I got a extra 300 today boy I must have been good this year. I have found some trim covering in the box that cannot seem to find where it goes does vectorflight usually send some extra covering also I got the wing halves joined and in doing so the braces really scraped the epoxy off when I put them in so as I put the them together I put the epoxy that scraped off down the middle of the wing braces so I hope it will be OK. It said to use adhesive tape on the center joint what kind of tape are you guys using for that. And one more last thing what size Rx pack are some of you using I don't have a 1000 mah pack but do have two 600 mah packs that I can use if that would be OK. Thanks guys.

There usualy is a little extra covering in the box for repairs. The tape should have been used to hold the wing halves together as teh epoxy cured, I assume that you used some other method that provided good results...

You coild fly the plane with a 600ma pack, but I'd monitor your battery very carefully. A 1000-1200ma NiCD pack is plenty of juice and very cheap too!

Yes, Vector Flight is good enough to throw some scrap covering in the box, in case you ever need any. Don't worry about the epoxy on the wing joint. It's just important that you got the two pieces joined on a flat surface, and as long as the two are tight together, you'll have no problems. A little epoxy goes a long way.
As for the battery packs, if you have enough open sockets on your receiver, you can plug in a second battery pack, and/or switch assembly into any open socket. That way you'll have two battery systems. If one switch or pack goes bad, the other will still be working, and with both turned on, you'll also have double the mah. 2 600mah = 1200 mah. However, I believe you'll have to charge them, one pack at a time.

Tanks guys what about using a Y plug for the two battery packs.

The two battery pack idea seems like it would work, but there are somes things to do first.
a) you should have a blocking diode, Schottkey preferred as it will only drop
about .2 or .3 volts versus .7 volts for a silicon diode, in series with the
positive wires going to the receiver. Because if you just plug them in to the receiver
in essentially parralel configuration, If one pack goes low, the other pack will try and charge it up.
They will sacrifice powering your receiver for being balanced electrically.
If however you have a blocking diode, the one pack won't see the other.
Put a secondary charge jack on the battery side of the diode if you use a charger that needs to sense
battery voltage, if using a wall-wart, don't bother with the added charge jack, just charge each pack
seperately

Bumstead I am no expert, but I have read several times in articles and such that the batteries will not try and charge each other.

Ramduster be sure to check out the rcbattery clinic website, it has lots of good info and addresses your question.

The RC battery clinic webpage http://www.rcbatteryclinic.com/ says

¨Many pseudo battery "experts" put forth the argument that plugging two battery packs into the same receiver with out blocking diodes is NOT a good thing, claiming that his creates a host of problems and the two packs will end up fighting each other or "cross charging".

These concerns show a lack in the understanding of the charge and discharge potentials involved in Ni-Cd cells. One pack cannot charge the another (equal number of cells) as the discharge voltage of a pack can never be as high as the voltage required to charge the other pack.¨

From what I hear here on RCU "Red" Scholefield is one of THE authorities on RC batteries.

Also, be sure to use 2 seperate switches if you go with 2 batteries. If not the rx will stay on.

And quoting the website again ¨Individual charge jacks must be provided for each pack (and not interconnected)¨ So you cant use a y to connect them.

Thanks the rcbattery clinic is a big help and I put it in my favorites. today I hunted around and found my 2 year old ultra stick battery that is 6.0 volts and 700 mah pack so if it checks out OK what do you guys think about this battery for the extra.

Hey Gringo, I am not a battery expert or even a psuedo one, just rather safe than sorry.
Your contention that the charge voltage exceeds the potential of the other pack is of course
correct but what happens if the failure of one pack is not simply a voltage imbalance
but a shorted cell, then what will the good pack "see", my contention is that it will use the
positive rail in the receiver to dump its charge through the short as well.
That's why I suggested the blocking diode. Not just because of a pack imbalance.
If the guy asking the question knew all that stuff he wouldn't have asked in the first place.

Bumstead, after posting that I was afraid you might take it the wrong way. I am sorry if you did.[&o] I was just sharing what I had read.

As far as what would happen with the bad cell I would be curious to know and I am going to post over in the battery section. Maybe some "true" battery experts could sort it out for us.

ramduster, the 700 pack is still a little small IMO for the plane. Correct me if I am wrong, but I have read here on RCU that a 6 volt pack drains faster than a normal 4.8 volt. So in essence you will get less fly time out of a 6 volt pack than a 4.8 volt pack of the same size. Of course with the 6 volt pack you do get faster servo speed and more torque.

Unless you want to quick charge frequently I would recomment a 1000mah pack at least. I have some larger packs 1100-1850 in my planes and they are great. When fully charged it seems like I can fly all day.

You will get more flight time with two switches and two 4.8 volt 600 mah packs than one 700 mah 6 volt pack.

BTW you cant connect the 6 volt pack and the 4.8 volt pack to the same rx even if you set up 2 switches.

Bumstead, looking further at the website here is what he has to say

" Since shorts rarely occur in fully charged packs the risk of one pack "dumping" into one with a shorted cell are insignificant. A simple ESE preflight test would detect a pack with a shorted cell.

While it is a fact that the typical failure mode of a battery is for a cell to fail shorted there are some subtleties here that escape many people. First,one of the major causes of "battery" failure has nothing to do with the batteries themselves but rather with a switch or connector in the battery circuit. The dual redundancy concept is to protect against the failure having the highest probability - that being the circuit path from the battery to the power buss in the receiver. Adding more components to this path, like regulators and/or diodes isn't going to help the matter but rather adds to the probability of failure.

Perhaps the following discussion on the nature of shorts will better help the modeler understand.

While it is agreed that shorts are the failure mode in Ni-Cds batteries one has to look further into the "when" of the failure.

A short develops in a Ni-Cd when conductive particulate bridge the separator or the separator itself deteriorates to the point where it allows the positive and negative plates to touch. Rarely does the short occur all at once but rather building up a very small conductance path termed "soft shorts". In a charged cell the energy in the cell will blow away any short as it tries to develop. You've heard about "zapping" cells. The cell actually zaps itself before the short can develop. Only in cases of severe overcharge at high rates can the separator melt down to the point where the plates contact each other (hard short). In this case the energy in the cell then dumps and we have what is referred to as a hot steamer, the electrolyte boils, nylon in the separator melts down and is forced by the steam through the vent. On some occasions the vent is clogged by the molten nylon separator and becomes inoperative causing the cell to rapidly disassemble. So under normal circumstances a cell maintained at some state of charge is much less likely to short than a cell that is completely discharged. It should be noted however that the self discharge increases rapidly in cells where there is a short building (high resistance -soft short) due to separator deterioration and/or cadmium migration. One other shorting mechanism is a manufacturing defect where the positive or negative collector tab bridges the opposite plate. These usually fall out before the cells are shipped or assembled into batteries.

Preflight procedure should involve checking each battery separately. First check each with ESV through charge jack. You should get nearly identical readings, then switch one on, check controls, switch off and then switch on the other battery, check controls again, then turn both systems on and fly with confidence."

So if someone didnt check BOTH packs before a flight then the diode would eliminate that risk.. although a relatively small one.

I guess thats why its good to know, if you want to elimante the risk, check the batteries or install a diode.

Guys I think I will just get a new battery pack I don't really what to put two switches in the plane. I think the 700 mah pack would work OK I could get about 5 flights out of the ultra stick with that pack and still be OK but the pack is old and I would hate to lose my new plane to a battery pack besides I always take at lest 3 planes to the field with me and some times get kidded about bringing all the fleet with me. Now I probable should put two switches and battery packs in my 1/4 scale plane just for safety sake but the battery in it is 1800 mah and is doing OK. thanks for all the help guys.

No offense taken, just glad to have some better info on an interesting subject
Thanks