium 4600mah is more lighter than Nimh 4600,
this will reduce the cost of power at your car,
you will feel better acceleration (not just top speed), because less weight.
So even with the same capacity, you will steel feel the diffrent between them. for the same Motor tech, at almost equal Voltage 7.2for nimh and 7.4vfor Lithium.
wich Lithium on you motor will generate more RPM rather than nimh.

after you understand this there was another Unique problem on Lithium it is
caled density, Lithium had great in Density,
Pick any of Lithium by 'C' rate some is 25C or more,
it is important when in the future you would like to upgrade your MotorDrive
to such 9.5 8.5 or so,
'C' Rate mean how many time to Draw your Current
example : you had 4600mah of lithium capacity x 25C = 115000mah
it is called maximum Dischage capabilities,
while some motordrive stock class capable to reach Draw 100amp
then this battery will be required.
example : you had 4000mah Lithium x 25C = 100000amp
this mean you can only draw you Battery to maximum 100amp
wich is pushing the limit of you battery, on some case you will need more than that, thats why 4600mah is minimum requirement for now.

There is also so caled 'Burst rate' also 'C'
but Burst rate is happen only once for example 10-20 second
example : Lithium 4600mah 25C Burst 30C
meaning when you punch your car start from zero speed, it will be able to push your battery to 4600mah x 30C = 138000mah (138amp) for 10 second,
meaning better initial acceleration, rather than Normal Rate 115amp.
once again depend on you MotorDrive capabilities.

Burst rate can be re used when the battery rest on maximum normal rate
or less, on some time, this is the habit's of the Lithium.

So Choose Lithium Wisely by Normal Rate and Burst Rate.
note: on aeroplane of Heli rc this Burst Rate is required to push the craft up to the sky high.

So Find Lithium not just by it's Capacity,
but watch the C Rate and C Burst Rate.
if the Product doesnt show The C Rate Do Not Buy them, you will waste money.
C list 5C , 15C, 25C, 30C, or more depend on the technology today.
Capacity for 7.4v even 10000mah already exist, perhaps today there is more.

Now if you are willing to raise you RPM used more then 7.4volt just for fun on your 10.5stock, but if you change your battery more than 7.4volt you will required suitable ESC for Lithium, some Of ESC that capable to work on 14.8volt lithium. watch this it is verry important before you would like to used Lithium Technology. any Aircraft Electric already used this kind on ESC.

Charging Capabilities, Lithium is only can be Charged with Special Charger For Lithium Only.
Important Better Used Lithium Charger With Lithium Balancer, This will make your battery Last Longger and Keep it Performance.

Lithium Only Can be Charge for 1C , meaning one times it's Capacity
if you had 4600mah of lithium, Set Your Charger on 4600mah only. not more than that,
Only Lithium ion can be charge litle bit more than that, about 1.5C. for safety.

Brand, im sure you can handle this later, because, Lithium is so Easy to build by many Companies, after you Understand all of those above, you just pick any Brand you can trust.

Big Note before you all try Lithium, there is called
Super Charged ion Battery,
this Technology is verry New, and it will required to Charged 5 minutes only.
who invent this, it is Toshiba.
it is safety even with crush, and hight temp 99degree the battery wont explode, and still keep up the performance voltage.

Watch this one

http://www.youtube.com/watch?v=3ijaeg3cg7M

http://www.youtube.com/watch?v=M7Nhe...eature=related

mac853

Irgo, wait wait, these kind of Toshiba is not available for rc cars.
I don't get so well, i don't understand with that complexity explanation, could be a little bit easier?
Of course i will have to buy those specifically only for LIPOs if i need this technology.
But my question is on:if i want put to run a high voltage battery with high turn motor, rather than low voltage with low turn.
This is just my point.
Anyway thanks for your lipo explanation, in the case learn another kinds.

HI_808

Lipo = racing with less trouble.

mac853

If i use lipo, i need to add alot of extra weight.
Example: 4cell 4200 sho are just around 290G. I have just moving my receiver and AMB to battery side just because 4cell have much more space, to make balancing of both sides.

If i purchase those latest 35C 5000 of Reedy with also 290G, as you could see, there's no enough space to install receiver and AMB due the lack of space.

So there's the matter i have, i have to buy LIPOs than add weights to becoming the car as heavy as with NIMH, for myself, there's no any advantage.

For another case, my orion 4200 sho, has never any troublesome for me.

HI_808

Oh, I see. You've got yourself quite a dilemma. While lipo is far less troublesome in terms of reliability, based on the info you just provided, the best setup to choose likely depends on the track that you are running on. I am not sure about how much straight-line speed a TC with 4 cells and a 6.5 would have, but I'm thinking that a TC with lipo and 11.5 is probably faster in a straight line. Cornering and braking would definitely be won by the lighter setup. Some kind of weight restriction may be necessary though. If someone shows up with a TC with a lipo battery mounted down the middle like the Losi or Team Magic car, it seems to me that they'd have the best of both worlds. What do the race organizers plan to do about that?

bxpitbull

iTrader: (6)

After a hiatus, fellas, the PITBULL is back! I have been watching the boards and see not much has changed other than the fact that lipo and brushless are top of the charts. To dude that asks, read around...sub-c's arent holding a can of piss next to lipos when you want to race back to back...and are proving themselves (sub-c) to be unstable when recharging...they can go from cells to mini projectiles. Go lipo, go fast and see you in the winners circle!

mac853

Not so dilemma, the problem is the matter of no 1 around me try it before.
Because this is just the theory without proved which provided by organizers.
The problem is as light as better, our track is so small, smaller then half basketball rink. The corners are so tight, so provoke always undesteer for the drivers even your car has traction or not.
So 7.4 lipo, is good on the straights but not so good as nimh on the punch.
About those 2 middle battery cars, as i know both of them are so much heavy and those cars are not good on spec races just with 3 belts, i wished has a "conventional" style car then add a little lead to balancing it.

bxpitbull

iTrader: (6)

Mac, how hard into the turns are YOU going? into the turns, rolling the throttle, lipo is just as good if not better. If you punch hard into the turns, of course you will experience a slight voltage dip. But with lipo, the thought isnt to worry about a turn or two, its the duration; knowing you have as much juice from the first minute to the fifth with minimal loss in punch when you need it. Sub c's, better get the most out of them while you can. Unless you are on the pro level, count on the opponents mistakes, go lipo, go steady and have a good time. PERIOD.

mac853

Yes you are right just because i felt so the nimh are going down time by time, but lipo need also to balancing isn't it?
Then could explai me the process of lipo balancing, please?
If run with lipo could anybody suggest to buy lower capacity then with high c like orion 3800?
And how many lipo packs, in the case our main race is going per 45 min, 2 packs ins't enough?
Or the coming soon Reedy 5000 which i could put higher A to charge.

Suggest me, please

bxpitbull

iTrader: (6)

But if you have a quality charger, balancing shouldnt be an issue. Unless you run an enduro, running a lipo pack to the brink of flatness, 2 and 3 heat per weekend, shouldnt push you to balancing for every race weekend. I have laid it down with nitros and at the end of weekend, cycled my packs and been ready for action the following weekend. the choice is yours. best bet, if you want to lay it down, safely and for concurrent races, GO LIPO! End of discussion.

mac853

But what charger you are using.
I wished a good 1 from US/EU, how about Core rc 20 or maybe Trinity i-balance, the brands of HK which i would not buy it. I have heard of fake chargers on the chinese market, many people bought those cheap chargers then explode their nimh in the home when charging it.

HI_808

pitbull,
Welcome back!

mac,
Lipo actually feels a lot faster than nimh overall. The reason is, nimh drops in voltage under load more than lipo does. When I first started using lipo, I didn't know why I felt the extra power because I thought nimh was suppossed to be a punchier battery. Then one day, I switched out my lipos for some IB4200 nimhs and the lipo cut-off circuitry on my ESC began going off right after getting on to the track. To troubleshoot the car, I lifted the car off the ground and punched the throttle. The lipo circuitry didn't kick in. Since the lipo circuitry works by detecting low voltage, that made me realize that nimh voltage drops off significantly under load. On this forum, someone used a Novak Sentry and recorded voltages from nimh and lipo under racing conditions; his findings were the same as mine.