Hey guys,
Does anybody here have experience with using Lipo's for receiver batteries? One of my biggest debates so far is lipo versus nimh for my Extreme Flight Yak I am building. I found an inexpensive ($28 from cheapbatterypacks.com) 12c 7.4 3600 pack and am thinking about that and a regulatr for Rx power. I already have the lipo charger so that isn't an issue. Any thoughts if this is a good pack and are there any issues with lipo rx packs I should be aware of?

Todd

They won't last as long, and if you use an ESC for a regulator, you're only sending 4.8 volts to the servos. You'd be better off using a 6v NiMH pack. At least that was my experience.

Lipos will last just as long, depending on capacity, but it's truly a waste of a good lipo. Lipos are valued for weight savings and for HIGH DISCHARGE capacity. There is no benefit to running lipos on your RX besides weight.

Since Lipos should be charged outside the plane, it's a real pain. Get some Fromeco Li-ion packs 2400 MAH for ignition and 5200 for rx, while you are at it you will need regulators and they make some darned-good switches too.

You WILL need a regulator with either Lipos or Li-ion. A 2 cell lipo or li-ion has a Nominal of 7.4 V and fully charged, they are delivering 8.4.

If cost is a primary concern, go with 6 V NiMH.

Your Lipo charger should be able to charge li-ions unless it's a really cheap one.

My Lipo charger ia an elctrifly polycharge 4... will charge 4 lipos of any cell count or capacity at the same time, but wont charge li-ion.... so that's where the "catch" is.... if I go nimh I need to get a charger and cost a little bit of an issue, but on the other hand I don't want to skimp on this plane and make a bad choice that will come back to haunt me.....

If you plan on getting into bigger planes, you may want to make the jump to Li-ions now. I only fly Fromeco, but there are reasonable substitutes. When I flew glow, I used Fromeco li-ions because I knew I would end-up flying gas.

You might want to start a thread about charging ions with the polycharge 4. I know it says it won't, but maybe it can be um......coaxed. I don't know why a dedicated, good quality lipo charger would be unable to charge ions. Seems like is should work, but I would'nt risk my house on it.

Use LiIon...not LiPoly.
Get a TBM http://troybuiltmodels.com/LiIonBatteries.htm 2600mah and Regulator, with the Fromeco Switch. -
5 oz all up weight for the RX and good capacity, 6 volt delivery.

The polycharge will not charge any cell count or capacity. It is limited to 3 cells per pack and a total of like 4-5 amps of charge current combined. Not that it matters for your situation, but just so you know.
I have been running dual TP 1320's in my 35% electric with no problem, but then again there is also no vibration. Still, I am giving them a shot on my 35% gas plane, too. The advantage of lipos over li-ion is their current delivery ability. In theory, you could fly a 35% plane on a single 900mah lipo (of course for only about one flight!) since they are rated for about 15-20C continuous without any severe voltage drop, whereas the very best li-ions are only good for about 2-3C. That's why you need to run such huge capacity packs. Personally, I only fly 3-4 times per plane per day, so I am going with dual 1500 lipos on the Rx and one on the ignition. Four flights will still only burn about half their total capacity, and my power system will be about 6 ounces lighter than a typical Fromeco 35% li-ion setup.

Nick,

You running that in a 35%? Come down here and show us man!!

phat

Forget Lipos, go with A123 packs.

They have all the benefits of Lipos (high discharge, relatively light weight, good energy density, etc) but won't require a regulator and are as safe as NiMH cells. Plus they have a *much* longer lifetime, capable of thousands of charge/discharge cycles.

They're not too pricey now either.

I'm going to get some for my 50cc.

sorry, but what's a A123 pack?

AJET...dude...What the heck are they...?

Check out http://www.a123systems.com/ for more info but basically they're a battery system that uses nano-technology to get greater performance without the fire/explosion risks of convetnional LiPo technology.

A number of RC vendors are now starting to carry A123 cells. Do a Google but I know that http://www.aircraft-world.com/ now have them.