it actually depends on your preference... but mostly if you run BL system, it coincides with li-po batts to compensate the vast power output your BL will release plus longer run times...

li-po

Hey guys,

I noticed this thread and thought I would offer my opinion.

There is no better way than LiPo at the moment, we may see LiFe batteries in the future, a combination of A123 as well. But for now, LiPo has no competition.

The danger in LiPo is the result of its chemical components. Lithium can be very unstable element, WHEN it is exposed to certain conditions, in which case it combusts.....violently. The conditions under which it will do this is submergence in water, reaction with certain elements (even air in extreme cases). Abusive charging and neglect. It is difficult to get any of these conditions to occur without really trying to ....but it DOES happen.

The positive side of it is this.
Longer running time
Lighter
No power fade through the discharge cycle (voltage remains constant, it wont dump)
Consistent charging
Does not self-discharge over time (leave NimH on a shelf and it loses 2% charge a day in some cases)
Faster charging

If you buy a reputable brand the discharge rate will be as it says on the box. Buying the el cheapo batteries will cost you in the long run. They normally degenerate over time and the cheap brands have been known to 'die' after 50 cycles. So if you are going this route, buy QUALITY. Buy ones that have a hard case, physical damage is a known cause of Lipo fire so the exposed cells are NOT good. Flyers use the soft packs, because in the event of a crash they immediately discard the batteries, car owners will want to use them again :-)

Factors to consider when caring for them:

Discard if heavily damaged.
Do not use in systems that draw more power than they can handle
Do not over charge.
Do not throw in water or mix with other chemicals.

For charging you need to charge them a t 1C and NO MORE
1C is the max amps input that it can take in an hour.

(Explanation: If you have a 7.4V 3200Mah battery, you take the 3200Mah, divide by 1000 and that gives you Amp hours; in this case 3.2 amps per hour.) So for this battery you need to charge it at 3.2 amps for one hour and you are done)
Another case.....11.1V 4000 Mah battery, you would charge at 4.0amps for one hour. Notice that the voltage has nothing to do with the amp rating. BUT THIS DOES NOT MEAN YOU CAN CHARGE AT 240V :-)

Now, for discharge rate, you would need to know how much current your motor is drawing to be accurate, you can find out more about that from the motor manufacturer, but gearing is important to consider as well. But for batteries, the following rule applies.

If you have a 3200Mah battery with a discharge rate of 20C, that means you can discharge it at 20 times the amount you charged it. You take the 3200Mah again, divide it by 1000 to get amp hours as you did for the charge ratio above, and multiply it by the 20C...and you get. 3.2 x 20 = 64Amps. Easy....I can tell you that a 9Turn Brushless motor at full wind up MIGHT get you 65 amps in certain circumstances, but I am sure the drifter cars even on a Novak Slyder will probably not get to that. But that is a guideline.

With regards to balancing the cells, as there are only 2 cells in a 7.4V lipo, each cell is capable of delivering 3.2V. The chemical composition of the battery cannot maintain the chemical reaction below this voltage and the battery will fail. A lipo cutoff will normally read the total voltage of the pack, and when it gets to the minimum, it will stop. If the cells are out of balance when this happens, one cell might be below the 3.2V and will fail. The battery is then a paper weight....USELESS:-)

You HAVE to have a LiPo charger, you cannot use any other charger.... LiPo is expensive to get going, but when you do you wont look back.

Hope this helps

thank for the info man its very helpful :cheers: :cheers:

Excellent words of advice sir andy. +D

So there you have it sir dencio. Li-Po it is.
There are just a few points you have to keep in mind when maintaining the Li-Po.
=)

now i know why i need those lipos..thanks man!. not for my fats this time..wahihihihih

very well said..

all the questions answered..

thanks for sharing..

thanks andy.. ready to go lipos here.. just need a balancer.. and lipo batts ofcours
need to get some deans plugs aswell.

is your police car on deans plug lance? im not.. so do i need to bring my batts on sat?

there will be cops on sat.. weehw have to fix my lights then....

how about those plates you have... any body got extras???

ok man will do thanks

What's happening on sat? What police? =/

My charger also supports li-po balancing. I can balance your li-po if you want. +D