Dave Shadel

Any info appreciated. What is the best 4s charger for LiPo 14.8 volt batts? Thank You.

will

You might check out the new Astro Flight charger. It'll get the job done. They seem to be in short supply.

aerobaticsdude

Schulze

http://www.rc-direct.com/Schulze_chargers.htm

d_wheel

There are several good choices. What is the amp hour rating of your pack?

Later;

D.W.

Dave Shadel

They are 1500 mah

d_wheel

There are several good choices. Check a few of them out at:

http://www.espritmodel.com

http://www2.towerhobbies.com/cgi-bin...?&I=LXFWW2&P=7

http://www2.towerhobbies.com/cgi-bin...?&I=LXCJG7&P=7

http://www2.towerhobbies.com/cgi-bin...?&I=LXFBL2&P=7

Later;

D.W.

Steve Neu

My Feedback: (1)

Hi Dave,

Schulze has by far the best built charger for hobby stuff. The interface is simple. The same charger can charge Nicads, Nimh and Lithium batteries. RC Direct handles them here in the states.

Steve Neu

Jason W M

My Feedback: (6)

Steve is definitely right - the Schulze chargers are by far some of the best! I use the 330D and 636 chargers. I use em on packs as big as 10S LiPos!

BEC

I'm moving towards more lithium and less other chemistries.... so I really like the Astro 109 (I have two now). For an all-purpose charger, you can't beat schulze (and I kept my 636, but sold the 330d) but for LiPoly only the Astro 109 does a great job and is simple to use.

Dave Shadel

OK, got the Schultze. The airplane is a Diablotin Mini, Hacker B50 14S, 15x10 or 16x10 APC electric prop. Lipoly 14.8V, 1500 mah. Weighs 3.75 pounds, flies like a toad! Sent the batts back to Dymond to add a cell to each of the 4 packs. We'll see how it flies when they come back. Thus far I am not impressed by what I've seen. Anyone have a comment?

Dave Shadel

There must be someone who wants to step in.

Matt Kirsch

My Feedback: (21)

Step in, or step in it?

I swear I remember making comments on this particular setup somewhere...

Additional thoughts:
What gearbox ratio are you using? You may be trying to literally pull the battery's spleen out through its nostrils using a pipe wrench if you're drawing too many Amps with the motor setup. More cells in series will only make the problem worse if this is the case.

Dave Shadel

6.7 to 1. Batteries don't even get lukewarm.

clownie

I assume you are saying 4 1500mAh cells total, not 2 sets of in parrallel? If these were 1950 cells, they MIGHT put out 30 amps with a 16/10 prop, giving 61 ounces of thrust and let this plane fly like an Electra. But 1500 lipoly cells are only rated for maybe 9 Amps so they will die soon, and only put out 30 or 40 ounces of thrust resulting in the toad you mentioned. A quick volt, amp or rpm check would confirm the cells' inability to perform at this level.
10 good NiMH cells of 2600 capacity or above would get you 70 ounces of thrust with an 18/10 prop (30Amps), or 13/14 large nicd or NiMH cells would nicely power a 16/10. As above post said, a 5th lipoly cell would just make matters worse by raising amps and turning the cels into microwave popcorn sooner. These things can be simulated at www.flydma.com, they have an electric calculator, though it doesn't show lipoly cells as small as 1500. To make this work as a lipoly solution would require like a 2100 5s3p pack, i.e. 3 five cell packs in parrallel, with a capacity of 6 Amp hours, and a reasonable max draw of 35-40 amps. WWW.espritmodel.com has thsi plane and makes reasonable powerplant reccomendations. If someone at Dymond RC said to run single 1500 lipoly cells like this, well he/she is on crack. The B5014s 6.7:1 is allmost too cool for this application. 5.2 Gearbox on a 13s would be easier to fly on 10 cells.
Brian

MAKdaddy

My Feedback: (5)

Put a YS on it!!!

Dave Shadel

I should have. It would have been a whole lot less trouble.

Myron

How much you wanna spend???


www.cadex.com

look at the 7000 series of chargers... They are WAY COOL and have more features than ANY R/C charger... They are designed for cell phone and laptop "fleet" type customers but you can buy a universal adapter to do the R/C packs of all shapes and sizes.... Yes they cost as much as 2x 9Z radios!!!

Myron

clownie

I stand by my above post. Your Hacker draws too many amps for a small Lipoly pack, and amps only go up as you add cells. You could go lipoly by running several packs in parrallel. That motor and that gear box really wants more cells as in my post. A "hotter" Hacker B50 with the 5.2 gearbox could fly like crazy on 10 cells (big NiMH or NiCd). Or you could puty a YS on it as the above genius said, but you still need some math, like right prop, fuel, how to buy paper towels to wipe the castor oil off when you end each flight, and where to fly a noisy beast... I figured this was an electric forum, but electric solutions require a bit of forethought.
This is the wrong motor with the wrong prop and the wrong battery. Other than that it should fly like crazy...
My Mini Diablotin hovers with a B5013S/5.2:1 and 10 cells and 18/10... Makes about 100 ounces of thrust on the rare occasion I need full power...Buy your next electric at Esprit model.com and let him spec the motor/prop/battery...

Dave Shadel

The problem was solved by using TP 5S3P 6000ma. Works great!

clownie

<problem was solved by using TP 5S3P 6000ma. Works great! >
That was what I suggested in my first post, glad you are flying well. Sorry if my middle post got crabby, the YS posts bugged me.... Brushless motors are very versatile, but Lipoly batteries are not.. A given brushless motor can be stretched by bigger prop/lower voltage-or higher voltage and smaller prop etc. Lipoly cells cannot be pushed, their voltage drops or they become dangerously hot or both.
TP is coming out with a new series of cells over the next few weeks that are rated 8C/10C in 1900 size or 10C/12C in 2100 size. The dual rating means 8C mean max average output and 10C max peak output (in the case of 8C/10C). Size and weight will be the same as current 1900/2100 cells. This happens by making the internal resistance lower so less heat is generated in the packs themselves.
Brian

Dave Shadel

The reason for the YS post is because I am the YS importer for the USA. It was meant to be a joke.
I now have three different types of aircraft, all of the higher performance varieties, and all work to my satisfaction. It would have been a helluva lot simpler if these combinations were easily found in the big book of electric knowledge, and significantly cheaper, too!
MY THANKS TO ALL WHO HAVE HELPED.

clownie

Sorry to beat a dead horse, but your "big book of electric knowledge" thought gave me a few ideas. www.Flydma.com is the website for Diversity Electronics. He sells planes and motors and premium battery packs (but no Lipoly yet) and in the battery section he is very clear as to what each cell will and will not do. He makes practical guidelines for how many amps to ask of each type of cell with comparison graphs of volts over time at various loads. He also posts a free version of electricalc which even includes some lipoly choices, but doesn't acknowledge the amperage limits of Lipoly cells.
I also think espritmodel.com is a decent site, he sells many different classes of planes, and makes "good" and "better" powerplant setup suggestions. If you had a certain model, find a similar one on his site and take those reccomendations as a starting point. Or buy from Esprit, New Creations, or Aero_model in AZ and take their advice for powerplant.
The most important thing to get right is amperage. Once you find out what motor/prop/cell count gives you enough thrust/pitch speed, the amperage tells you what type of cell to choose. A Super Whattmeter is a good way to spot check amps and see if your cells are putting out rated volts under load. Kan 1050 NiMH cells are good up to 20A or so, Sanyo 2600 NiMH or GP 3300 for very high amp applications or CP 1700 for high amps at lower weights. Lipoly cells are good within their limits or can be bought in parrallel packs to share amps accross packs. The new 1900 and 2100 cells from TP will revolutionize this whole industry if they live up to advance specs...
Bad electric advice is easier to find than good. I am one of the few electric guys at my club, and mainly see flying electric turds.
Brian