I need help bad : )

[flyer1]

Hello Everyone!! I am new here, this is my first post, this forum is awesome, a ton of information here and I am learning more and more. I have a huge problem that I need some help with. This explanation is going to be long so that I can give the best details in the hopes that someone knows whats going on, so bear with me.



Of course I have the supercub, I've been flying it for the last few months and have had a blast. I've had good days with it and some bad crashes. I have had to replace propellers, nose cowls, wing struts, etc. But all in all it flies great and I love it, but lately there has been an issue thats driving me nuts, and quite frankly starting to make me lose interest in this airplane and flying altogether.

I'll start with the plane, everything is stock, no upgrades except for the batteries......and there in lies the problems. I have 6 Ni-MH batteries for it and I've read all i could on charging and so on, but everytime i fly I get the crappiest fly times, even with the best throttle management. Some of the batteries even after a so called full charge won't even go past half throttle. Below is a pic of what i have and I'll explain further.




1 stock 8.4V 1000mah
2 10.8V 1000mah batteries (these rock for hanging on the prop)
1 NiMH Battery Pack: 9.6V 1200mAh (8x2/3A), High Drain Power (batteryspace.com)
2 Two 8.4V 1200mAh Hi-Power NiMH Batteries (Batteryspace.com)


The stock 8.4V is older and I can understand that it's losing it's charge but I just used it last weekend and it ran fine, but for the last couple of days even after a full charge it won't even spin the motor to half throttle.
The 2 10.8V are a little older, my brother gave them to me, but again last weekend they killed, I was pulling outside loops, hammerhead stalls and hanging on the prop, but for the last few days, they barely give me a minute or two, and one of them last for like 30 seconds.
The 8cell 9.6v 1200m, and the two 8.4V 1200mah I just bought a few weeks ago from batteryspace.com. I cycled them a couple of times and they seemed to work great, longer flights at full power, but again the last week or so, they cut out quick, the two 8.4v don't even go past half throttle, so basically they are worthless, But I JUST BOUGHT THEM!


I have 3 chargers, the two stock chargers that came with the plane and A parkzone DC peak charger 1.8A that charges 5cell -10cell Ni-mh batteries from .5 t0 1.8A
Picture below




I am fairly new to this, both of my brothers have moved onto the trojan and lipo batteries and they love it, but I am becoming more advanced on the supercub, but I am so sick of the battery/receiver/tx problems. I don't know whats going on, I don't know if it's the batteries, the chargers, the transmitter or what? I cannot ever go full power in the fear that the engine will cut out, especially if my planes is far away, and it's depressing. I have spent a decent amount of money on batteries lately, and all this plane is doing is costing me money and time and I'm not getting anything out of it. So I have some questions for people who have had the same problems, or know more about electronics, and the super cub, and batteries and charging.


1. Where is the best place to get batteries?

2. How should I charge them? At what rate?

3. How hot should they be, at the end of a charge, even a peak charge? And how hot is too hot?

4. The old batteries I can sort of understand why they die quicker, but the 3 others are brand new, What am I doing wrong?

5. If its not the batteries, what else is it? (mind you, i have read this forum alot and I have taken the reciever out and made sure the cutoff pin is still in, checked all connections, went into the tamiya connectors and crimped them back closed.

6. How long after you fly should you wait to recharge batteries?


7. What is a great charger thats not too expensive?, and possible a voltage meter, I wish I could see whats going on inside the batter, but I don't have alot of money



In conclusion, I am new to this hobby/sport and I like it very much I find myself everyday yearning to fly, I have a lot of free time lately with the economy the way it is, so I have plenty of time to fly, but it is SO frustrating to take the time running out to the car over and over again charging batteries, loading up everything I need, driving 15 minutes to where I can fly just to have literally 3 minutes of flying time on 6 batteries, half of which are 1200mah. I need to find a solution to this problem immediately, as this problems is costing me alot of money, time, energy, and my stamina and patience. There is nothing more aggravating then being excited to fly then can't or the plane cuts out when i try anything and have to hastily avoid disaster. I hope I have explained everything so I can get some good advice and help.


Thx for any and all who respond or read this and offer any kind of advice, I really appreciate the time and energy all you SC'ers take on this forum.

thx

[flydiver]

Tough one to tease out. Like you said, it would be good to know what is going on inside the battery.
A voltmeter will not help much. But a converted voltmeter may be very useful.
$3 wattmeter: www.rcgroups.com/forums/showthread.php?t=949923

Or maybe a $12 wattmeter:
www.rcgroups.com/forums/showthread.php?t=949923

For the 'real item' expect to pay $50 but it's the best tool in your box after a good charger.
www.rcgroups.com/forums/showthread.php?t=311574

Frankly, I think it's the chargers. The pistol shaped charger is limited to 7-cells, the wall wart to 8, and the larger one to 10(?) but I've had at LEAST one of every type croak on me, 2 of the more expensive one. PZ does not make good chargers. With new batteries if they are cutting out, and the lipo jumper is in place (not removed) it sounds like you are hitting LVC.

Are you using a stock prop size? If you've put on a larger prop (say 12x6) that would cause it too by making the motor draw too much.

NiMh batteries may be less dangerous but they are actually in some ways more difficult to charge and deal with properly.

First, they hate heat. If they are getting beyond warm from charging or use that is damaging them. They should be cooled before you charge them.

Contrary to some common myths readily spread around packs should never be totally discharged. This risks reversing the weakest cell(s) and killing the pack.

Learn to do some math. If you have a 1000mA battery, and you charge it at 1A (1000mA) and it's been used to LVC it'll take about 1 hour to fill. It should come off the charger when just finished warm (not hot). If it finishes in 15" and is cold it didn't charger.

A GOOD NiMh charger will set you back as much as a decent lipo charger. They are every bit as complicated. That's what's wrong with the PZ charger, same as the plane electrics > cheap.

I have a Duratrax Pirahana that is good, but I got it used. I also have an Apache 2030 that seems to be fine-does NiXX and lipo (no balance).
Lots of folks are buying the Hobby city Acucel 6 for ~$40 (+shipping) and it does pretty much anything. No terrible reviews yet. Fine for now plus good for lipos later on.

Do some reading here-great site:
www.hangtimes.com/rcbattery_faq.html

[flyer1]

Thx for responding so quickly flydiver, I really appreciate it. My propeller is stock size, and maybe I fried the batteries or something i don't know, but my batteries come off the charger hot and then after i pull them off they seem to grow intensely in heat even after they are not on there anymore. It just sux because I just bought three of them, and the 10.8 V are killer, not to mention expensive. I'm going to try and charge them again, and load them into another SC this weekend and see what happens.

[mrmugen]

Can you take those packs to your brother and see if he can charge them on his charger? I too agree that it is probably your charger/s. The PZ chargers are good enough to get started...thats it. I have had many of them take the dirt nap. If possible try charging on a better charger.

Kevin

[duck9191]

humm if they are comming off the charger hot then they are over charged, kinda weird most of the PZ/HZ chargers i have seen under charge due to false delta peak. like fly said heat is their biggest enemy, so they maybe pretty much shot. you can tell when an nimh is fully charged it will start to get warm because the internal resistance begins to rise, its a good time to stop them there if your charged doesn't.

[flyer1]

hello everyone, thx for your help so far. I don't even use the "wall wart", simply because it sux and most of my batteries it won't charge since i have 1 8 cell, and two 9 cells. The other chargers I have, I mostly use the .5A-1.8A charger for all the batteries. It's weird, they seem to charge ultra fast, so i set the charge rate to 1.0A and it took the batteries longer to charge obv, but the same result. One the 9 cells, took a while to charge and i popped it in, and the battery could only get the prop a little past half throttle, and this is on a 10.8 volt battery. I don't know whats up, but my father has a super cub as well as all my brothers, today or tomorrow I am going to charge them again, and try the batteries in their plane. I guess if it doesn't work still it's the batteries, and I will have to go spend more money. Its frustrating........I've been all over this site and youtube looking at videos of people flying their SC at full power for a long time and I wish that was me, Once im in the air, I can't dare to slide up to full power or the motor will shut off. So I can only fly at half speed. All I want to do is fly, fly, fly that is why i have 6 batteries, but 3 minutes fly time for 6 batteries is so sad, so sad. Well thx for the input guys.


BTW......What batteries and chargers do you guys use and whats your feedback. So I can pick the best ones.

[SCC]

Hi Flyer1.
It may be worth checking that the LVC jumper is still in place.

[flyer1]

Ok everyone, I took all my batteries my plane and all it's accessories to my fathers house to test my batteries on his plane. The good news!, I didn't even try to charge them again, so they went into his plane cold and guess what they fired right up and ran perfectly, no engine cutouts, or stoppage. I took the same battery and put into my plane and guess what it ran too !?!! But only some batteries did. All my batteries ran fine in his plane but not in mine, so now i pretty much know that it's not the batteries. If i run my throttle up quickly the engine shuts off, but on his Tx i can run the throttle up and down as fast or slow as i want with no problems. So now i think it's either my Tx or Rx. And thank you SCC, the other day i took the reciever out and the LVC jumper was in place, i even took it out and replaced it again. So I'm glad to see it's not my batteries (it seems) , but now onto what it really is.

Any advice on how to find out whether it's the receiver or Tx. As I would really not like to purchase both of them, cause the Tx is 30$ and the Rx is almost 30$.

What kind of Tx are you guys using? Stock?

Thx to all who read and try to help me

[flyer1]

Oh sorry I forgot to mention, the higher voltage batteries seemed to work better and lower ones didn't. For example the 10.8V 9 cells worked ok, the 8C 9.6v worked a little less and the 8.4V didnt work as well or at all. It seems as though there is a voltage problem.

[flydiver]

What the lipo jumper does is set the LVC to 8.8-8.9v. When the voltage goes below that, it quits. Since your more powerful batteries work it's because they sustain the voltage above that setting.

A common problem and the reason SCC sent that pix is to make sure it was in there. Lots of people have it fall out in a crash and have exactly your problem. Plane will run at part throttle but cut out when pushed at all because the voltage drops.
You could have seen that with a wattmeter immediately. The recommendation to get one stands.

Try a different jumper from a common PC (mother board, Hard drive, etc.). Maybe something is wrong with the jumper and it's not making contact.
MAKE SURE IT'S ON THE CORRECT POST!!

If it's still not working it's the RX. Something is not right. Transmitter is sending signals, RX controls the LVC.

[flyer1]

hey flydiver, thx for your input i appreciate it. I have had some hard crashes, some hard enough to jar the receiver loose from the housing, i'll check the LVC jumper. Tomorrow I am going to take my batteries and fly with another plane (give them a full charge) and see what happens. Unfortunately, I don't have any spare jumpers lying around, maybe ill take one out of another cub and try that. If that doesn't work, maybe ill jump off a cliff ; /. Again, thx to everyone for all their help, I love this forum and am very glad it exists.

thx

[flydiver]

Still got those ACT wires? Cut one, strip the wire, twist/solder together the ends, cover with shrink wrap. Makes a good jumper.

I'm assuming you aren't using ACT----Absolute Crash Technology

[flyer1]

hahahah Absolute crash technology.......NO I don't nor have I ever used that garbage, if i am going to crash, I would rather it be of my own doing. ; ) thx again

[SCC]

Flyer1
It could be your Tamiya connector on your esc/Rx. If all your batts work on your fathers cub, then his connector may not be worn as much.
The rolled tin pins are notorious for bad connection.

I would bin the Tamiyas and change over to Deans ultras on Battery's, esc/Rx and chargers.

Good luck.

[mrmugen]

How bout that motor? It may be drawing mad amps and causing the pack voltage to drop below lvc when WOT. Might be your bear.

Kevin