A few months ago when I first heard the electric guys at my field talk about A123's a Dewalt 36V pack (which is where they get the batteries from) was running under $100 on eBay. Now I am ready to buy some and they have gone up to around $130. They are telling me that a 3s or 6s pack can be charged directly from a 24v power source without the need for a dedicated charger. This sounds very attractive to me...

Anyone has a good source for A123's?

Guys you DO NEED A VOLTAGE REGULATOR on these.. Just because the cell is rated at 3.3 does NOT mean that is the voltage at full charge. My testing shows a A123 cell "topped" off returns a voltage of 3.7 volts!!! That's 7.4 volts hitting your 6v rated receiver and servos.. NOT GOOD!

Also, while these cells are great for specific application they are NOT the answer-all batteries.. EVERYTHING in electronics is a trade off and you are trading convenience for weight. A123's have a very high weight-to-amp ratio.

I'm certainly not "trashing" these batteries they by all means have their "nitch" but you need to RESEARCH before you hop on the "trend" train.

Vicar,

These guys were in Toledo...

http://www.modelelectronicscorp.com

Mike,

I have not seen anyone who has had any issues without running a regulator with a 2 cell A123. Sure it will charge to 3.7 per cell but within seconds of use, it drops to it's nominal voltage of appx. 3.3v per cell for a total of appx. 6.6v. A fully charged 5 cell nimh or nicad is higher than that at appx 7v and stays there for much longer that a few seconds. No one that I know of uses a regulator with a 5 cell nimh/nicad. YMMV. First day off this week, going to go fly.

well, all I can say is my experience says otherwise...  And remember SAFETY comes first not cost saving ESPECIALLY with giant scale aircraft..

But hey.. It's your airplane! You have been warned. 

Enjoy your day flying while the rest of us work..

Hmmm.  Everyone I know using 6V and above IS using a regulator.  NiMH, LiPo, LiIon, 123A - all using regulators.

No sense in taking a chance on frying a Rx and maybe loosing and expensive airplane - not to mention the possible health hazard

I place a diode between the switch and the receiver when I'm running dual batteries. It does two things. It drops the voltage by about .5 volts and it does not allow one battery to drain down the other if one battery were to fail. Current will only travel in one direction through the diode. I run all 5 cell 1650 NIMH packs in my aircraft. Two batteries, two switches, into different ports of the receiver. If I'm using all the channels then I Y the second batttery into any other channel.

You can get the diodes at Radio Shack for about $3.00 for a pair of them.

I've had receivers and servos do crazy things with a full charge on a 5 cell pack. I've seen fully charged 5 cell packs charged to as high as 7.3 volts.

The problem with electronics is a spike in the current even momentarily can damage components, causing them to fail sometime down the road. If you loose your reciever while its flying-the best you can hope for is that its pointed away from anything living or expensive at the time.

Cutting cost on batteries for an electric driven moter is one thing-if the batteries ar any associated components fail you simply land. But anything associated with the reciever-it just doesn't seem worth the risk to me.