brett65

My Feedback: (18)

I am getting a parkzone corsair and blade cx2 next week, and I need some knowledge about the lipo batteries. I want to get an extra battery for each, but get a less expensive brand, and a decent charger for them. Thanks!

What doe the C rating mean?

Do they have to be discharged?

Is fast charging bad for them when done repeatedly?

Is the turnigy accucycle6 a good charger? (recommendations welcome)

Are zippy flightpacks any good cause they sure are cheap?

opjose

"C" is the discharge/charge rate of the battery

1C is approximately what the battery is rated at for 1 hour of discharge... e.g. a 2800mAh battery will discharge at 1C ( or 2.8 Ams ) in 1 hour though this is usually less.

A battery of this size capable of 20C will discharge at 20 times this rate or 46Amps, but in 1/20th of an hour, so to speak.


Re: Discharged?

Eh when you use them.

I think you are referring to recycling charge cycles, which for LiPo's the answer is no.

Re: Fast

It depends upon what rate.

If you charge the battery at 1C it will charge up in an hour w/o hurting it.

What that 1C rate is, is dependant upon the battery capacity...

So a 2100mAh battery would be charged at 2.1Amps to get a 1C charge.

A computer controlled charger is the best way to go with LiPo's to assure full and proper charges.

Re: Charge

I haven't tried that one, but I favor the TH Accucyle charger

Re: Zippies

As "Tony the Tiger" says: They are GREEEEAAAT!

I have a dozen or so of them.

All produce slightly better than the stated output and hold up well.


A note on LiPo's.

LiPo's have a FINITE lifespan.

They typically can last over 100 discharge/recharge cycles but by around 100 cycles they start dropping in capacity.

It is possible to hit 300+ cycles with them if you keep the current load on them fairly light and balance them periodically.

Any time the packs get very warm to hot, you are reducing their lifespans significantly.


View LiPo's as "fuel" that you purchase up front, in that they are still a finite resource, and they are not the renewable resource some people make them out to be.

Electrics are wonderful, but spending a few extra bucks on a good balancer, charger, etc. goes a long way to maximizing what you get out of them.

Care and feed your LiPo's properly and they will be good to you.

And don't forget that you also - NEED - a good Watt meter!

Without it you will not be able to tell if something is amiss with your EP configuration.

opjose

Oops double clicked!

hugger-4641

My Feedback: (6)

Dito everything opjose said, especially the zippy batteries. I have several Zippy's and Rhino's, they are great batteries for less than 1/2 $ of stock battery. 2200mh is the biggest I've put in my Corsair, but I think some other guys here have used some larger ones. Check out the F4U threads in "park flyers" forum if you haven't already.

brett65

My Feedback: (18)

So do I have to watch the C or discharge rate so that I don't overpower my esc when buying extra batteries? I think it has a 30 amp esc in the plane. And what is the watt meter used for, is it for checking the pack before a flight? Can a nice industrial voltmeter do that?

whitecrest

The maximum amount of current flowing through your ESC will be determined by the motor and prop selected for your plane. Your battery and ESC capacity should be rated to handle this amount of current without overheating.

The wattmeter is a very useful tool that will allow you to measure the amount of power that is being delivered to the motor/prop as you advance the throttle. This information will tell you if you are overtaxing any of the components of your power system. As a general rule of thumb, none of the components of the power train (battery, ESC, motor/prop) should be become very warm (too hot to touch) while delivering an excellent power level (approaching 1:1) to the propeller.

Some digital voltmeters may serve in place of a wattmeter if they can measure high current levels of up to 30 amps. Many meters can be effectively extended by using a current shunt and measuring the voltage drop across it under load.

There are many excellent stickies describing the essentials of electric power systems. Once you are familiar with just a few key concepts, you will have no trouble selecting the right components for any power level. The brushless/lipo combination is a very effective power system.

opjose

This has nothing to do with the battery packs themselves ( except for the voltage output... ).

Rather "overpowering your ESC" is determined by the prop & motor combo you select.

This is why a Watt meter is important.

Change a prop and you "pull" a different amount of current from the battery via the ESC.

The only way to tell if you are using the wrong prop is by using a Watt meter.

No on the Voltmeter.

The Voltmeter merely tells you the voltage of the pack, which is already known.

You need to be able to determine how much current is running from the battery into the ESC, and this is determined by your entire power system.

hugger-4641

My Feedback: (6)

Very good advice above! Read and learn all you can about electric flying and lipo's. Short answer as far as an extra battery for the corsair you are getting next week. Get a zippy rhino or flightmax 2200mh 20c or 25c from hobbycity and you should be fine (about $20). I know they have the flightmax 2200hm 25c in stock right now cause I just bought a couple, if you order something not in stock, it may take a few weeks to get it.

hugger-4641

My Feedback: (6)

Just to be safe, guess I better clarify to get a 3cell 2200mh 20c or 25c. Hobbycity lists it as "2200mAh 3S1P 25c".

aeajr

My Feedback: (2)

Should be fine. Check dimmensions to be sure it will fit the battery compartment.


This and many similar questions can be answered by reading this e-book:

EVERYTHING YOU WANTED TO KNOW ABOUT ELECTRIC FLIGHT
http://www.rcuniverse.com/forum/m_7100376/tm.htm