jbeech
rrAdvertiser
Location: Sanford, FL (Orlando area)
| I find a 2400 mAH pack works for me but I monitor before EVERY flight. I must respectfully disagree with Mr. Van Scoyk because I have plenty of experience charging at 2C (30 minutes for a fully depleted battery pack) and SCR-type cells can be charged at 3C or even 4C also.
However, because I enjoy the fellowship with my friends nearly as much as, or even more than, I enjoy the flying itself I will charge at 2C in the knowledge the batteries can take up to 4C (a 15 minute charge from fully depleted). Also, because I can easily spend 15 minutes to an hour swapping lies with my friends, the 2C rate is a nice compromise (plus, they're not really fully depleted anyway).
Now against this I keep an eye on ambient temperatures. This is because if it's too hot/cold, NiCd batteries don't perform as well and voltage will drop off more quickly - this is a well recognized response. I.e. above 90°F or below 50°F ambient I adjust my charge habits and perhaps charge after three flights instead of four. Also, when it's hot outside, I wait longer for a battery to cool if it's warm to the touch, and then never exceed 2C charge rate since residual heat may be at its core. Though in truth, this really isn't much of an issue with flight packs as we don't deplete them that fast! Also, when it's colder (though this has become somewhat academic since my living in Florida has weakened my blood and my desire to stand around when it dips below 60°F), I may charge at 3C because a little core temperature boost is a good thing.
Speaking of balancing the Tiger. First, I don't fly with a horizontal fin and I also use a carbon vertical fin and thus, don't have an issue with balance when using the 2400 mAH pack. Furthermore, I mount the governor body on top of the forwardmost servo using a piece of Velcro® and plenty of foam for both battery and receiver on the radio platform. In addition to this, I rarely cut out the white plastic canopy material under the windshield area (the smoke plastic) anymore because it makes the unit stronger and affords greater protection to my equipment when the inevitable happens. I figure the 3/4 of an ounce helps my balance situation and the power-to-weight of the 50-class makes it something of a non-issue for me. That said, the 3300 mAH battery is probably overkill, but some guys don't have my regular monitoring habits and hence, my mention of it.
Meanwhile, sitting on my desk are two new 2400 mAH packs to replace two which have seen much use/abuse during the 2005 flying season. I also have a new pair of switches to replace those in the two helicopters in question. While I can cycle and get 85% and 88% respectively (of the original capacity) from when the packs were first installed, I won't risk a heli on them. Hence, I'll nip off what connectors look viable and toss and replace them both (it's part of the gearing up for the new flying season procedure). As I write this I'm looking at them both cycling here on my desk. I'll cycle them perhaps 5 more times between now and the weekend. I've fiddled with the switches also (usually whilst I'm on the phone) by turning them on/off many times). Finally, later this week, I'll write both the capacity and the date on the batteries with a Sharpie® pen, install both them and the switches, and be good to go for 2006!
My 2¢
John Beech - GM (and janitor)
Audacity Models |
. Digitals will usually only get that many flights before showing a low voltage reading on that mah battery. I was using 2400mah batteries and only put as many as four flights on them. Afterwards I'd charge them again if I was going to fly anymore that day. Now that I've moved to digitals I'm going to watch what the 3000mah sub c batteries that I'm using now until I can get some idea as to how much I can fly until a charge is needed.
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