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Don't understand

Old 12-18-2007, 04:24 PM
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goirish
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Default Don't understand

I see a lot of talk about RX batteries and how many flights you can get with them. If you have to buy a new battery why not get something like a sanyo 2500. For about 20 bucks. I normally use 6v and I am running sanyo 2700. Not that I want to fly all day, but at least I can fly 3-4-5 times then recharge. maybe my thinking is all wrong. I guess if you are going to run the battery close to marginal doesn't make any difference if it iis 600 or 2600. Just my 2c.
Old 12-18-2007, 04:33 PM
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Jim Schwagle
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Default RE: Don't understand

Size and weight can be a problem. There's a heckuva difference between a 4c 700 NiMh pack (AAA cells) and a 5c 2700 NiCd pack (C cells). With a big plane I agree, but I had fits in one of my planes (Modeltech Magic Extra) trying to squeeze a 600 4c NiCd in. Other planes just can't tolerate the several ounce difference in weight, or at least the placement of a heavy battery such as that. All things being equal, I agree, bigger is better, 5c's better than 4c.
Old 12-18-2007, 05:03 PM
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Default RE: Don't understand

Depending on what kind of current you're drawing for the reciever, a 600 mah battery pack will last MUCH longer than 3 or 4 flights. Even if you're drawing 600 mA to power all your servers and reciever, which is a pretty healthy rate, the battery should last about an hour.

Brad
Old 12-18-2007, 05:11 PM
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goirish
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Default RE: Don't understand

I guess I was just using a figure of speach when I said 3-4-5 flights. I really don't know how many flights I could fly because I see very little drop in 4 flights. Even on my 4.8v I use the sanyo I think it is about 1700, not sure .
Old 12-18-2007, 05:33 PM
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Default RE: Don't understand

The other thing to remember is that a big battery will take longer to charge than a smaller one. Fine if you need the extra grunt, but if you don't why haul it?

I run most of my smaller stuff on 800mAh batteries which will charge up overnight on a wall wart. Bigger stuff gets bigger batteries and I have to think harder about charging, which makes my brain hurt[:@]

Just my $0.02 worth!

Terry
Old 12-18-2007, 07:13 PM
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Default RE: Don't understand

I have JR Sport systems in most of my planes, and they come standard with a 700mAh NiCd pack. These are usually good for 4-5 flights, unless it is on the cold side. On my regular flyer, my Four Star 40, I bought a JR Sport 1500mAh NiMh pack for $19.99 and that pack will fly all day. It is the exact same size and weight as the standard pack.
Old 12-18-2007, 07:20 PM
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Default RE: Don't understand

I have an old champion eindecker that has a cox dragonfly .049r/c on it and 3 tower tss-10 servos and a 4 ch mini reciever battery is only 100 mah total weight is 16 oz and the flights are only about 5 minutes long on 3/4 oz of fuel.any larger battery would add to much weight and it is usually the 3rd or 4th plane that I bring for a flying sesion.
Old 12-19-2007, 01:12 PM
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Missileman
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Default RE: Don't understand

I use 1500mah Nicad or 2000mah Nimh on all my planes. I can fly all weekend without worry.
And if you are using a good charger it doesn't take any longer to charge, overnight slow charge always does the job.
Old 12-19-2007, 03:39 PM
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Default RE: Don't understand

My arguments for staying with lower capacity (500-700 mAh) NiCd batteries are:
1) They give me more than enough capacity for the amount of flying I want to do in any given day.
2) They are inexpensive and highly reliable
3) They last a really long time. I have some packs that are 7 years old and still cycle and self-discharge like new.
4) It is a simple matter to charge them overnight with a C/10 wall wart for the next day's flying.
Old 12-19-2007, 04:02 PM
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Default RE: Don't understand

wow only 4-5 flights on the 700? I average 12-13 a day and have to charge nightly. Im flying a big spad and load alot on the servos too. hmm
i guess im lucky flying
Old 12-19-2007, 05:35 PM
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Default RE: Don't understand


ORIGINAL: amdhotprocessor

wow only 4-5 flights on the 700? I average 12-13 a day and have to charge nightly. Im flying a big spad and load alot on the servos too. hmm
i guess im lucky flying
I use one of those loaded voltmeters with the LED scale, and I stop flying when it gets down to 70%. That may be too conservative, but it's what I was told and I didn't want to take chances.
Old 12-19-2007, 11:05 PM
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Default RE: Don't understand

also look at the servo you are running. when i fly my alpa the 900 or 1100 (which evercame with it) i could fly all day with st 47 standerd servos. that pack would last 1 flight with my funtana digital servo's. digs's need more power. i all use a volt watch but it most just for back up every 2 or 3 flight i rechage a 2500 6 volt just peace of mind ( i would hate to lose my plane becuse of some as dumd as not chargeing the pack)
Old 12-20-2007, 10:47 PM
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agexpert
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Default RE: Don't understand

Funny,

Even the smallest servo and RX combo will never last 12-13 flights reliably with a 600-700 MAH pack. That is, unless the flights are very short and unventful.

Long ago, I switched to LiPoly. Larger capacity, less weight and more reliability. I really like the stability and shelf-life too. NiCD and NiMH are fine, just heavy, bulky and a bit too 'old-school' for me.

HOWEVER, they are cheap, fairly reliable, and the weight savings of lithium is really only important for aerobatics and pattern.
Old 12-20-2007, 11:45 PM
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JPMacG
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Default RE: Don't understand

I get about 75 minutes of flying time from a 600 mAh NiCd pack with about 40% capacity left in the pack at the end of the day. This is on a 5 servo 40-sized sport plane using standard servos (not digital). For me this is 5 flights. I tend to have long flights. Some at my field keep their flights much shorter, so I guess I could see someone claiming 10 flights with a conservative reserve.

The reasons I like NiCd are because it is very mature and very reliable technology. I believe NiCd is more reliable than NiMH and LiPO. I want to fly, not mess around with batteries, but I can certainly understand how someone would feel differently.
Old 12-21-2007, 08:05 AM
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Default RE: Don't understand

well im flying a spad with 3 futaba 3004 and a micr on the throttle, but even the guys who fly the nicer planes get 5-6-7 out of them and these are planes with 5-7 servos. I guess it makes me a little upset because i switched to nitro to not have to wait on dumbass batteries. I hate waiting on batteries. I need about 30 rx pacs and a BIG charger... I got an idea!
Old 12-21-2007, 11:44 AM
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Default RE: Don't understand

Hi!
Where do you find R6 size NiCad batteries today???? Not in Europe anymore, that's for sure!
Over here we use only NiMH cells or Lipos . You can get 2800 mAh cells the same sixe and weight as 500 or 600mAh NiCads. So why use "small" 600mAh cells ???
I solder my own batteries using GP or Sanyo cells.

Old 12-22-2007, 03:05 PM
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JPMacG
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Default RE: Don't understand

NiCd batteries are still available in the U.S., at least for now. I understand they will eventually be discontinued in the U.S. because of environmental concerns. I'm not sure when that is to take effect.

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