How to convert tx from AA to LiPo?

[0lllllll0]

Are there any write ups on how to convert my tx from the 8 AA batteries to A single small LiPo battery?

Any and all direction on this is greatly appreciated.

Thanks

[Charlie-III]

A lot depends on how many AA's your TX needs.
While I usually run regular (alkaline) batteries, I have used "rechargables" but I am concerned that they are ~1.2VPC vs. 1.5VPC (BTW, VPC = Volts Per Cell), thus I start off a bit low for TX voltage, so even when fully charged you are on the low end for total voltage.

[2500hdon37s]

Originally Posted by Charlie-III

A lot depends on how many AA's your TX needs.
While I usually run regular (alkaline) batteries, I have used "rechargables" but I am concerned that they are ~1.2VPC vs. 1.5VPC (BTW, VPC = Volts Per Cell), thus I start off a bit low for TX voltage, so even when fully charged you are on the low end for total voltage.

i use rechargeables in my radios and the diffrence is almost non existant

[Charlie-III]

Originally Posted by 2500hdon37s

i use rechargeables in my radios and the diffrence is almost non existant

Ummm....0.03VPC x 8 cells is signifigant.....at least when you are NOT on top of it.

[2500hdon37s]

Originally Posted by Charlie-III

Ummm....0.03VPC x 8 cells is signifigant.....at least when you are NOT on top of it.

it would only make a diffrence if you where racing or had a nitro, with crawling your almost never more than 15ft away from your rig so it makes no diffrence

[ernie28ernie]

I have a DX3R with 4 Eneloops, no Problems at all

It depends on the transmitter.

If you want to change your AA to LiPo, have a look in ebay or ask your local dealer. There are a lot of special transmitter lipos on the market.

Yours,
Martin

[AreCee]

Yes AA Alkalines start out at 1.5V but the voltage drops off quickly as they are consumed.

NiMH starting at a lower voltage will actually maintain that voltage before it drops off.

I have been using a 3 cell lipo 2600mah in my 3PKS for about four to five years and never had any problems and the voltage is more stable too.

Recently I switched to a Spektrum DX3R and the 4 Alkaline AAs would last about 8 to 10 hours. I use NiMH AAs 2200mah and they seem to last about the same but the voltage is more stable, until it falls off and then it's replace or recharge ASAP. I keep 4 fresh Alkaline AAs in my radio bag just in case.

[The Violator]

This is where I did my 4pk. Not exactly what your looking for, but it gets you in the ballpark.

http://www.rccrawler.com/forum/showt...po#post2807358

[losikid]

What tx do you have?

a 3s lipo should work fine as a 8AA replacement, just get some sort of low voltage alarm or cut-off

[CPT.HOOK]

may want to check some of the losi lipos some of those have a cutt-off built in but if you add the voltage of those 8 aa youll get 11.1v

[jeepcj776]

I thought about a small 3 cell lipo for my 4pl,

Use a Bec to Regulate it down and have a ton of runtime

[AreCee]

Originally Posted by jeepcj776

I thought about a small 3 cell lipo for my 4pl,

Use a Bec to Regulate it down and have a ton of runtime

Doesn't the 4PL use 4 AA batteries? A 3 cell is overkill for voltage (11.1 vs 6)

I would use a 2cell lipo and a voltage regulator to bring it down to 6V. You will still get all the run time from a 2S of equal capacity.

[gm0688]

Originally Posted by AreCee

Doesn't the 4PL use 4 AA batteries? A 3 cell is overkill for voltage (11.1 vs 6)

I would use a 2cell lipo and a voltage regulator to bring it down to 6V. You will still get all the run time from a 2S of equal capacity.

in the 4pl instruction manual it says: WARNING: Do not use LiPo It creates to much voltage. If not 4 "aa" use a 2 cell life or 5 cell rechageable. Use a LiPo if ya want though

[jeepcj776]

Hence the reason for useing a Bec, set the bec at 6 volts and never have to worry about the voltage, you could use a 6 cell lipo if you want will not make a difference

[xirtic]

For the 4pl, hobbico makes a 2 cell LiFe pack that fits perfectly in the bottom of the 4pl, and is the correct voltage when you change the battery setting in the 4pl. I have it....and it fits like a dream. No BEC is needed. I got it for $34 shipped.

http://www.gonitrohobbies.com/Hobbic...p/hcam6520.htm

[0lllllll0]

I have a FlySky GTB3 and it does have a setting on it to see what voltage is left in the battery. So I suppose I can just keep an eye on that and change batteries before it dies.

What is the voltage that you want to keep a LiPo above?

[losikid]

How about a 1 cell lipo. With some circuitry that will bump it up to 5v's and have built in charge/discharge protection. Sound interesting?

[Mr Glassman]

Originally Posted by 0lllllll0

I have a FlySky GTB3 and it does have a setting on it to see what voltage is left in the battery. So I suppose I can just keep an eye on that and change batteries before it dies.

What is the voltage that you want to keep a LiPo above?

3.0 volts per cell. I myself don't like to see them go under 3.5v Most lipo cut-off start at 3.3v

[gm0688]

Originally Posted by Mr Glassman

3.0 volts per cell. I myself don't like to see them go under 3.5v Most lipo cut-off start at 3.3v

Since the LiFe is designed for it as a battery upgrade. Its just plug and play. Don't really see any advantage to using a LiPo then regulating the voltage but have fun.

[0lllllll0]

Originally Posted by Mr Glassman

3.0 volts per cell. I myself don't like to see them go under 3.5v Most lipo cut-off start at 3.3v

Thanks for the info pal!