i want to use a 20C 3cell with regulator as receiver pack... normal rx lipo packs discharge 6-10C... now if I only draw say that 6C from the 20C battery... will it only discharge at 6C although its a 20C? or will a 20C lipo always want to discharge at 20C min?

20C is the rated max safe current draw from the LiPo without damage to the LiPo, most have a burst rating usually anywhere from 5seconds to 30 seconds. If you only draw at 6C thats all that will come out of the pack it will not give 20C unless you draw that current.

Cheers

ok thanks... what is the max current usually from 5servos on an airplane? if I use say 130oz analog metal geared ones...

I just started using A123 batteries for my Rx's so I've been measuring how much mah's I'm taking out of my battery for a set of flights. The plane is a 1/4 scale aerobatic/3d bird. I've got 2 hs5645's and 5 hs 695's. Flying fairly agressivly for four 9 minute flights I'm only putting in 600 mah or so.

By the way, I really think A123's are the way to go for Rx batteries. No reg. required and very fast charge times makes them nice.

I know this... would like Lifepacks... but too expensive here... I can get 3cell 2200mah lipo for $17... where as Life costs $54... somewhere someone is doing us in here in SA... I can buy 2 of those 3cells and 2regulators and end up paying $60 for all... makes more sense to me at moment...

Well, I guess the first question I would ask is why? Why do you want to switch to LiPo for your receiver? What is the plane you are looking to do this with?

As I've said in several posts in the past, adding a point of failure or two to a system is just asking for trouble. If it works, don't fix it is my suggestion.

There may be underlying issues here that you have not described, but for a basic (this is a Beginners forum after all) setup, for glow operation (again, not many beginners will be starting out with "gasoline" power) setup, NiMh or NiCd is more than appropriate. And, with glow, the weight issue is not that much of an issue because you have plenty of power, so you can get large capacity NiMh or NiCd packs. So, again, why?

CGr.

I do not think that most RXs or servos will tolerate the voltage of an unregulated 3S LiPo. That's going to put out over 14 volts when fully charged, and most radio gear isn't rated for much higher than 6.0V.


Edit: Oops, misread your post. You did say you wanted to use a regulator []


My biggest issue with using LiPos for RX batteries lies in the fact that I wouldn't want to have to remove them from the plane every time I charged them. And I wouldn't ever charge a LiPo inside a plane.

You can get pretty good deals on 6.0V NiMh packs with high enough mAh ratings to fly all day long. I too would like to start switching to LiFe packs for my Rxs, but I have been getting plenty of flying time out of 1500mAh NiMh packs and I just can't justify the $$ right now.

Good luck

There is that too. Charging LiPo's require some special care. Much better off using NiMh or NiCd for generalized sport flying. If it involves flying gas large scale, then a better forum for this thread is in THAT forum.

CGr

thanks guys for comments...