shag555

This really wasn't a crash, but hopefully it'll prevent someone from crashing their hard earned model. I've just completed a H-9 Extra 260 and decided to take it out and put some more "break-in" minutes on the Saito 220. I taxied around for about 10 minutes and wound it up a couple of passes just to about take off speed.

As I turned the plane around to make another pass the controls (radio) completely failed. Had this occurred during one of these "take off speed" passes, this model would have sustained some major crash damage, no doubt. The battery was fully charged (so I thought).

Upon taking it home, I looked a little closer and found that my slow charger only charges at 4.8 volts. The battery is a 6.0 volt pack. I thought that maybe there were several dead cells in this pack, because after sitting on this charger for several hours, the battery when put under load will draw down to failure in less than a minute.

Can anyone verify that there are dead cells here? It's a brand new JR battery. I either damaged it, or it was screwed up from purchase.


MPB

Flyjets

My Feedback: (51)

Shag

Glad you didn't damage your Edge and Saito 220. But you can't charge a 6 volt Battery with a 4.8 charger.

I am a bit surprised that someone flying a large model with the largest 4 stroke didn't know this.
The 6 volt battery pack needs to be charged around 7.5 to 8 volts. I would then load test it to make sure it puts out rated MAH.

The best way to do all this is get one of the Battery chargers/cycle on the market. I have used the Triton and can vouch for it.

Best of Luck

150flyer

Shag,

A Volt Watcher that plugs into one of your empty channels and is visible on the outside of the plane is also good insurance. If the battery is brand new, it should also be cycled before use to get it up to full capacity. If the battery is Ni Cad, you must do this regularly. If the battery is NiMH, then cycle it every few months just to make sure it is taking a full charge. You can get a good charger that will do everything like an Accucycle Elite for $150. Thats not much compared to what you have invested in your plane.

150flyer

shag555

This is my first big plane. I haven't had a 6.0 volt battery before either. Putting it on the 4.8 volt charger was completely an oversight. I only realized what I did after what happened at the field. That's kind of why I posted this, so other guys might have the same luck in maintaining their airplane as a whole and not many pieces.

A parallel example of what I'm talking about is that one of the guys spent 2.5 years building a scale P-47, only to crash it on the 2nd flight. Turns out he used a PPM radio instead of a PCM with a G-45. Completely totalled.

For another question for those watching, The drained battery seems to have "screwed-up" the programming on one of the hitec digital servos. I put in 5645's. They're all V. 1.04's except for this one, which is an older version. I ordered them all at the same time, but appearantly the supplier had an older version left over. Just wondering if there is a "reset" for these servos, or it is damaged.

Thanks, and I do plan on getting the more experienced guys at my club to look this thing over before, and during 1'st fly.

MPB

shag555

Just some more thoughts. I had a battery checker plugged in to the radio. It's a hobico that switches from 4.8 - 6.0 volts. I had it set at the 6.0 volt switch setting and it showed that the battery was O.K. When I moved the sticks, the battery indicator would blip around much like a stereo equalizer does. I didn't know if this was normal or not, obviously it isn't.

Believe me. I won't be putting this plane up until I have this battery problem worked out. That's why I took it to the field and taxied around in the first place, to find any problems. I just didn't expect this one. With safety in mind and the money invested in this plane, it wouldn't be worth it to just "fly it" the way it is.

Further more, I'm a little disgusted with the fact that the battery didn't come with instructions showing the polarity, charge rates, etc.

I've been flying for three years and believe (as others within my club) that I'm perfectly capable of flying, and handling this plane.

exeter_acres

My Feedback: (2)

are you talking the Wall wart??

if so, you CAN use it... it just can take a few days to charge it up (remember Ohms law??)

also regular cycling is not neccesary... cycle a few times at purchase to verify capacity, then after extended storage...and that is it....
the chemistry is better nowadays

check Reds battery clinic for info on wall wart charging
(but you would be much better served with a better charger as mentioned)

shag555

Initially, I had it charging on a 4.8 V NiCd charger. I left it on overnight. I don't know what the charge rate is off hand, as I'm not at home at present. I have charged / discharged the new pack three times and it seems to be holding a charge just fine. So it doesn't look like I damaged it as initially thought by over charging. Quite the opposite, it never received enough charge to begin with.

I've never had a battery go dead in the receiver area before. This was quite the eye opening experience, and makes me realize just how important a properly charged battery is.

I hear tell that this battery should be no problem for running four hitec 5645's and one 5945. I also thought about going with a Duralite 2700 mah Lipoly pack instead. The post on this plane in the 3D area shows guys flying all day on this Duralite pack. Is this consistent with any of you guys experience?

Thanks a million,

MPB

shag555

The 4.8 V charger was the WW. Of course, the fast charge was the Triton. I guess the quickest way to handle this, since I'm flying two planes, is buy a specific 6.0 v Wall charger.

MPB

erbroens

Just as a note , I flew a lot this plane, with a Futaba PPM and a Zenoah G-62 and the plane is still in the hangar. It´s interesting to see how PPM is blamed so often by any unexplained (and uninvestigated) crash....

(oh, and yes, there is a lot of aluminium in this plane, for my personal amusement and horror of the profets of doom at that time)

Best regards, Enrique

camss69

My Feedback: (46)

You can use the 4.8 ww charger it's just going to take longer, like at least twice as long. I've been using one for years on my 6v packs, just make sure you've left it on long enough. I would probably use a different charger if you want to charge overnight.

shag555

Here's a really scarry update... I took out the servo that wasn't functioning properly. It had a "rattle" in it like something was broken. I went ahead and took the bottom cover plate off and discovered that one of the chips that was supposed to be soldered to the board appearantly didn't get a good soldier. The chip fell off the board, and then the programming chip on the board literally burned up. Again, these are brand new, out of the box servos.

I wonder now, if that's what really drained this battery. Just imagine if this occurred during flight!!!

I'll be placing a call to Hitec tomorrow. How's the turn-around time on replacements???

MPB

shag555

As far as chargers go, I was considering the use of a wall charger for overnight charging. I do have a Triton and charged and cycled this battery again today. I then topped it off. It seems to have pleanty of capacity. I also tested the battery by running the radio / servos for 15 minutes. I realize that there is no "air resistance" being felt (IE Load being applied), but seems like the battery its self is fine.

shag555

I think this is the sequence of what happened to my battery... That little chip fell off the board that controls the servo, the servo locked in "up aileron", and the main chip on the board overheated and burned up, using all juice draining the battery completely.